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acrac_69481_25

Head Trauma PCAs

Its sensitivity for contrast leakage from the subarachnoid space into the sinonasal or tympanomastoid cavities depends on the rate of CSF leak and ranges between 85% and 92% in patients with an active leak versus 40% in patients with an inactive or intermittent leak [64]. Noninvasive noncontrast HRCT has a high sensitivity of 84% to 95% and has replaced traditional use of minimally invasive contrast-enhanced CT cisternography in the initial imaging evaluation of suspected CSF leak with laboratory confirmation [64,65]. No additional preoperative neuroimaging is necessary when a single skull base defect is identified on the HRCT; when there are multiple potential CSF leak sites, then follow-up CT cisternography is indicated [58,64]. Head Trauma FDG-PET/CT Brain There is no relevant literature to support the use of FDG-PET/CT in the initial imaging evaluation of suspected CSF leak. HMPAO SPECT or SPECT/CT Brain There is no relevant literature to support the use of SPECT in the initial imaging evaluation of suspected CSF leak. MR Spectroscopy Head There is no relevant literature to support the use of MRS in the initial imaging evaluation of suspected CSF leak. MRI Functional (fMRI) Head There is no relevant literature to support the use of fMRI in the initial imaging evaluation of suspected CSF leak. MRI Head MR cisternography is the use of high-resolution T2-weighted or steady-state free precession sequences to look for CSF communication or meningoencephalocele across a defect in the skull base. It is a second-line noninvasive imaging option in the setting of suspected CSF leak with laboratory confirmation that has a reported accuracy of 89% and sensitivity of 87%, which is lower than HRCT [66]. It may be useful as a follow-up study when there is a suspected meningoencephalocele on HRCT (eg, soft-tissue mass with bone erosion) or when preoperative HRCT is unable to pinpoint a single osseous defect in the skull base.

Head Trauma PCAs. Its sensitivity for contrast leakage from the subarachnoid space into the sinonasal or tympanomastoid cavities depends on the rate of CSF leak and ranges between 85% and 92% in patients with an active leak versus 40% in patients with an inactive or intermittent leak [64]. Noninvasive noncontrast HRCT has a high sensitivity of 84% to 95% and has replaced traditional use of minimally invasive contrast-enhanced CT cisternography in the initial imaging evaluation of suspected CSF leak with laboratory confirmation [64,65]. No additional preoperative neuroimaging is necessary when a single skull base defect is identified on the HRCT; when there are multiple potential CSF leak sites, then follow-up CT cisternography is indicated [58,64]. Head Trauma FDG-PET/CT Brain There is no relevant literature to support the use of FDG-PET/CT in the initial imaging evaluation of suspected CSF leak. HMPAO SPECT or SPECT/CT Brain There is no relevant literature to support the use of SPECT in the initial imaging evaluation of suspected CSF leak. MR Spectroscopy Head There is no relevant literature to support the use of MRS in the initial imaging evaluation of suspected CSF leak. MRI Functional (fMRI) Head There is no relevant literature to support the use of fMRI in the initial imaging evaluation of suspected CSF leak. MRI Head MR cisternography is the use of high-resolution T2-weighted or steady-state free precession sequences to look for CSF communication or meningoencephalocele across a defect in the skull base. It is a second-line noninvasive imaging option in the setting of suspected CSF leak with laboratory confirmation that has a reported accuracy of 89% and sensitivity of 87%, which is lower than HRCT [66]. It may be useful as a follow-up study when there is a suspected meningoencephalocele on HRCT (eg, soft-tissue mass with bone erosion) or when preoperative HRCT is unable to pinpoint a single osseous defect in the skull base.

69481

acrac_69371_0

Pretreatment Detection Surveillance and Staging of Prostate Cancer

Introduction/Background Prostate cancer ranks second only after lung cancer as a leading cause of cancer-related deaths in American patients. In 2020, an estimated 191,930 American patients were diagnosed with prostate cancer, and 33,330 died of the disease [1]. In addition to the personal toll of these deaths, there is a substantial amount of direct economic costs related to prostate cancer in the Unites States at an estimated $10 billion per year [2]. The primary goal during pretreatment evaluation of prostate cancer is disease detection, localization, and characterization, that is, establishing disease extent, both local and distant, and aggressiveness, because these drive patient outcomes in terms of recurrence and survival. Reprint requests to: [email protected] Special Imaging Considerations A few emerging imaging techniques have not yet made their way into mainstream clinical practice, showing the potential to improve detection of the primary tumor, nodal, and distant metastatic disease in addition to achieving better risk stratification. Studies on advanced ultrasound (US) techniques have focused on assessment of the primary prostate tumor [31-36]. For example, a recent meta-analysis showed that shear wave elastography had a pooled sensitivity and specificity of 83% and 85%, respectively [31]. In addition, targeted biopsy using real-time elastography was able to improve the Gleason score assignment when added to systematic biopsy than systematic biopsy alone (68.3% versus 56.7%) [32]. High-resolution micro-US has also shown potential to improve detection of clinically significant prostate cancer [33]. Furthermore, when a multiparametric approach was used for US using B-mode, shear wave elastography and contrast-enhanced US, it was able to improve the sensitivity in detecting index lesions compared with B-mode alone (74% versus 55%) [34].

Pretreatment Detection Surveillance and Staging of Prostate Cancer. Introduction/Background Prostate cancer ranks second only after lung cancer as a leading cause of cancer-related deaths in American patients. In 2020, an estimated 191,930 American patients were diagnosed with prostate cancer, and 33,330 died of the disease [1]. In addition to the personal toll of these deaths, there is a substantial amount of direct economic costs related to prostate cancer in the Unites States at an estimated $10 billion per year [2]. The primary goal during pretreatment evaluation of prostate cancer is disease detection, localization, and characterization, that is, establishing disease extent, both local and distant, and aggressiveness, because these drive patient outcomes in terms of recurrence and survival. Reprint requests to: [email protected] Special Imaging Considerations A few emerging imaging techniques have not yet made their way into mainstream clinical practice, showing the potential to improve detection of the primary tumor, nodal, and distant metastatic disease in addition to achieving better risk stratification. Studies on advanced ultrasound (US) techniques have focused on assessment of the primary prostate tumor [31-36]. For example, a recent meta-analysis showed that shear wave elastography had a pooled sensitivity and specificity of 83% and 85%, respectively [31]. In addition, targeted biopsy using real-time elastography was able to improve the Gleason score assignment when added to systematic biopsy than systematic biopsy alone (68.3% versus 56.7%) [32]. High-resolution micro-US has also shown potential to improve detection of clinically significant prostate cancer [33]. Furthermore, when a multiparametric approach was used for US using B-mode, shear wave elastography and contrast-enhanced US, it was able to improve the sensitivity in detecting index lesions compared with B-mode alone (74% versus 55%) [34].

69371

acrac_69371_1

Pretreatment Detection Surveillance and Staging of Prostate Cancer

Regarding assessment of lymph nodes, MR using ultrasmall superparamagnetic iron oxide (USPIO) has shown promise to detect even micrometastatic deposits [37,38]. Two agents, ferumoxtran-10 and ferumoxytol, have been investigated based on their lymphotropic properties, accumulating in normal but not metastatic lymph nodes after injected intravenously. In a prospective multicenter study of intermediate- and high-risk patients with prostate cancer, ferumoxtran-10 showed significantly higher sensitivity (82% versus 34%) than CT with a similar specificity (93% versus 97%) [37]. Moreover, when ferumoxtran-10-based USPIO MRI was performed in conjunction with diffusion-weighted imaging, it yielded impressive results even in normal-sized lymph nodes (sensitivities and specificities of 65%-75% and 93%-96%) [38]. Nevertheless, issues related to iron overload and potential life- threatening allergic reactions have been raised, which need to be addressed before its usage in pretreatment prostate imaging. Pretreatment Detection of Prostate Cancer Choline PET/CT Skull Base to Mid-Thigh There is limited evidence to support the use of choline PET/CT for initial imaging of patients with clinically suspected prostate cancer and no prior biopsy. Choline PET/MRI Skull Base to Mid-Thigh There is limited evidence to support the use of choline PET/MRI for initial imaging of patients with clinically suspected prostate cancer and no prior biopsy. CT Abdomen and Pelvis With IV Contrast There is limited evidence to support the use of CT abdomen and pelvis with intravenous (IV) contrast for initial imaging of patients with clinically suspected prostate cancer and no prior biopsy. CT Abdomen and Pelvis Without and With IV Contrast There is limited evidence to support the use of CT abdomen and pelvis without and with IV contrast for initial imaging of patients with clinically suspected prostate cancer and no prior biopsy.

Pretreatment Detection Surveillance and Staging of Prostate Cancer. Regarding assessment of lymph nodes, MR using ultrasmall superparamagnetic iron oxide (USPIO) has shown promise to detect even micrometastatic deposits [37,38]. Two agents, ferumoxtran-10 and ferumoxytol, have been investigated based on their lymphotropic properties, accumulating in normal but not metastatic lymph nodes after injected intravenously. In a prospective multicenter study of intermediate- and high-risk patients with prostate cancer, ferumoxtran-10 showed significantly higher sensitivity (82% versus 34%) than CT with a similar specificity (93% versus 97%) [37]. Moreover, when ferumoxtran-10-based USPIO MRI was performed in conjunction with diffusion-weighted imaging, it yielded impressive results even in normal-sized lymph nodes (sensitivities and specificities of 65%-75% and 93%-96%) [38]. Nevertheless, issues related to iron overload and potential life- threatening allergic reactions have been raised, which need to be addressed before its usage in pretreatment prostate imaging. Pretreatment Detection of Prostate Cancer Choline PET/CT Skull Base to Mid-Thigh There is limited evidence to support the use of choline PET/CT for initial imaging of patients with clinically suspected prostate cancer and no prior biopsy. Choline PET/MRI Skull Base to Mid-Thigh There is limited evidence to support the use of choline PET/MRI for initial imaging of patients with clinically suspected prostate cancer and no prior biopsy. CT Abdomen and Pelvis With IV Contrast There is limited evidence to support the use of CT abdomen and pelvis with intravenous (IV) contrast for initial imaging of patients with clinically suspected prostate cancer and no prior biopsy. CT Abdomen and Pelvis Without and With IV Contrast There is limited evidence to support the use of CT abdomen and pelvis without and with IV contrast for initial imaging of patients with clinically suspected prostate cancer and no prior biopsy.

69371

acrac_69371_2

Pretreatment Detection Surveillance and Staging of Prostate Cancer

CT Abdomen and Pelvis Without IV Contrast There is limited evidence to support the use of CT abdomen and pelvis without IV contrast for initial imaging of patients with clinically suspected prostate cancer and no prior biopsy. CT Chest, Abdomen, and Pelvis With IV Contrast There is limited evidence to support the use of CT chest, abdomen, and pelvis with IV contrast for initial imaging of patients with clinically suspected prostate cancer and no prior biopsy. CT Chest, Abdomen, and Pelvis Without and With IV Contrast There is limited evidence to support the use of CT chest, abdomen, and pelvis without and with IV contrast for initial imaging of patients with clinically suspected prostate cancer and no prior biopsy. CT Chest, Abdomen, and Pelvis Without IV Contrast There is limited evidence to support the use of CT chest, abdomen, and pelvis without IV contrast for initial imaging of patients with clinically suspected prostate cancer and no prior biopsy. FDG-PET/CT Whole Body Because prostate cancer and metastases from it are generally not fluorine-18-2-fluoro-2-deoxy-D-glucose (FDG)- avid unlike most other malignancies, FDG-PET/CT may not be beneficial as part of initial imaging. FDG-PET/MRI Skull Base to Mid-Thigh Because prostate cancer and metastases from it are generally not FDG-avid unlike most other malignancies, FDG- PET/MRI may not be beneficial as part of initial imaging. Fluciclovine PET/CT Skull Base to Mid-Thigh There is limited evidence to support the use of fluciclovine PET/CT for initial imaging of patients with clinically suspected prostate cancer and no prior biopsy. Fluciclovine PET/MRI Skull Base to Mid-Thigh There is limited evidence to support the use of fluciclovine PET/MRI for initial imaging of patients with clinically suspected prostate cancer and no prior biopsy.

Pretreatment Detection Surveillance and Staging of Prostate Cancer. CT Abdomen and Pelvis Without IV Contrast There is limited evidence to support the use of CT abdomen and pelvis without IV contrast for initial imaging of patients with clinically suspected prostate cancer and no prior biopsy. CT Chest, Abdomen, and Pelvis With IV Contrast There is limited evidence to support the use of CT chest, abdomen, and pelvis with IV contrast for initial imaging of patients with clinically suspected prostate cancer and no prior biopsy. CT Chest, Abdomen, and Pelvis Without and With IV Contrast There is limited evidence to support the use of CT chest, abdomen, and pelvis without and with IV contrast for initial imaging of patients with clinically suspected prostate cancer and no prior biopsy. CT Chest, Abdomen, and Pelvis Without IV Contrast There is limited evidence to support the use of CT chest, abdomen, and pelvis without IV contrast for initial imaging of patients with clinically suspected prostate cancer and no prior biopsy. FDG-PET/CT Whole Body Because prostate cancer and metastases from it are generally not fluorine-18-2-fluoro-2-deoxy-D-glucose (FDG)- avid unlike most other malignancies, FDG-PET/CT may not be beneficial as part of initial imaging. FDG-PET/MRI Skull Base to Mid-Thigh Because prostate cancer and metastases from it are generally not FDG-avid unlike most other malignancies, FDG- PET/MRI may not be beneficial as part of initial imaging. Fluciclovine PET/CT Skull Base to Mid-Thigh There is limited evidence to support the use of fluciclovine PET/CT for initial imaging of patients with clinically suspected prostate cancer and no prior biopsy. Fluciclovine PET/MRI Skull Base to Mid-Thigh There is limited evidence to support the use of fluciclovine PET/MRI for initial imaging of patients with clinically suspected prostate cancer and no prior biopsy.

69371

acrac_69371_3

Pretreatment Detection Surveillance and Staging of Prostate Cancer

Fluoride PET/CT Whole Body There is limited evidence to support the use of fluoride PET/CT for initial imaging of patients with clinically suspected prostate cancer and no prior biopsy. MRI Abdomen and Pelvis Without and With IV Contrast There is limited evidence to support the use of MRI abdomen and pelvis without and with IV contrast for initial imaging of patients with clinically suspected prostate cancer and no prior biopsy. Pretreatment Detection of Prostate Cancer MRI Abdomen and Pelvis Without IV Contrast There is limited evidence to support the use of MRI abdomen and pelvis without IV contrast for initial imaging of patients with clinically suspected prostate cancer and no prior biopsy. MRI Pelvis Without IV Contrast More recently, there has been increase in the performance of MRI pelvis without IV contrast, albeit with controversy regarding the additive benefit of IV gadolinium-based contrast media for assessing prostate cancer. Unlike diffusion-weighted imaging, which is undoubtedly an essential component of prostate MRI, there has been debate over whether dynamic contrast-enhanced imaging should be retained, used but limited to assessing the presence of early and/or contemporaneous enhancement (as in the current PI-RADS schema), or even omitted altogether [50,51]. Despite the notion that detection of prostate cancer could be improved by using dynamic contrast-enhanced imaging, owing to the fact that prostate cancer typically enhances more rapidly and washes out more quickly than benign prostatic tissue, many studies have shown that the incremental diagnostic yield is minimal [52-54]. For instance, in a meta-analysis of 20 studies (2,142 patients) performing a head-to-head comparison of biparametric and multiparametric MRI, sensitivity and specificity were similar: 0.74 (95% CI: 0.66-0.81) and 0.90 (95% CI: 0.86-0.93) for biparametric and 0.76 (95% CI: 0.69-0.82) and 0.89 (95% CI: 0.85-0.93) for multiparametric, respectively [54].

Pretreatment Detection Surveillance and Staging of Prostate Cancer. Fluoride PET/CT Whole Body There is limited evidence to support the use of fluoride PET/CT for initial imaging of patients with clinically suspected prostate cancer and no prior biopsy. MRI Abdomen and Pelvis Without and With IV Contrast There is limited evidence to support the use of MRI abdomen and pelvis without and with IV contrast for initial imaging of patients with clinically suspected prostate cancer and no prior biopsy. Pretreatment Detection of Prostate Cancer MRI Abdomen and Pelvis Without IV Contrast There is limited evidence to support the use of MRI abdomen and pelvis without IV contrast for initial imaging of patients with clinically suspected prostate cancer and no prior biopsy. MRI Pelvis Without IV Contrast More recently, there has been increase in the performance of MRI pelvis without IV contrast, albeit with controversy regarding the additive benefit of IV gadolinium-based contrast media for assessing prostate cancer. Unlike diffusion-weighted imaging, which is undoubtedly an essential component of prostate MRI, there has been debate over whether dynamic contrast-enhanced imaging should be retained, used but limited to assessing the presence of early and/or contemporaneous enhancement (as in the current PI-RADS schema), or even omitted altogether [50,51]. Despite the notion that detection of prostate cancer could be improved by using dynamic contrast-enhanced imaging, owing to the fact that prostate cancer typically enhances more rapidly and washes out more quickly than benign prostatic tissue, many studies have shown that the incremental diagnostic yield is minimal [52-54]. For instance, in a meta-analysis of 20 studies (2,142 patients) performing a head-to-head comparison of biparametric and multiparametric MRI, sensitivity and specificity were similar: 0.74 (95% CI: 0.66-0.81) and 0.90 (95% CI: 0.86-0.93) for biparametric and 0.76 (95% CI: 0.69-0.82) and 0.89 (95% CI: 0.85-0.93) for multiparametric, respectively [54].

69371

acrac_69371_4

Pretreatment Detection Surveillance and Staging of Prostate Cancer

Omitting dynamic contrast-enhanced imaging additionally offers benefits of decreasing study time. Nevertheless, biparametric MRI is not yet widely adopted, and it is recommended that when performed, several requirements need to be met, such as good image quality (especially diffusion-weighted imaging), potential radiologist monitoring, and a safety net for missing significant cancers (eg, PSA follow-up). MRI Whole Body Without and With IV Contrast There is limited evidence to support the use of MRI whole body without and with IV contrast for initial imaging of patients with clinically suspected prostate cancer and no prior biopsy. MRI Whole Body Without IV Contrast There is limited evidence to support the use of MRI whole body without IV contrast for initial imaging of patients with clinically suspected prostate cancer and no prior biopsy. PSMA PET/CT Skull Base to Mid-Thigh There is limited evidence to support the use of prostate-specific membrane antigen (PSMA) PET/CT (or PET/MRI) for initial imaging of patients with clinically suspected prostate cancer and no prior biopsy. TRUS Prostate In North America, TRUS is generally performed by urologists for purposes of localizing the prostate gland (not the cancer) prior to systematic biopsy. Conventional grayscale TRUS is not widely used for localizing the tumor, first because lesions (usually hypoechoic in appearance) are visible only in a small proportion (11%-35%) of patients [65]. In a study of 142 patients, grayscale TRUS was able to detect only 62.2% of lesions visible on multiparametric MRI [66]. Second, only a small proportion (17%-57%) of those hypoechoic lesions are confirmed to be malignant [65]. In a study of 31,296 cores obtained from 3,912 consecutive patients undergoing TRUS with biopsy, there was no statistically significant association between the presence of a hypoechoic lesion and the detection of cancer [67].

Pretreatment Detection Surveillance and Staging of Prostate Cancer. Omitting dynamic contrast-enhanced imaging additionally offers benefits of decreasing study time. Nevertheless, biparametric MRI is not yet widely adopted, and it is recommended that when performed, several requirements need to be met, such as good image quality (especially diffusion-weighted imaging), potential radiologist monitoring, and a safety net for missing significant cancers (eg, PSA follow-up). MRI Whole Body Without and With IV Contrast There is limited evidence to support the use of MRI whole body without and with IV contrast for initial imaging of patients with clinically suspected prostate cancer and no prior biopsy. MRI Whole Body Without IV Contrast There is limited evidence to support the use of MRI whole body without IV contrast for initial imaging of patients with clinically suspected prostate cancer and no prior biopsy. PSMA PET/CT Skull Base to Mid-Thigh There is limited evidence to support the use of prostate-specific membrane antigen (PSMA) PET/CT (or PET/MRI) for initial imaging of patients with clinically suspected prostate cancer and no prior biopsy. TRUS Prostate In North America, TRUS is generally performed by urologists for purposes of localizing the prostate gland (not the cancer) prior to systematic biopsy. Conventional grayscale TRUS is not widely used for localizing the tumor, first because lesions (usually hypoechoic in appearance) are visible only in a small proportion (11%-35%) of patients [65]. In a study of 142 patients, grayscale TRUS was able to detect only 62.2% of lesions visible on multiparametric MRI [66]. Second, only a small proportion (17%-57%) of those hypoechoic lesions are confirmed to be malignant [65]. In a study of 31,296 cores obtained from 3,912 consecutive patients undergoing TRUS with biopsy, there was no statistically significant association between the presence of a hypoechoic lesion and the detection of cancer [67].

69371

acrac_69371_5

Pretreatment Detection Surveillance and Staging of Prostate Cancer

Therefore, in isolation, TRUS is inaccurate for prostate cancer detection and is not beneficial for this purpose [65]. Variant 2: Clinically suspected prostate cancer. Negative TRUS-guided biopsy. Initial diagnosis. Next imaging study. Bone Scan Whole Body There is limited evidence to support the use of bone scan as the next imaging study of patients with clinically suspected prostate cancer unless or until the presence of higher-risk disease has been established histologically. Pretreatment Detection of Prostate Cancer Choline PET/CT Skull Base to Mid-Thigh There is limited evidence to support the use of choline PET/CT for initial imaging of patients with clinically suspected prostate cancer unless or until the presence of higher-risk disease has been established histologically. Choline PET/MRI Skull Base to Mid-Thigh There is limited evidence to support the use of choline PET/MRI for initial imaging of patients with clinically suspected prostate cancer unless or until the presence of higher-risk disease has been established histologically. CT Abdomen and Pelvis With IV Contrast There is limited evidence to support the use of CT abdomen and pelvis with IV contrast for initial imaging of patients with clinically suspected prostate cancer unless or until the presence of higher-risk disease has been established histologically. CT Abdomen and Pelvis Without and With IV Contrast There is limited evidence to support the use of CT abdomen and pelvis without and with IV contrast for initial imaging of patients with clinically suspected prostate cancer unless or until the presence of higher-risk disease has been established histologically. CT Abdomen and Pelvis Without IV Contrast There is limited evidence to support the use of CT abdomen and pelvis without IV contrast for initial imaging of patients with clinically suspected prostate cancer unless or until the presence of higher-risk disease has been established histologically.

Pretreatment Detection Surveillance and Staging of Prostate Cancer. Therefore, in isolation, TRUS is inaccurate for prostate cancer detection and is not beneficial for this purpose [65]. Variant 2: Clinically suspected prostate cancer. Negative TRUS-guided biopsy. Initial diagnosis. Next imaging study. Bone Scan Whole Body There is limited evidence to support the use of bone scan as the next imaging study of patients with clinically suspected prostate cancer unless or until the presence of higher-risk disease has been established histologically. Pretreatment Detection of Prostate Cancer Choline PET/CT Skull Base to Mid-Thigh There is limited evidence to support the use of choline PET/CT for initial imaging of patients with clinically suspected prostate cancer unless or until the presence of higher-risk disease has been established histologically. Choline PET/MRI Skull Base to Mid-Thigh There is limited evidence to support the use of choline PET/MRI for initial imaging of patients with clinically suspected prostate cancer unless or until the presence of higher-risk disease has been established histologically. CT Abdomen and Pelvis With IV Contrast There is limited evidence to support the use of CT abdomen and pelvis with IV contrast for initial imaging of patients with clinically suspected prostate cancer unless or until the presence of higher-risk disease has been established histologically. CT Abdomen and Pelvis Without and With IV Contrast There is limited evidence to support the use of CT abdomen and pelvis without and with IV contrast for initial imaging of patients with clinically suspected prostate cancer unless or until the presence of higher-risk disease has been established histologically. CT Abdomen and Pelvis Without IV Contrast There is limited evidence to support the use of CT abdomen and pelvis without IV contrast for initial imaging of patients with clinically suspected prostate cancer unless or until the presence of higher-risk disease has been established histologically.

69371

acrac_69371_6

Pretreatment Detection Surveillance and Staging of Prostate Cancer

CT Chest, Abdomen, and Pelvis With IV Contrast There is limited evidence to support the use of CT chest, abdomen, and pelvis with IV contrast for initial imaging of patients with clinically suspected prostate cancer unless or until the presence of higher-risk disease has been established histologically. CT Chest, Abdomen, and Pelvis Without and With IV Contrast There is limited evidence to support the use of CT chest, abdomen, and pelvis without and with IV contrast for initial imaging of patients with clinically suspected prostate cancer unless or until the presence of higher-risk disease has been established histologically. CT Chest, Abdomen, and Pelvis Without IV Contrast There is limited evidence to support the use of CT chest, abdomen, and pelvis without IV contrast for initial imaging of patients with clinically suspected prostate cancer unless or until the presence of higher-risk disease has been established histologically. FDG-PET/CT Whole Body Because prostate cancer and metastases from it are generally not FDG-avid unlike most other malignancies, FDG- PET/CT may not be beneficial as part of initial imaging. FDG-PET/MRI Skull Base to Mid-Thigh Because prostate cancer and metastases from it are generally not FDG-avid unlike most other malignancies, FDG- PET/MRI may not be beneficial as part of initial imaging. Fluciclovine PET/CT Skull Base to Mid-Thigh There is limited evidence to support the use of fluciclovine PET/CT for initial imaging of patients with clinically suspected prostate cancer unless or until the presence of higher-risk disease has been established histologically. Fluciclovine PET/MRI Skull Base to Mid-Thigh There is limited evidence to support the use of fluciclovine PET/MRI for initial imaging of patients with clinically suspected prostate cancer unless or until the presence of higher-risk disease has been established histologically.

Pretreatment Detection Surveillance and Staging of Prostate Cancer. CT Chest, Abdomen, and Pelvis With IV Contrast There is limited evidence to support the use of CT chest, abdomen, and pelvis with IV contrast for initial imaging of patients with clinically suspected prostate cancer unless or until the presence of higher-risk disease has been established histologically. CT Chest, Abdomen, and Pelvis Without and With IV Contrast There is limited evidence to support the use of CT chest, abdomen, and pelvis without and with IV contrast for initial imaging of patients with clinically suspected prostate cancer unless or until the presence of higher-risk disease has been established histologically. CT Chest, Abdomen, and Pelvis Without IV Contrast There is limited evidence to support the use of CT chest, abdomen, and pelvis without IV contrast for initial imaging of patients with clinically suspected prostate cancer unless or until the presence of higher-risk disease has been established histologically. FDG-PET/CT Whole Body Because prostate cancer and metastases from it are generally not FDG-avid unlike most other malignancies, FDG- PET/CT may not be beneficial as part of initial imaging. FDG-PET/MRI Skull Base to Mid-Thigh Because prostate cancer and metastases from it are generally not FDG-avid unlike most other malignancies, FDG- PET/MRI may not be beneficial as part of initial imaging. Fluciclovine PET/CT Skull Base to Mid-Thigh There is limited evidence to support the use of fluciclovine PET/CT for initial imaging of patients with clinically suspected prostate cancer unless or until the presence of higher-risk disease has been established histologically. Fluciclovine PET/MRI Skull Base to Mid-Thigh There is limited evidence to support the use of fluciclovine PET/MRI for initial imaging of patients with clinically suspected prostate cancer unless or until the presence of higher-risk disease has been established histologically.

69371

acrac_69371_7

Pretreatment Detection Surveillance and Staging of Prostate Cancer

Fluoride PET/CT Whole Body There is limited evidence to support the use of fluoride PET/CT for initial imaging of patients with clinically suspected prostate cancer unless or until the presence of higher-risk disease has been established histologically. MRI Abdomen and Pelvis Without and With IV Contrast There is limited evidence to support the use of MRI abdomen and pelvis without and with IV contrast for initial imaging of patients with clinically suspected prostate cancer unless or until the presence of higher-risk disease has been established histologically. Pretreatment Detection of Prostate Cancer MRI Abdomen and Pelvis Without IV Contrast There is limited evidence to support the use of MRI abdomen and pelvis without IV contrast for initial imaging of patients with clinically suspected prostate cancer unless or until the presence of higher-risk disease has been established histologically. MRI Pelvis Without IV Contrast In patients with clinically suspected prostate cancer who had a negative TRUS-guided biopsy, imaging without using IV contrast is also a viable option based on the identical rationales for using MRI of the pelvis with IV contrast [29,40,44,45,49]. Nevertheless, controversies exist with regard to balancing between the small incremental yield for detecting clinically significant cancer using IV contrast and potential benefits such as decreased scan time when forgoing IV contrast [50-54]. MRI Whole Body Without and With IV Contrast There is limited evidence to support the use of MRI whole body without and with IV contrast for initial imaging of patients with clinically suspected prostate cancer unless or until the presence of higher-risk disease has been established histologically.

Pretreatment Detection Surveillance and Staging of Prostate Cancer. Fluoride PET/CT Whole Body There is limited evidence to support the use of fluoride PET/CT for initial imaging of patients with clinically suspected prostate cancer unless or until the presence of higher-risk disease has been established histologically. MRI Abdomen and Pelvis Without and With IV Contrast There is limited evidence to support the use of MRI abdomen and pelvis without and with IV contrast for initial imaging of patients with clinically suspected prostate cancer unless or until the presence of higher-risk disease has been established histologically. Pretreatment Detection of Prostate Cancer MRI Abdomen and Pelvis Without IV Contrast There is limited evidence to support the use of MRI abdomen and pelvis without IV contrast for initial imaging of patients with clinically suspected prostate cancer unless or until the presence of higher-risk disease has been established histologically. MRI Pelvis Without IV Contrast In patients with clinically suspected prostate cancer who had a negative TRUS-guided biopsy, imaging without using IV contrast is also a viable option based on the identical rationales for using MRI of the pelvis with IV contrast [29,40,44,45,49]. Nevertheless, controversies exist with regard to balancing between the small incremental yield for detecting clinically significant cancer using IV contrast and potential benefits such as decreased scan time when forgoing IV contrast [50-54]. MRI Whole Body Without and With IV Contrast There is limited evidence to support the use of MRI whole body without and with IV contrast for initial imaging of patients with clinically suspected prostate cancer unless or until the presence of higher-risk disease has been established histologically.

69371

acrac_69371_8

Pretreatment Detection Surveillance and Staging of Prostate Cancer

MRI Whole Body Without IV Contrast There is limited evidence to support the use of MRI whole body without IV contrast for initial imaging of patients with clinically suspected prostate cancer unless or until the presence of higher-risk disease has been established histologically. PSMA PET/CT Skull Base to Mid-Thigh There is limited evidence to support the use of PSMA PET/CT (or PET/MRI) for initial imaging of patients with clinically suspected prostate cancer unless or until the presence of higher-risk disease has been established histologically. TRUS Prostate In isolation, TRUS is inaccurate for prostate cancer detection and is not useful for this purpose [65,66]. TRUS-Guided Biopsy Prostate In patients with clinically suspected prostate cancer who have had 1 negative standard TRUS-guided systematic biopsy, a second TRUS-guided systematic biopsy will be positive in 15% to 20% of cases [73-76], and so a second repeat biopsy in this setting is reasonable. The yield from additional systematic biopsies after a second biopsy falls off rapidly, with reported positive rates of 8% to 17% for the third biopsy and 7% to 12% for the fourth [73-75,77], suggesting alternative approaches such as MRI-targeted biopsy or saturation biopsy may be more useful in this specific setting of patients with 2 or more negative TRUS-guided systematic biopsies and persistent clinical suspicion for prostate cancer. Choline PET/CT Skull Base to Mid-Thigh There is limited evidence to support the use of choline PET/CT for active surveillance of patients with clinically established low-risk prostate cancer. Choline PET/MRI Skull Base to Mid-Thigh There is limited evidence to support the use of choline PET/MRI for active surveillance of patients with clinically established low-risk prostate cancer.

Pretreatment Detection Surveillance and Staging of Prostate Cancer. MRI Whole Body Without IV Contrast There is limited evidence to support the use of MRI whole body without IV contrast for initial imaging of patients with clinically suspected prostate cancer unless or until the presence of higher-risk disease has been established histologically. PSMA PET/CT Skull Base to Mid-Thigh There is limited evidence to support the use of PSMA PET/CT (or PET/MRI) for initial imaging of patients with clinically suspected prostate cancer unless or until the presence of higher-risk disease has been established histologically. TRUS Prostate In isolation, TRUS is inaccurate for prostate cancer detection and is not useful for this purpose [65,66]. TRUS-Guided Biopsy Prostate In patients with clinically suspected prostate cancer who have had 1 negative standard TRUS-guided systematic biopsy, a second TRUS-guided systematic biopsy will be positive in 15% to 20% of cases [73-76], and so a second repeat biopsy in this setting is reasonable. The yield from additional systematic biopsies after a second biopsy falls off rapidly, with reported positive rates of 8% to 17% for the third biopsy and 7% to 12% for the fourth [73-75,77], suggesting alternative approaches such as MRI-targeted biopsy or saturation biopsy may be more useful in this specific setting of patients with 2 or more negative TRUS-guided systematic biopsies and persistent clinical suspicion for prostate cancer. Choline PET/CT Skull Base to Mid-Thigh There is limited evidence to support the use of choline PET/CT for active surveillance of patients with clinically established low-risk prostate cancer. Choline PET/MRI Skull Base to Mid-Thigh There is limited evidence to support the use of choline PET/MRI for active surveillance of patients with clinically established low-risk prostate cancer.

69371

acrac_69371_9

Pretreatment Detection Surveillance and Staging of Prostate Cancer

CT Abdomen and Pelvis With IV Contrast There is limited evidence to support the use of CT abdomen and pelvis with IV contrast for active surveillance of patients with clinically established low-risk prostate cancer. CT Abdomen and Pelvis Without and With IV Contrast There is limited evidence to support the use of CT abdomen and pelvis without and with IV contrast for active surveillance of patients with clinically established low-risk prostate cancer. CT Abdomen and Pelvis Without IV contrast There is limited evidence to support the use of CT abdomen and pelvis without IV contrast for active surveillance of patients with clinically established low-risk prostate cancer. CT Chest, Abdomen, and Pelvis With IV Contrast There is limited evidence to support the use of CT chest, abdomen, and pelvis with IV contrast for active surveillance of patients with clinically established low-risk prostate cancer. CT Chest, Abdomen, and Pelvis Without and With IV Contrast There is limited evidence to support the use of CT chest, abdomen, and pelvis without and with IV contrast for active surveillance of patients with clinically established low-risk prostate cancer. CT Chest, Abdomen, and Pelvis Without IV Contrast There is limited evidence to support the use of CT chest, abdomen, and pelvis without IV contrast for active surveillance of patients with clinically established low-risk prostate cancer. FDG-PET/CT Whole Body Because prostate cancer and metastases from it are generally not FDG-avid unlike most other malignancies, FDG- PET/CT may not be beneficial as part of active surveillance. FDG-PET/MRI Skull Base to Mid-Thigh Because prostate cancer and metastases from it are generally not FDG-avid unlike most other malignancies, FDG- PET/MRI may not be beneficial as part of active surveillance.

Pretreatment Detection Surveillance and Staging of Prostate Cancer. CT Abdomen and Pelvis With IV Contrast There is limited evidence to support the use of CT abdomen and pelvis with IV contrast for active surveillance of patients with clinically established low-risk prostate cancer. CT Abdomen and Pelvis Without and With IV Contrast There is limited evidence to support the use of CT abdomen and pelvis without and with IV contrast for active surveillance of patients with clinically established low-risk prostate cancer. CT Abdomen and Pelvis Without IV contrast There is limited evidence to support the use of CT abdomen and pelvis without IV contrast for active surveillance of patients with clinically established low-risk prostate cancer. CT Chest, Abdomen, and Pelvis With IV Contrast There is limited evidence to support the use of CT chest, abdomen, and pelvis with IV contrast for active surveillance of patients with clinically established low-risk prostate cancer. CT Chest, Abdomen, and Pelvis Without and With IV Contrast There is limited evidence to support the use of CT chest, abdomen, and pelvis without and with IV contrast for active surveillance of patients with clinically established low-risk prostate cancer. CT Chest, Abdomen, and Pelvis Without IV Contrast There is limited evidence to support the use of CT chest, abdomen, and pelvis without IV contrast for active surveillance of patients with clinically established low-risk prostate cancer. FDG-PET/CT Whole Body Because prostate cancer and metastases from it are generally not FDG-avid unlike most other malignancies, FDG- PET/CT may not be beneficial as part of active surveillance. FDG-PET/MRI Skull Base to Mid-Thigh Because prostate cancer and metastases from it are generally not FDG-avid unlike most other malignancies, FDG- PET/MRI may not be beneficial as part of active surveillance.

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acrac_69371_10

Pretreatment Detection Surveillance and Staging of Prostate Cancer

Fluciclovine PET/CT Skull Base to Mid-Thigh There is limited evidence to support the use of fluciclovine PET/CT for active surveillance of patients with clinically established low-risk prostate cancer. Fluciclovine PET/MRI Skull Base to Mid-Thigh There is limited evidence to support the use of fluciclovine PET/MRI for active surveillance of patients with clinically established low-risk prostate cancer. Fluoride PET/CT Whole Body There is limited evidence to support the use of fluoride PET/CT for active surveillance of patients with clinically established low-risk prostate cancer. Pretreatment Detection of Prostate Cancer MRI Abdomen and Pelvis Without and With IV Contrast There is limited evidence to support the use of MRI abdomen and pelvis without and with IV contrast for active surveillance of patients with clinically established low-risk prostate cancer. MRI Abdomen and Pelvis Without IV Contrast There is limited evidence to support the use of MRI abdomen and pelvis without IV contrast for active surveillance of patients with clinically established low-risk prostate cancer. MRI Pelvis Without and With IV Contrast There has been a substantial increase in the role of MRI in active surveillance in terms of detecting/predicting disease progression and identifying targets amenable for biopsy. In a meta-analysis of 43 studies (6,605 patients), the sensitivity and negative predictive value of predicting disease reclassification were 0.60 and 0.75 using 1.5T scanners and 0.81 and 0.78 using 3.0T scanners [81]. In addition, several studies have shown that MRI is at least equivalent or superior to systematic TRUS-guided biopsies in identifying pathological progression during follow- up in patients on active surveillance [82-84].

Pretreatment Detection Surveillance and Staging of Prostate Cancer. Fluciclovine PET/CT Skull Base to Mid-Thigh There is limited evidence to support the use of fluciclovine PET/CT for active surveillance of patients with clinically established low-risk prostate cancer. Fluciclovine PET/MRI Skull Base to Mid-Thigh There is limited evidence to support the use of fluciclovine PET/MRI for active surveillance of patients with clinically established low-risk prostate cancer. Fluoride PET/CT Whole Body There is limited evidence to support the use of fluoride PET/CT for active surveillance of patients with clinically established low-risk prostate cancer. Pretreatment Detection of Prostate Cancer MRI Abdomen and Pelvis Without and With IV Contrast There is limited evidence to support the use of MRI abdomen and pelvis without and with IV contrast for active surveillance of patients with clinically established low-risk prostate cancer. MRI Abdomen and Pelvis Without IV Contrast There is limited evidence to support the use of MRI abdomen and pelvis without IV contrast for active surveillance of patients with clinically established low-risk prostate cancer. MRI Pelvis Without and With IV Contrast There has been a substantial increase in the role of MRI in active surveillance in terms of detecting/predicting disease progression and identifying targets amenable for biopsy. In a meta-analysis of 43 studies (6,605 patients), the sensitivity and negative predictive value of predicting disease reclassification were 0.60 and 0.75 using 1.5T scanners and 0.81 and 0.78 using 3.0T scanners [81]. In addition, several studies have shown that MRI is at least equivalent or superior to systematic TRUS-guided biopsies in identifying pathological progression during follow- up in patients on active surveillance [82-84].

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acrac_69371_11

Pretreatment Detection Surveillance and Staging of Prostate Cancer

In a prospective trial of 172 patients who underwent active surveillance, in which at 3 years 21% experienced pathological progression, MRI using PI-RADS was able to identify many of them (a sensitivity of 61% and a specificity of 80%) [82]. In addition, in a study in which 86 patients who had diffusion-weighted imaging as part of their baseline assessment for active surveillance and followed up for a median of 9.5 years, it was able to predict patients with a shorter time to adverse histology (hazard ratio [HR] = 2.13, 95% CI: 1.17-3.89) and a shorter time to radical treatment (HR 2.54, 95% CI: 1.49-4.32; P < . 001) [83]. MRI can also be used in conjunction with nonimaging biomarkers to better identify patients with an increased risk of biopsy upgrading [84]. MRI Pelvis Without IV Contrast Initial imaging without using IV contrast is also a viable option based on the identical rationales for using MRI of the pelvis with IV contrast [81-84]. Especially, there are studies that specifically address the usage of diffusion- weighted imaging (which is typical done without or prior to administration of IV contrast) for baseline assessment on active surveillance, demonstrating that it was helpful for predicting patients with shorter time to adverse histology and radical treatment [83]. MRI Whole Body Without and With IV Contrast There is limited evidence to support the use of MRI whole body without and with IV contrast for active surveillance of patients with clinically established low-risk prostate cancer. MRI Whole Body Without IV Contrast There is limited evidence to support the use of MRI whole body without IV contrast for active surveillance of patients with clinically established low-risk prostate cancer. PSMA PET/CT Skull Base to Mid-Thigh There is limited evidence to support the use of PSMA PET/CT (or PET/MRI) for active surveillance of patients with clinically established low-risk prostate cancer. Pretreatment Detection of Prostate Cancer

Pretreatment Detection Surveillance and Staging of Prostate Cancer. In a prospective trial of 172 patients who underwent active surveillance, in which at 3 years 21% experienced pathological progression, MRI using PI-RADS was able to identify many of them (a sensitivity of 61% and a specificity of 80%) [82]. In addition, in a study in which 86 patients who had diffusion-weighted imaging as part of their baseline assessment for active surveillance and followed up for a median of 9.5 years, it was able to predict patients with a shorter time to adverse histology (hazard ratio [HR] = 2.13, 95% CI: 1.17-3.89) and a shorter time to radical treatment (HR 2.54, 95% CI: 1.49-4.32; P < . 001) [83]. MRI can also be used in conjunction with nonimaging biomarkers to better identify patients with an increased risk of biopsy upgrading [84]. MRI Pelvis Without IV Contrast Initial imaging without using IV contrast is also a viable option based on the identical rationales for using MRI of the pelvis with IV contrast [81-84]. Especially, there are studies that specifically address the usage of diffusion- weighted imaging (which is typical done without or prior to administration of IV contrast) for baseline assessment on active surveillance, demonstrating that it was helpful for predicting patients with shorter time to adverse histology and radical treatment [83]. MRI Whole Body Without and With IV Contrast There is limited evidence to support the use of MRI whole body without and with IV contrast for active surveillance of patients with clinically established low-risk prostate cancer. MRI Whole Body Without IV Contrast There is limited evidence to support the use of MRI whole body without IV contrast for active surveillance of patients with clinically established low-risk prostate cancer. PSMA PET/CT Skull Base to Mid-Thigh There is limited evidence to support the use of PSMA PET/CT (or PET/MRI) for active surveillance of patients with clinically established low-risk prostate cancer. Pretreatment Detection of Prostate Cancer

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Pretreatment Detection Surveillance and Staging of Prostate Cancer

TRUS Prostate In general, TRUS is inaccurate for prostate cancer detection [65,67] and has a limited accuracy for staging prostate cancer [93]. Other than one retrospective study of 875 patients who demonstrated the association between imaging progression on TRUS and biopsy Gleason upgrade [94], there is lack of evidence to support TRUS in evaluating on active surveillance. TRUS-Guided Biopsy Prostate Many active surveillance programs incorporate serial PSA testing and some form of serial biopsy regimen, either in the form of 1) systemic biopsy only or 2) systemic biopsy with MRI-targeted biopsy of a suspicious lesion on MRI. Because some tumors are invisible on MRI [82] and missed by MRI-targeted biopsies [91,92], even when performing an MRI-targeted biopsy as part of active surveillance, concurrent systemic biopsies cannot be omitted at the moment. Choline PET/CT Skull Base to Mid-Thigh Choline PET, although it was approved by the FDA in 2013 for evaluating recurrence, has been widely investigated on its ability to detect nodal and distant metastases for pretreatment assessment of prostate cancer. The pooled sensitivity of choline PET/CT is low (0.57, 95% CI: 0.42-0.70) for detecting nodal metastases prior to treatment despite its high specificity (0.94, 95% CI: 0.89-0.97) in a meta-analysis of 7 studies (627 patients) [98]. Nevertheless, in patients with intermediate- and high-risk prostate cancer, choline PET/CT and PET/MRI has shown to identify more nodal and distant metastatic lesions than conventional imaging [96,98]. For example, in a study of 48 patients, choline PET/CT showed higher sensitivity (46.2% versus 69.2%) with identical specificity (92.3%) for detecting nodal metastases [99]. This in turn has shown to change in management in 33% to 71% of patients [99,100].

Pretreatment Detection Surveillance and Staging of Prostate Cancer. TRUS Prostate In general, TRUS is inaccurate for prostate cancer detection [65,67] and has a limited accuracy for staging prostate cancer [93]. Other than one retrospective study of 875 patients who demonstrated the association between imaging progression on TRUS and biopsy Gleason upgrade [94], there is lack of evidence to support TRUS in evaluating on active surveillance. TRUS-Guided Biopsy Prostate Many active surveillance programs incorporate serial PSA testing and some form of serial biopsy regimen, either in the form of 1) systemic biopsy only or 2) systemic biopsy with MRI-targeted biopsy of a suspicious lesion on MRI. Because some tumors are invisible on MRI [82] and missed by MRI-targeted biopsies [91,92], even when performing an MRI-targeted biopsy as part of active surveillance, concurrent systemic biopsies cannot be omitted at the moment. Choline PET/CT Skull Base to Mid-Thigh Choline PET, although it was approved by the FDA in 2013 for evaluating recurrence, has been widely investigated on its ability to detect nodal and distant metastases for pretreatment assessment of prostate cancer. The pooled sensitivity of choline PET/CT is low (0.57, 95% CI: 0.42-0.70) for detecting nodal metastases prior to treatment despite its high specificity (0.94, 95% CI: 0.89-0.97) in a meta-analysis of 7 studies (627 patients) [98]. Nevertheless, in patients with intermediate- and high-risk prostate cancer, choline PET/CT and PET/MRI has shown to identify more nodal and distant metastatic lesions than conventional imaging [96,98]. For example, in a study of 48 patients, choline PET/CT showed higher sensitivity (46.2% versus 69.2%) with identical specificity (92.3%) for detecting nodal metastases [99]. This in turn has shown to change in management in 33% to 71% of patients [99,100].

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acrac_69371_13

Pretreatment Detection Surveillance and Staging of Prostate Cancer

Choline PET/MRI Skull Base to Mid-Thigh Choline PET/MRI is less commonly used than choline PET/CT but can be considered in the pretreatment assessment of prostate cancer based on the same principles that it better detects nodal and distant metastases than CT and bone scan [96,98-100]. For example, in a study of 48 patients with intermediate- and high-risk disease, choline PET/CT showed a higher sensitivity (46.2% versus 69.2%) with identical specificity (92.3%) for detecting nodal metastases [99]. In a prospective study specifically assessing choline PET/MRI in 58 patients, it was superior to CT and bone scan for detecting distant metastases (100% versus 63.6%, respectively) [101]. CT Abdomen and Pelvis With IV Contrast CT abdomen and pelvis with IV contrast for nodal staging is generally useful in intermediate-risk patients because the a priori risk of nodal disease exceeds 10% [20]. CT Abdomen and Pelvis Without and With IV Contrast There is limited evidence to support the use of CT abdomen and pelvis without and with IV contrast because obtaining CT with both techniques does not provide additional benefit in terms of detecting nodal and distant metastases. Pretreatment Detection of Prostate Cancer CT Abdomen and Pelvis Without IV Contrast CT abdomen and pelvis without IV contrast can be a viable option as an alternative for using IV contrast for nodal staging because it is generally useful in intermediate-risk patients because the a priori risk of nodal disease exceeds 10% [20]. However, it should be recognized that without using IV contrast there is possibility of less optimal detection of metastases to visceral organs. CT Chest, Abdomen, and Pelvis With IV Contrast CT chest, abdomen, and pelvis with IV contrast for nodal staging is generally useful in intermediate-risk patients because the a priori risk of nodal disease exceeds 10% [20].

Pretreatment Detection Surveillance and Staging of Prostate Cancer. Choline PET/MRI Skull Base to Mid-Thigh Choline PET/MRI is less commonly used than choline PET/CT but can be considered in the pretreatment assessment of prostate cancer based on the same principles that it better detects nodal and distant metastases than CT and bone scan [96,98-100]. For example, in a study of 48 patients with intermediate- and high-risk disease, choline PET/CT showed a higher sensitivity (46.2% versus 69.2%) with identical specificity (92.3%) for detecting nodal metastases [99]. In a prospective study specifically assessing choline PET/MRI in 58 patients, it was superior to CT and bone scan for detecting distant metastases (100% versus 63.6%, respectively) [101]. CT Abdomen and Pelvis With IV Contrast CT abdomen and pelvis with IV contrast for nodal staging is generally useful in intermediate-risk patients because the a priori risk of nodal disease exceeds 10% [20]. CT Abdomen and Pelvis Without and With IV Contrast There is limited evidence to support the use of CT abdomen and pelvis without and with IV contrast because obtaining CT with both techniques does not provide additional benefit in terms of detecting nodal and distant metastases. Pretreatment Detection of Prostate Cancer CT Abdomen and Pelvis Without IV Contrast CT abdomen and pelvis without IV contrast can be a viable option as an alternative for using IV contrast for nodal staging because it is generally useful in intermediate-risk patients because the a priori risk of nodal disease exceeds 10% [20]. However, it should be recognized that without using IV contrast there is possibility of less optimal detection of metastases to visceral organs. CT Chest, Abdomen, and Pelvis With IV Contrast CT chest, abdomen, and pelvis with IV contrast for nodal staging is generally useful in intermediate-risk patients because the a priori risk of nodal disease exceeds 10% [20].

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acrac_69371_14

Pretreatment Detection Surveillance and Staging of Prostate Cancer

CT Chest, Abdomen, and Pelvis Without and With IV Contrast There is limited evidence to support the use of CT chest, abdomen, and pelvis without and with IV contrast because obtaining CT with both techniques does not provide additional benefit in terms of detecting nodal and distant metastases. CT Chest, Abdomen, and Pelvis Without IV Contrast CT chest, abdomen, and pelvis without IV contrast for nodal staging is generally useful in intermediate-risk patients because the a priori risk of nodal disease exceeds 10% [20]. However, it should be recognized that without using IV contrast there is a possibility of less optimal detection of metastases to visceral organs. FDG-PET/CT Whole Body Because prostate cancer and metastases from it are generally not FDG-avid unlike most other malignancies, FDG- PET/CT may not be beneficial as part of staging clinically established intermediate-risk prostate cancer. FDG-PET/MRI Skull Base to Mid-Thigh Because prostate cancer and metastases from it are generally not FDG-avid unlike most other malignancies, FDG- PET/MRI may not be beneficial as part of staging clinically established intermediate-risk prostate cancer. Fluciclovine PET/CT Skull Base to Mid-Thigh Although fluciclovine PET/CT is primarily used in the recurrent setting, it can also be considered in the pretreatment assessment of prostate cancer based on its ability to better detect nodal and distant metastases than CT and bone scan [98,102-105]. The specificity of fluciclovine PET/CT is high (0.98, 95% CI: 0.88-1.00) [98], and in a study of 57 patients, it demonstrated higher sensitivity for detecting nodal metastases (55.3% versus 33.3%) and was able to identify 12.3% (7/57) additional patients with distant metastasis when compared to conventional imaging (bone scan and CT) in patients with intermediate- and high-risk disease [106].

Pretreatment Detection Surveillance and Staging of Prostate Cancer. CT Chest, Abdomen, and Pelvis Without and With IV Contrast There is limited evidence to support the use of CT chest, abdomen, and pelvis without and with IV contrast because obtaining CT with both techniques does not provide additional benefit in terms of detecting nodal and distant metastases. CT Chest, Abdomen, and Pelvis Without IV Contrast CT chest, abdomen, and pelvis without IV contrast for nodal staging is generally useful in intermediate-risk patients because the a priori risk of nodal disease exceeds 10% [20]. However, it should be recognized that without using IV contrast there is a possibility of less optimal detection of metastases to visceral organs. FDG-PET/CT Whole Body Because prostate cancer and metastases from it are generally not FDG-avid unlike most other malignancies, FDG- PET/CT may not be beneficial as part of staging clinically established intermediate-risk prostate cancer. FDG-PET/MRI Skull Base to Mid-Thigh Because prostate cancer and metastases from it are generally not FDG-avid unlike most other malignancies, FDG- PET/MRI may not be beneficial as part of staging clinically established intermediate-risk prostate cancer. Fluciclovine PET/CT Skull Base to Mid-Thigh Although fluciclovine PET/CT is primarily used in the recurrent setting, it can also be considered in the pretreatment assessment of prostate cancer based on its ability to better detect nodal and distant metastases than CT and bone scan [98,102-105]. The specificity of fluciclovine PET/CT is high (0.98, 95% CI: 0.88-1.00) [98], and in a study of 57 patients, it demonstrated higher sensitivity for detecting nodal metastases (55.3% versus 33.3%) and was able to identify 12.3% (7/57) additional patients with distant metastasis when compared to conventional imaging (bone scan and CT) in patients with intermediate- and high-risk disease [106].

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acrac_69371_15

Pretreatment Detection Surveillance and Staging of Prostate Cancer

Fluciclovine PET/MRI Skull Base to Mid-Thigh Fluciclovine PET/MRI is less commonly used than fluciclovine PET/CT but shares similar principles and can be considered in the pretreatment assessment of prostate cancer based on its ability to better detect nodal and distant metastases than CT and bone scan [102,105]. The specificity of fluciclovine PET/CT is high (0.98, 95% CI: 0.88- 1.00) [98], and in a study of 57 patients, it demonstrated a higher sensitivity for detecting nodal metastases (55.3% versus 33.3%) and was able to identify 12.3% (7/57) additional patients with distant metastasis when compared with conventional imaging (bone scan and CT) in patients with intermediate- and high-risk disease [106]. Although no specific study deals with only patients with intermediate-risk disease, it is notable that in a study of 28 patients with high-risk disease, the sensitivity and specificity of fluciclovine PET/MRI for detecting nodal metastases was 40% and 100%, respectively [105]. Also, fluciclovine PET/MRI has been shown to potentially improve characterization of the primary tumor compared with PET/CT [103]. Pretreatment Detection of Prostate Cancer MRI Abdomen and Pelvis Without and With IV Contrast The literature indicates that MRI abdomen and pelvis without and with IV contrast may be used in intermediate- risk patients for 1) nodal and distant metastasis staging in addition to 2) assessment of the local extent of primary tumor [109-112]. This can be supported by the fact that a priori risk of nodal disease (most of which are in the pelvis and some up to the retroperitoneum) exceeds 10% [20].

Pretreatment Detection Surveillance and Staging of Prostate Cancer. Fluciclovine PET/MRI Skull Base to Mid-Thigh Fluciclovine PET/MRI is less commonly used than fluciclovine PET/CT but shares similar principles and can be considered in the pretreatment assessment of prostate cancer based on its ability to better detect nodal and distant metastases than CT and bone scan [102,105]. The specificity of fluciclovine PET/CT is high (0.98, 95% CI: 0.88- 1.00) [98], and in a study of 57 patients, it demonstrated a higher sensitivity for detecting nodal metastases (55.3% versus 33.3%) and was able to identify 12.3% (7/57) additional patients with distant metastasis when compared with conventional imaging (bone scan and CT) in patients with intermediate- and high-risk disease [106]. Although no specific study deals with only patients with intermediate-risk disease, it is notable that in a study of 28 patients with high-risk disease, the sensitivity and specificity of fluciclovine PET/MRI for detecting nodal metastases was 40% and 100%, respectively [105]. Also, fluciclovine PET/MRI has been shown to potentially improve characterization of the primary tumor compared with PET/CT [103]. Pretreatment Detection of Prostate Cancer MRI Abdomen and Pelvis Without and With IV Contrast The literature indicates that MRI abdomen and pelvis without and with IV contrast may be used in intermediate- risk patients for 1) nodal and distant metastasis staging in addition to 2) assessment of the local extent of primary tumor [109-112]. This can be supported by the fact that a priori risk of nodal disease (most of which are in the pelvis and some up to the retroperitoneum) exceeds 10% [20].

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Pretreatment Detection Surveillance and Staging of Prostate Cancer

In addition, because a majority of the distant metastases occur (at least in the pretreatment setting) in the axial skeleton and it is rare to harbor isolated bone metastases without simultaneously harboring metastases in the pelvic and lumbosacral vertebral bones, MRI abdomen and pelvis is usually sufficient to detect the presence of bone metastasis at the patient level [113]. MRI Abdomen and Pelvis Without IV Contrast Because the main purpose for imaging the abdomen and pelvis would be to identify nodal and distant metastases, MRI abdomen and pelvis without IV contrast is a viable option as an alternative to that using IV contrast [109-113]. However, it should be recognized that without using IV contrast there is the possibility of less optimal detection of metastases to visceral organs. MRI Whole Body Without IV Contrast Because the main purpose for imaging the whole body would be to identify nodal and distant metastases, MRI whole body without IV contrast is a viable option as an alternative to that using IV contrast [49,96,108-112,114- 117]. However, it should be recognized that without using IV contrast there is the possibility of less optimal detection of metastases to visceral organs. Pretreatment Detection of Prostate Cancer PSMA PET/CT Skull Base to Mid-Thigh The literature indicates PSMA PET/CT is useful in patients with intermediate- and high-risk disease. PSMA PET, which can be used with CT or MRI (PET/CT and PET/MRI, respectively), is one of the newer imaging modalities, which has been primarily investigated in the setting of biochemical recurrence and biochemical failure, where, because of its superior capability to detect recurrent disease, has shown to substantially change management [118].

Pretreatment Detection Surveillance and Staging of Prostate Cancer. In addition, because a majority of the distant metastases occur (at least in the pretreatment setting) in the axial skeleton and it is rare to harbor isolated bone metastases without simultaneously harboring metastases in the pelvic and lumbosacral vertebral bones, MRI abdomen and pelvis is usually sufficient to detect the presence of bone metastasis at the patient level [113]. MRI Abdomen and Pelvis Without IV Contrast Because the main purpose for imaging the abdomen and pelvis would be to identify nodal and distant metastases, MRI abdomen and pelvis without IV contrast is a viable option as an alternative to that using IV contrast [109-113]. However, it should be recognized that without using IV contrast there is the possibility of less optimal detection of metastases to visceral organs. MRI Whole Body Without IV Contrast Because the main purpose for imaging the whole body would be to identify nodal and distant metastases, MRI whole body without IV contrast is a viable option as an alternative to that using IV contrast [49,96,108-112,114- 117]. However, it should be recognized that without using IV contrast there is the possibility of less optimal detection of metastases to visceral organs. Pretreatment Detection of Prostate Cancer PSMA PET/CT Skull Base to Mid-Thigh The literature indicates PSMA PET/CT is useful in patients with intermediate- and high-risk disease. PSMA PET, which can be used with CT or MRI (PET/CT and PET/MRI, respectively), is one of the newer imaging modalities, which has been primarily investigated in the setting of biochemical recurrence and biochemical failure, where, because of its superior capability to detect recurrent disease, has shown to substantially change management [118].

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acrac_69371_17

Pretreatment Detection Surveillance and Staging of Prostate Cancer

Nevertheless, many recent studies have shown its potential to detect metastatic disease in patients with intermediate- and high-risk prostate cancer undergoing pretreatment assessment, and it has recently received approval from the FDA for both recurrent and primary staging settings [117,119-121]. PSMA PET/CT examination has higher diagnostic performance for prostate cancer compared to fluciclovine PET/CT, which was able to identify additional patients with distant metastasis when compared to conventional imaging (bone scan and CT) in patients with intermediate- and high-risk disease. In a study of 130 patients with intermediate- and high-risk patients, PSMA PET demonstrated superior sensitivity and a similar specificity to morphological imaging alone (CT or MRI) [121]: 68.3% and 99.1%, respectively, for PSMA PET and 27.3% and 97.1%, respectively, for morphological imaging. Additionally, PSMA PET, especially when combined with MRI, can potentially improve detection and characterization (eg, assessment of local extent) of the primary tumor, by using different types of PSMA-targeted radiotracers, compared with multiparametric MRI alone or clinical nomograms [19,122,123]. TRUS Prostate TRUS is unlikely to provide useful incremental information in patients with an established diagnosis of intermediate-risk prostate cancer and so it is not beneficial. TRUS-Guided Biopsy Prostate Active surveillance may be beneficial in carefully selected patients with intermediate-risk prostate cancer [109- 111]. In that setting, some form of serial TRUS-guided biopsy would be useful as part of the monitoring regimen. Choline PET/CT Skull Base to Mid-Thigh Although choline PET/CT is primarily used in the recurrent setting, it can also be considered in the pretreatment assessment of prostate cancer based on its ability to better detect nodal and distant metastases than CT and bone scan.

Pretreatment Detection Surveillance and Staging of Prostate Cancer. Nevertheless, many recent studies have shown its potential to detect metastatic disease in patients with intermediate- and high-risk prostate cancer undergoing pretreatment assessment, and it has recently received approval from the FDA for both recurrent and primary staging settings [117,119-121]. PSMA PET/CT examination has higher diagnostic performance for prostate cancer compared to fluciclovine PET/CT, which was able to identify additional patients with distant metastasis when compared to conventional imaging (bone scan and CT) in patients with intermediate- and high-risk disease. In a study of 130 patients with intermediate- and high-risk patients, PSMA PET demonstrated superior sensitivity and a similar specificity to morphological imaging alone (CT or MRI) [121]: 68.3% and 99.1%, respectively, for PSMA PET and 27.3% and 97.1%, respectively, for morphological imaging. Additionally, PSMA PET, especially when combined with MRI, can potentially improve detection and characterization (eg, assessment of local extent) of the primary tumor, by using different types of PSMA-targeted radiotracers, compared with multiparametric MRI alone or clinical nomograms [19,122,123]. TRUS Prostate TRUS is unlikely to provide useful incremental information in patients with an established diagnosis of intermediate-risk prostate cancer and so it is not beneficial. TRUS-Guided Biopsy Prostate Active surveillance may be beneficial in carefully selected patients with intermediate-risk prostate cancer [109- 111]. In that setting, some form of serial TRUS-guided biopsy would be useful as part of the monitoring regimen. Choline PET/CT Skull Base to Mid-Thigh Although choline PET/CT is primarily used in the recurrent setting, it can also be considered in the pretreatment assessment of prostate cancer based on its ability to better detect nodal and distant metastases than CT and bone scan.

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acrac_69371_18

Pretreatment Detection Surveillance and Staging of Prostate Cancer

In patients with intermediate- and high-risk prostate cancer, choline PET/CT has shown to identify more nodal and distant metastatic lesions than conventional imaging [96,98-100]. For example, in a study of 48 patients, choline PET/CT showed a higher sensitivity (46.2% versus 69.2%) with an identical specificity (92.3%) for detecting nodal metastases [99]. In another multicenter study of 269 patients, choline PET/CT was shown to identify more nodal and distant metastatic lesions than conventional imaging, which led to a change in therapeutic indication in approximately 70% of patients [100]. Choline PET/MRI Skull Base to Mid-Thigh Choline PET/MRI is less commonly used than choline PET/CT but can be considered in the pretreatment assessment of prostate cancer based on the same principles that it better detects nodal and distant metastases than CT and bone scan [96,98-100]. For example, in a study of 48 patients with intermediate- and high-risk disease, choline PET/CT showed a higher sensitivity (46.2% versus 69.2%) with an identical specificity (92.3%) for detecting nodal metastases [99]. In a prospective study of 58 patients with high-risk disease, which specifically assessed choline PET/MRI, it was superior to CT and bone scan for detecting distant metastases (100% versus 63.6%, respectively) [101]. Pretreatment Detection of Prostate Cancer CT Abdomen and Pelvis With IV Contrast CT abdomen and pelvis with IV contrast for nodal staging is generally useful in high-risk patients because a priori risk of nodal disease exceeds 10% [20]. CT Abdomen and Pelvis Without and With IV Contrast There is limited evidence to support the use of CT abdomen and pelvis without and with IV contrast because obtaining CT with both techniques does not provide additional benefit in terms of detecting nodal and distant metastases.

Pretreatment Detection Surveillance and Staging of Prostate Cancer. In patients with intermediate- and high-risk prostate cancer, choline PET/CT has shown to identify more nodal and distant metastatic lesions than conventional imaging [96,98-100]. For example, in a study of 48 patients, choline PET/CT showed a higher sensitivity (46.2% versus 69.2%) with an identical specificity (92.3%) for detecting nodal metastases [99]. In another multicenter study of 269 patients, choline PET/CT was shown to identify more nodal and distant metastatic lesions than conventional imaging, which led to a change in therapeutic indication in approximately 70% of patients [100]. Choline PET/MRI Skull Base to Mid-Thigh Choline PET/MRI is less commonly used than choline PET/CT but can be considered in the pretreatment assessment of prostate cancer based on the same principles that it better detects nodal and distant metastases than CT and bone scan [96,98-100]. For example, in a study of 48 patients with intermediate- and high-risk disease, choline PET/CT showed a higher sensitivity (46.2% versus 69.2%) with an identical specificity (92.3%) for detecting nodal metastases [99]. In a prospective study of 58 patients with high-risk disease, which specifically assessed choline PET/MRI, it was superior to CT and bone scan for detecting distant metastases (100% versus 63.6%, respectively) [101]. Pretreatment Detection of Prostate Cancer CT Abdomen and Pelvis With IV Contrast CT abdomen and pelvis with IV contrast for nodal staging is generally useful in high-risk patients because a priori risk of nodal disease exceeds 10% [20]. CT Abdomen and Pelvis Without and With IV Contrast There is limited evidence to support the use of CT abdomen and pelvis without and with IV contrast because obtaining CT with both techniques does not provide additional benefit in terms of detecting nodal and distant metastases.

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acrac_69371_19

Pretreatment Detection Surveillance and Staging of Prostate Cancer

CT Abdomen and Pelvis Without IV Contrast CT abdomen and pelvis without IV contrast for nodal staging is generally useful in high-risk patients because a priori risk of nodal disease exceeds 10% [20]. However, it should be recognized that without using IV contrast there is the possibility of less optimal detection of metastases to visceral organs. CT Chest, Abdomen, and Pelvis With IV Contrast CT chest, abdomen, and pelvis with IV contrast for nodal staging is generally useful in high-risk patients because a priori risk of nodal disease exceeds 10% [20]. CT Chest, Abdomen, and Pelvis Without and With IV Contrast There is limited evidence to support the use of CT chest, abdomen, and pelvis without and with IV contrast because obtaining CT with both techniques does not provide additional benefit in terms of detecting nodal and distant metastases. CT Chest, Abdomen, and Pelvis Without IV Contrast CT chest, abdomen, and pelvis without IV contrast for nodal staging is generally useful in high-risk patients because a priori risk of nodal disease exceeds 10% [20]. However, it should be recognized that without using IV contrast there is the possibility of less optimal detection of metastases to visceral organs. FDG-PET/CT Whole Body Because prostate cancer and metastases from it are generally not FDG-avid unlike most other malignancies, FDG- PET/CT may not be beneficial as part of staging clinically established high-risk prostate cancer. FDG-PET/MRI Skull Base to Mid-Thigh Because prostate cancer and metastases from it are generally not FDG-avid unlike most other malignancies, FDG- PET/MRI may not be beneficial as part of staging clinically established high-risk prostate cancer.

Pretreatment Detection Surveillance and Staging of Prostate Cancer. CT Abdomen and Pelvis Without IV Contrast CT abdomen and pelvis without IV contrast for nodal staging is generally useful in high-risk patients because a priori risk of nodal disease exceeds 10% [20]. However, it should be recognized that without using IV contrast there is the possibility of less optimal detection of metastases to visceral organs. CT Chest, Abdomen, and Pelvis With IV Contrast CT chest, abdomen, and pelvis with IV contrast for nodal staging is generally useful in high-risk patients because a priori risk of nodal disease exceeds 10% [20]. CT Chest, Abdomen, and Pelvis Without and With IV Contrast There is limited evidence to support the use of CT chest, abdomen, and pelvis without and with IV contrast because obtaining CT with both techniques does not provide additional benefit in terms of detecting nodal and distant metastases. CT Chest, Abdomen, and Pelvis Without IV Contrast CT chest, abdomen, and pelvis without IV contrast for nodal staging is generally useful in high-risk patients because a priori risk of nodal disease exceeds 10% [20]. However, it should be recognized that without using IV contrast there is the possibility of less optimal detection of metastases to visceral organs. FDG-PET/CT Whole Body Because prostate cancer and metastases from it are generally not FDG-avid unlike most other malignancies, FDG- PET/CT may not be beneficial as part of staging clinically established high-risk prostate cancer. FDG-PET/MRI Skull Base to Mid-Thigh Because prostate cancer and metastases from it are generally not FDG-avid unlike most other malignancies, FDG- PET/MRI may not be beneficial as part of staging clinically established high-risk prostate cancer.

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acrac_69371_20

Pretreatment Detection Surveillance and Staging of Prostate Cancer

Fluciclovine PET/CT Skull Base to Mid-Thigh Although fluciclovine PET/CT is primarily used in the recurrent setting, it can also be considered in the pretreatment assessment of prostate cancer based on its ability to better detect nodal and distant metastases than CT and bone scan [98,102]. The specificity of fluciclovine PET/CT is high (0.98, 95% CI: 0.88-1.00) [98], and in a study of 57 patients, it demonstrated a higher sensitivity for detecting nodal metastases (55.3% versus 33.3%) and was able to identify 12.3% (7/57) additional patients with distant metastasis when compared with conventional imaging (bone scan and CT) in patients with intermediate- and high-risk disease [106]. Fluciclovine PET/MRI Skull Base to Mid-Thigh Fluciclovine PET/MRI is less commonly used than fluciclovine PET/CT but shares similar principles and can be considered in the pretreatment assessment of prostate cancer based on its ability to better detect nodal and distant metastases than CT and bone scan [102,105]. The specificity of fluciclovine PET/CT is high (0.98, 95% CI: 0.88- 1.00) [98], and in a study of 57 patients, it demonstrated a higher sensitivity for detecting nodal metastases (55.3% versus 33.3%) and was able to identify 12.3% (7/57) additional patients with distant metastasis when compared with conventional imaging (bone scan and CT) in patients with intermediate- and high-risk disease [106]. In a study of 28 patients with high-risk disease who underwent fluciclovine PET/MRI, the sensitivity and specificity for detecting nodal metastases was 40% and 100%, respectively [105]. Pretreatment Detection of Prostate Cancer MRI Abdomen and Pelvis Without and With IV Contrast The literature indicates MRI abdomen and pelvis may be used in high-risk patients for 1) nodal and distant metastasis staging in addition to 2) assessment of the local extent of primary tumor [109-112].

Pretreatment Detection Surveillance and Staging of Prostate Cancer. Fluciclovine PET/CT Skull Base to Mid-Thigh Although fluciclovine PET/CT is primarily used in the recurrent setting, it can also be considered in the pretreatment assessment of prostate cancer based on its ability to better detect nodal and distant metastases than CT and bone scan [98,102]. The specificity of fluciclovine PET/CT is high (0.98, 95% CI: 0.88-1.00) [98], and in a study of 57 patients, it demonstrated a higher sensitivity for detecting nodal metastases (55.3% versus 33.3%) and was able to identify 12.3% (7/57) additional patients with distant metastasis when compared with conventional imaging (bone scan and CT) in patients with intermediate- and high-risk disease [106]. Fluciclovine PET/MRI Skull Base to Mid-Thigh Fluciclovine PET/MRI is less commonly used than fluciclovine PET/CT but shares similar principles and can be considered in the pretreatment assessment of prostate cancer based on its ability to better detect nodal and distant metastases than CT and bone scan [102,105]. The specificity of fluciclovine PET/CT is high (0.98, 95% CI: 0.88- 1.00) [98], and in a study of 57 patients, it demonstrated a higher sensitivity for detecting nodal metastases (55.3% versus 33.3%) and was able to identify 12.3% (7/57) additional patients with distant metastasis when compared with conventional imaging (bone scan and CT) in patients with intermediate- and high-risk disease [106]. In a study of 28 patients with high-risk disease who underwent fluciclovine PET/MRI, the sensitivity and specificity for detecting nodal metastases was 40% and 100%, respectively [105]. Pretreatment Detection of Prostate Cancer MRI Abdomen and Pelvis Without and With IV Contrast The literature indicates MRI abdomen and pelvis may be used in high-risk patients for 1) nodal and distant metastasis staging in addition to 2) assessment of the local extent of primary tumor [109-112].

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Pretreatment Detection Surveillance and Staging of Prostate Cancer

This can be supported by the fact that a priori risk of nodal disease (most of which are in the pelvis and some up to the retroperitoneum) exceeds 10% [20]. In addition, because a majority of the distant metastases occur (at least in the pretreatment setting) in the axial skeleton and it is rare to harbor isolated bone metastases without simultaneously harboring metastases in the pelvic and lumbosacral vertebral bones, MRI abdomen and pelvis is usually sufficient to detect the presence of bone metastasis at the patient level [113]. MRI Abdomen and Pelvis Without IV Contrast Because the main purpose for imaging the abdomen and pelvis would be to identify nodal and distant metastases, MRI abdomen and pelvis without IV contrast is a viable option as an alternative to using IV contrast [20,109-113]. However, it should be recognized that without using IV contrast there is possibility of less optimal detection of metastases to visceral organs. MRI Pelvis Without and With IV Contrast In addition to standard local and nodal staging, multiparametric MRI may be helpful in the management of high- risk prostate cancer by identifying more extensive disease that may merit supplementary extended androgen deprivation therapy, localizing dominant disease for focal therapy, guiding surgical planning, or changing management plan from surgery to radiation [49,114,115]. MRI Pelvis Without IV Contrast In addition to standard local and nodal staging, multiparametric MRI without IV contrast may be a viable option as an alternative to using IV contrast in the management of high-risk prostate cancer [49,114,115]. Although the same principles and controversies regarding the use of IV contrast persists, many of these scenarios are less dependent on the potential advantages of IV contrast. MRI-Targeted Biopsy Prostate Most patients with high-risk disease require definitive therapy, and targeted biopsy is unlikely to significantly alter management.

Pretreatment Detection Surveillance and Staging of Prostate Cancer. This can be supported by the fact that a priori risk of nodal disease (most of which are in the pelvis and some up to the retroperitoneum) exceeds 10% [20]. In addition, because a majority of the distant metastases occur (at least in the pretreatment setting) in the axial skeleton and it is rare to harbor isolated bone metastases without simultaneously harboring metastases in the pelvic and lumbosacral vertebral bones, MRI abdomen and pelvis is usually sufficient to detect the presence of bone metastasis at the patient level [113]. MRI Abdomen and Pelvis Without IV Contrast Because the main purpose for imaging the abdomen and pelvis would be to identify nodal and distant metastases, MRI abdomen and pelvis without IV contrast is a viable option as an alternative to using IV contrast [20,109-113]. However, it should be recognized that without using IV contrast there is possibility of less optimal detection of metastases to visceral organs. MRI Pelvis Without and With IV Contrast In addition to standard local and nodal staging, multiparametric MRI may be helpful in the management of high- risk prostate cancer by identifying more extensive disease that may merit supplementary extended androgen deprivation therapy, localizing dominant disease for focal therapy, guiding surgical planning, or changing management plan from surgery to radiation [49,114,115]. MRI Pelvis Without IV Contrast In addition to standard local and nodal staging, multiparametric MRI without IV contrast may be a viable option as an alternative to using IV contrast in the management of high-risk prostate cancer [49,114,115]. Although the same principles and controversies regarding the use of IV contrast persists, many of these scenarios are less dependent on the potential advantages of IV contrast. MRI-Targeted Biopsy Prostate Most patients with high-risk disease require definitive therapy, and targeted biopsy is unlikely to significantly alter management.

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acrac_69371_22

Pretreatment Detection Surveillance and Staging of Prostate Cancer

MRI Whole Body Without and With IV Contrast The literature indicates that MRI whole body can be used to assess the nodal and distant metastatic state in patients with intermediate- and high-risk prostate cancer prior to treatment [96,108,117]. In a prospective study of 56 intermediate- and high-risk patients, whole body MRI was more accurate than bone scan and similar to choline PET/CT for detecting nodal and distant metastases [96]. In a prospective study of 36 high-risk patients, whole body MRI was concordant with PSMA PET/CT for determining nonregional nodal metastases in 72.2% and for distant metastases in 86.1% of the patients [117]. In addition to standard local, nodal, and distant metastasis staging, multiparametric MRI of the prostate may be added in the whole body MRI protocol, providing additional information to assist management of high-risk prostate cancer by identifying more extensive disease that may merit supplementary extended androgen deprivation therapy, localizing dominant disease for focal therapy, guiding surgical planning, or changing management plan from surgery to radiation [49,114,115]. MRI Whole Body Without IV Contrast Because the main purpose for imaging the whole body would be to identify nodal and distant metastases, MRI whole body without IV contrast is a viable option as an alternative to using IV contrast [49,96,108,114,115,117]. However, it should be recognized that without using IV contrast there is the possibility of less optimal detection of metastases to visceral organs. PSMA PET/CT Skull Base to Mid-Thigh PSMA PET, which can be used either with CT or MRI (PET/CT and PET/MRI, respectively) has shown its potential to detect metastatic disease in patients with high-risk prostate cancer undergoing pretreatment assessment [117,119- 121].

Pretreatment Detection Surveillance and Staging of Prostate Cancer. MRI Whole Body Without and With IV Contrast The literature indicates that MRI whole body can be used to assess the nodal and distant metastatic state in patients with intermediate- and high-risk prostate cancer prior to treatment [96,108,117]. In a prospective study of 56 intermediate- and high-risk patients, whole body MRI was more accurate than bone scan and similar to choline PET/CT for detecting nodal and distant metastases [96]. In a prospective study of 36 high-risk patients, whole body MRI was concordant with PSMA PET/CT for determining nonregional nodal metastases in 72.2% and for distant metastases in 86.1% of the patients [117]. In addition to standard local, nodal, and distant metastasis staging, multiparametric MRI of the prostate may be added in the whole body MRI protocol, providing additional information to assist management of high-risk prostate cancer by identifying more extensive disease that may merit supplementary extended androgen deprivation therapy, localizing dominant disease for focal therapy, guiding surgical planning, or changing management plan from surgery to radiation [49,114,115]. MRI Whole Body Without IV Contrast Because the main purpose for imaging the whole body would be to identify nodal and distant metastases, MRI whole body without IV contrast is a viable option as an alternative to using IV contrast [49,96,108,114,115,117]. However, it should be recognized that without using IV contrast there is the possibility of less optimal detection of metastases to visceral organs. PSMA PET/CT Skull Base to Mid-Thigh PSMA PET, which can be used either with CT or MRI (PET/CT and PET/MRI, respectively) has shown its potential to detect metastatic disease in patients with high-risk prostate cancer undergoing pretreatment assessment [117,119- 121].

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acrac_69451_0

Routine Chest Imaging

Historically, routine chest radiography served as a method of screening a general population for disease. Early use of routine chest imaging was used to identify tuberculosis in asymptomatic individuals for public health and safety measures [2]. However, as the overall rates of undiagnosed tuberculosis have decreased, its usefulness is now being questioned [2]. More recent studies have shown that routine imaging in an otherwise healthy and asymptomatic population has a low diagnostic yield [3,4]. Preprocedural routine imaging has also been used for detection of subclinical disease, such as malignant neoplasms, emphysema, or cardiovascular disease, that could be associated with perioperative complications [2]. Multiple studies have shown that routine imaging studies in the preoperative setting have no significant impact on the decision to operate [5] and usually do not yield information that is not available by clinical history or physical examination [6]. However, there are no randomized control trials to show whether routine chest imaging improves outcomes. This document reviews the use of routine chest imaging performed on adult patients for evaluation on hospital admission, preoperative preparation, and asymptomatic outpatient follow-up and evaluation. Special Imaging Considerations Chest radiography can be performed as a 2-view or a single-view imaging study. A 2-view (posterior-anterior and lateral views) chest radiograph requires that a patient is able to stand and appropriately position their arms to be out of the field of view. Alternatively, a single-view chest radiograph using anterior-posterior technique (also refered to as portable technique) can be performed in a patient who is not ambulatory or unable to tolerate positioning of a posterior-anterior radiograph. However, anterior-posterior/portable technique is associated with lower image quality, distortion of normal structures (eg, magnification of the cardiac silhouette), and higher rates of artifactual findings [7].

Routine Chest Imaging. Historically, routine chest radiography served as a method of screening a general population for disease. Early use of routine chest imaging was used to identify tuberculosis in asymptomatic individuals for public health and safety measures [2]. However, as the overall rates of undiagnosed tuberculosis have decreased, its usefulness is now being questioned [2]. More recent studies have shown that routine imaging in an otherwise healthy and asymptomatic population has a low diagnostic yield [3,4]. Preprocedural routine imaging has also been used for detection of subclinical disease, such as malignant neoplasms, emphysema, or cardiovascular disease, that could be associated with perioperative complications [2]. Multiple studies have shown that routine imaging studies in the preoperative setting have no significant impact on the decision to operate [5] and usually do not yield information that is not available by clinical history or physical examination [6]. However, there are no randomized control trials to show whether routine chest imaging improves outcomes. This document reviews the use of routine chest imaging performed on adult patients for evaluation on hospital admission, preoperative preparation, and asymptomatic outpatient follow-up and evaluation. Special Imaging Considerations Chest radiography can be performed as a 2-view or a single-view imaging study. A 2-view (posterior-anterior and lateral views) chest radiograph requires that a patient is able to stand and appropriately position their arms to be out of the field of view. Alternatively, a single-view chest radiograph using anterior-posterior technique (also refered to as portable technique) can be performed in a patient who is not ambulatory or unable to tolerate positioning of a posterior-anterior radiograph. However, anterior-posterior/portable technique is associated with lower image quality, distortion of normal structures (eg, magnification of the cardiac silhouette), and higher rates of artifactual findings [7].

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acrac_69451_1

Routine Chest Imaging

The American College of Radiology seeks and encourages collaboration with other organizations on the development of the ACR Appropriateness Criteria through representation of such organizations on expert panels. Participation on the expert panel does not necessarily imply endorsement of the final document by individual contributors or their respective organization. Reprint requests to: [email protected] All elements are essential: 1) timing, 2) reconstructions/reformats, and 3) 3-D renderings. Standard CTs with contrast also include timing issues and reconstructions/reformats. Only in CTA, however, is 3-D rendering a required element. This corresponds to the definitions that the CMS has applied to the Current Procedural Terminology codes. OR Discussion of Procedures by Variant Variant 1: Routine chest imaging for hospital admission. No clinical concern for cardiopulmonary disease. Initial Imaging. CT Chest With IV Contrast There is no relevant literature to support the use of CT chest with intravenous (IV) contrast as routine imaging for hospital admission. CT Chest Without and With IV Contrast There is no relevant literature to support the use of CT chest without and with IV contrast as routine imaging for hospital admission. CT Chest Without IV Contrast CT chest is known to have a higher sensitivity than chest radiography for the detection of pulmonary infections and malignancies. Millor et al [9] performed a retrospective review of 6,516 adult patients who underwent a self-referred whole-body CT (including a CT chest without IV contrast), performed in the absence of specific symptoms and no history of malignancy. The authors found that the incidence of abnormal whole-body CT findings increased with age and found a higher rate of abnormal findings in men. Although most findings were benign, there was a 1.47% rate of primary neoplasm detection, the majority of which were found before metastatic spread.

Routine Chest Imaging. The American College of Radiology seeks and encourages collaboration with other organizations on the development of the ACR Appropriateness Criteria through representation of such organizations on expert panels. Participation on the expert panel does not necessarily imply endorsement of the final document by individual contributors or their respective organization. Reprint requests to: [email protected] All elements are essential: 1) timing, 2) reconstructions/reformats, and 3) 3-D renderings. Standard CTs with contrast also include timing issues and reconstructions/reformats. Only in CTA, however, is 3-D rendering a required element. This corresponds to the definitions that the CMS has applied to the Current Procedural Terminology codes. OR Discussion of Procedures by Variant Variant 1: Routine chest imaging for hospital admission. No clinical concern for cardiopulmonary disease. Initial Imaging. CT Chest With IV Contrast There is no relevant literature to support the use of CT chest with intravenous (IV) contrast as routine imaging for hospital admission. CT Chest Without and With IV Contrast There is no relevant literature to support the use of CT chest without and with IV contrast as routine imaging for hospital admission. CT Chest Without IV Contrast CT chest is known to have a higher sensitivity than chest radiography for the detection of pulmonary infections and malignancies. Millor et al [9] performed a retrospective review of 6,516 adult patients who underwent a self-referred whole-body CT (including a CT chest without IV contrast), performed in the absence of specific symptoms and no history of malignancy. The authors found that the incidence of abnormal whole-body CT findings increased with age and found a higher rate of abnormal findings in men. Although most findings were benign, there was a 1.47% rate of primary neoplasm detection, the majority of which were found before metastatic spread.

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Routine Chest Imaging

The authors suggested that the early detection of these abnormalities (eg, before metastatic spread of malignancy) allows for earlier intervention and sometimes curative treatment. A number of incidental and relatively common cardiac abnormalities can be detected on routine CT chest without IV contrast [9,10]. These include pericardial, myocardial, coronary, aortic, and valvular abnormalities. CTA Chest With IV Contrast There is no relevant literature to support the use of CTA chest with IV contrast as routine imaging for hospital admission. CTA Chest Without and With IV Contrast There is no relevant literature to support the use of CTA chest without and with IV contrast as routine imaging for hospital admission. FDG-PET/CT Skull Base to Mid-Thigh There is no relevant literature to support the use of fluorine-18-2-fluoro-2-deoxy-D-glucose (FDG)-PET/CT for routine initial chest imaging on hospital admission in the absence of cardiopulmonary disease. MRI Chest Without and With IV Contrast There is no relevant literature to support the use of MRI chest without and with IV contrast for routine chest imaging on hospital admission in the absence of cardiopulmonary disease. Routine Chest Imaging MRI Chest Without IV Contrast There is no relevant literature to support the use of MRI chest without IV contrast as routine imaging for hospital admission in the absence of cardiopulmonary disease. Radiography Chest Chest radiography is a commonly ordered study on hospital admission. In a retrospective study by Shimoni et al [11] of 238 patient records and interviews with treating physicians, the investigators found that routine admission chest radiography yielded minimal benefit in patients without respiratory symptoms. In addition, routine admission chest radiography was also associated with false-positive findings, leading to inappropriate hospitalization and unnecessary antibiotic therapy.

Routine Chest Imaging. The authors suggested that the early detection of these abnormalities (eg, before metastatic spread of malignancy) allows for earlier intervention and sometimes curative treatment. A number of incidental and relatively common cardiac abnormalities can be detected on routine CT chest without IV contrast [9,10]. These include pericardial, myocardial, coronary, aortic, and valvular abnormalities. CTA Chest With IV Contrast There is no relevant literature to support the use of CTA chest with IV contrast as routine imaging for hospital admission. CTA Chest Without and With IV Contrast There is no relevant literature to support the use of CTA chest without and with IV contrast as routine imaging for hospital admission. FDG-PET/CT Skull Base to Mid-Thigh There is no relevant literature to support the use of fluorine-18-2-fluoro-2-deoxy-D-glucose (FDG)-PET/CT for routine initial chest imaging on hospital admission in the absence of cardiopulmonary disease. MRI Chest Without and With IV Contrast There is no relevant literature to support the use of MRI chest without and with IV contrast for routine chest imaging on hospital admission in the absence of cardiopulmonary disease. Routine Chest Imaging MRI Chest Without IV Contrast There is no relevant literature to support the use of MRI chest without IV contrast as routine imaging for hospital admission in the absence of cardiopulmonary disease. Radiography Chest Chest radiography is a commonly ordered study on hospital admission. In a retrospective study by Shimoni et al [11] of 238 patient records and interviews with treating physicians, the investigators found that routine admission chest radiography yielded minimal benefit in patients without respiratory symptoms. In addition, routine admission chest radiography was also associated with false-positive findings, leading to inappropriate hospitalization and unnecessary antibiotic therapy.

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acrac_69451_3

Routine Chest Imaging

The authors concluded that admission chest radiography was not warranted in patients without respiratory symptoms but could be considered in patients with an uncertain diagnosis who may present atypically, such as older patients, patients who are immunocompromised, or who cannot communicate symptoms with multiple comorbidities and uncertain diagnosis on admission. Malnik et al [12] conducted a retrospective investigation of medical records and found that a very small number of admission chest radiographs altered patient management if there was no clinical indication or abnormal physical examination finding. The authors concluded that a routine admission radiograph only altered management if there was a clinical indication for performance or abnormal physical examination findings in the thorax. Variant 2: Routine preoperative chest imaging for noncardiothoracic surgery. No history of chronic cardiopulmonary disease or cardiothoracic surgery. Initial imaging. CT Chest With IV Contrast Patients undergoing evaluation for abdominal solid organ transplant (eg, liver or kidney) are known to have higher rates of intrathoracic diseases, including coronary artery disease, pleural effusions, pulmonary hypertension, and hepatopulmonary syndrome, which may not be clinically apparent [13,14]. Currently, the American Association for the Study of Liver Diseases recommends screening of liver transplant candidates for hepatopulmonary syndrome. This is initially done by pulse oximetry, although CT chest with IV contrast may be pursued to exclude other causes of pulmonary disease [15]. CT Chest Without and With IV Contrast There is no relevant literature to support the use of CT chest without and with IV contrast for routine preoperative evaluation of patients without cardiopulmonary disease undergoing noncardiothoracic surgery.

Routine Chest Imaging. The authors concluded that admission chest radiography was not warranted in patients without respiratory symptoms but could be considered in patients with an uncertain diagnosis who may present atypically, such as older patients, patients who are immunocompromised, or who cannot communicate symptoms with multiple comorbidities and uncertain diagnosis on admission. Malnik et al [12] conducted a retrospective investigation of medical records and found that a very small number of admission chest radiographs altered patient management if there was no clinical indication or abnormal physical examination finding. The authors concluded that a routine admission radiograph only altered management if there was a clinical indication for performance or abnormal physical examination findings in the thorax. Variant 2: Routine preoperative chest imaging for noncardiothoracic surgery. No history of chronic cardiopulmonary disease or cardiothoracic surgery. Initial imaging. CT Chest With IV Contrast Patients undergoing evaluation for abdominal solid organ transplant (eg, liver or kidney) are known to have higher rates of intrathoracic diseases, including coronary artery disease, pleural effusions, pulmonary hypertension, and hepatopulmonary syndrome, which may not be clinically apparent [13,14]. Currently, the American Association for the Study of Liver Diseases recommends screening of liver transplant candidates for hepatopulmonary syndrome. This is initially done by pulse oximetry, although CT chest with IV contrast may be pursued to exclude other causes of pulmonary disease [15]. CT Chest Without and With IV Contrast There is no relevant literature to support the use of CT chest without and with IV contrast for routine preoperative evaluation of patients without cardiopulmonary disease undergoing noncardiothoracic surgery.

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acrac_69451_4

Routine Chest Imaging

CT Chest Without IV Contrast Patients undergoing evaluation for abdominal solid organ transplant (eg, liver or kidney) are known to have higher rates of intrathoracic diseases, including coronary artery disease, pleural effusions, pulmonary hypertension, and hepatopulmonary syndrome, which may not be clinically apparent [13,14]. Currently, the American Association for the Study of Liver Diseases recommends screening of liver transplant candidates for hepatopulmonary syndrome. This is initially done by pulse oximetry, although CT chest without IV contrast may be pursued to exclude other causes of pulmonary disease [15]. CTA Chest With IV Contrast There is no relevant literature to support the use of CTA chest with IV contrast for routine preoperative evaluation of patients without cardiopulmonary disease undergoing noncardiothoracic surgery. CTA Chest Without and With IV Contrast There is no relevant literature to support the use of CTA chest without and with IV contrast for routine preoperative evaluation of patients without cardiopulmonary disease undergoing noncardiothoracic surgery. FDG-PET/CT Skull Base to Mid-Thigh There is no relevant literature to support the use of FDG-PET/CT for routine preoperative evaluation of patients without cardiopulmonary disease undergoing noncardiothoracic surgery. MRI Chest Without and With IV Contrast There is no relevant literature to support the use of MRI chest without and with IV contrast for routine preoperative evaluation of patients without cardiopulmonary disease undergoing noncardiothoracic surgery. MRI Chest Without IV Contrast There is no relevant literature to support the use of MRI chest without IV contrast for routine preoperative evaluation of patients without cardiopulmonary disease undergoing noncardiothoracic surgery. Routine Chest Imaging Radiography Chest Multiple guidelines for preoperative chest radiography have been published, largely advocating against the use of routine preoperative chest radiographs for elective surgery [16].

Routine Chest Imaging. CT Chest Without IV Contrast Patients undergoing evaluation for abdominal solid organ transplant (eg, liver or kidney) are known to have higher rates of intrathoracic diseases, including coronary artery disease, pleural effusions, pulmonary hypertension, and hepatopulmonary syndrome, which may not be clinically apparent [13,14]. Currently, the American Association for the Study of Liver Diseases recommends screening of liver transplant candidates for hepatopulmonary syndrome. This is initially done by pulse oximetry, although CT chest without IV contrast may be pursued to exclude other causes of pulmonary disease [15]. CTA Chest With IV Contrast There is no relevant literature to support the use of CTA chest with IV contrast for routine preoperative evaluation of patients without cardiopulmonary disease undergoing noncardiothoracic surgery. CTA Chest Without and With IV Contrast There is no relevant literature to support the use of CTA chest without and with IV contrast for routine preoperative evaluation of patients without cardiopulmonary disease undergoing noncardiothoracic surgery. FDG-PET/CT Skull Base to Mid-Thigh There is no relevant literature to support the use of FDG-PET/CT for routine preoperative evaluation of patients without cardiopulmonary disease undergoing noncardiothoracic surgery. MRI Chest Without and With IV Contrast There is no relevant literature to support the use of MRI chest without and with IV contrast for routine preoperative evaluation of patients without cardiopulmonary disease undergoing noncardiothoracic surgery. MRI Chest Without IV Contrast There is no relevant literature to support the use of MRI chest without IV contrast for routine preoperative evaluation of patients without cardiopulmonary disease undergoing noncardiothoracic surgery. Routine Chest Imaging Radiography Chest Multiple guidelines for preoperative chest radiography have been published, largely advocating against the use of routine preoperative chest radiographs for elective surgery [16].

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Routine Chest Imaging

This is based on multiple studies that have shown minimal benefit from the routine use of chest radiography before surgery. Joo et al [17] conducted a systematic literature review to investigate the value of screening chest radiographs before surgery. They found that the diagnostic yield of preoperative chest radiographs in patients <50 years of age is low and are generally not recommended in patients <70 years of age. Most radiologic abnormalities found on preoperative imaging were chronic diseases and did not affect management or outcome [17]. A large retrospective study in 1983 found that preoperative chest radiographs in low-risk patients were unnecessary with only 0.3% of chest radiographs finding a relevant finding [6]; furthermore, these abnormalities were not associated with any perioperative complications or need for additional interventions. However, radiographic abnormalities were more common in patients with known risk factors based on clinical history and examination. The authors contended that clinical evaluation could appropriately predict which patients should undergo preoperative chest radiography and argued against the use of chest radiography for routine preoperative evaluation [6]. A meta-analysis by Archer et al [18] found that unsuspected radiologic findings on routine preoperative chest radiography were rare, occurring in only 1.3% of cases; these rare findings resulted in a change in management in only 0.1% of cases. Gagner et al [19] performed a retrospective review of 1,000 patients who underwent a preoperative chest radiograph and found that 7.4% of studies were abnormal. Abnormal chest radiographs were more common in older individuals than in younger individuals (30% of patients >50 years of age versus 3% in patients <50 years of age), and there were no changes in clinical outcomes due to chest radiographic findings.

Routine Chest Imaging. This is based on multiple studies that have shown minimal benefit from the routine use of chest radiography before surgery. Joo et al [17] conducted a systematic literature review to investigate the value of screening chest radiographs before surgery. They found that the diagnostic yield of preoperative chest radiographs in patients <50 years of age is low and are generally not recommended in patients <70 years of age. Most radiologic abnormalities found on preoperative imaging were chronic diseases and did not affect management or outcome [17]. A large retrospective study in 1983 found that preoperative chest radiographs in low-risk patients were unnecessary with only 0.3% of chest radiographs finding a relevant finding [6]; furthermore, these abnormalities were not associated with any perioperative complications or need for additional interventions. However, radiographic abnormalities were more common in patients with known risk factors based on clinical history and examination. The authors contended that clinical evaluation could appropriately predict which patients should undergo preoperative chest radiography and argued against the use of chest radiography for routine preoperative evaluation [6]. A meta-analysis by Archer et al [18] found that unsuspected radiologic findings on routine preoperative chest radiography were rare, occurring in only 1.3% of cases; these rare findings resulted in a change in management in only 0.1% of cases. Gagner et al [19] performed a retrospective review of 1,000 patients who underwent a preoperative chest radiograph and found that 7.4% of studies were abnormal. Abnormal chest radiographs were more common in older individuals than in younger individuals (30% of patients >50 years of age versus 3% in patients <50 years of age), and there were no changes in clinical outcomes due to chest radiographic findings.

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acrac_69451_6

Routine Chest Imaging

A large, multicenter study found that preoperative radiographs performed in patients undergoing noncardiothoracic surgery rarely influenced the decision to undergo surgery [5]; in fact, 25.7% of cases proceeded to surgery before the radiology report was even available [5]. The authors also found wide variability in the use of preoperative chest radiography between different surgical departments, despite clinical risk factors for cardiopulmonary disease. Patients undergoing evaluation for abdominal solid organ transplant (eg, liver or kidney) are known to have higher rates of intrathoracic diseases, including coronary artery disease, pleural effusions, pulmonary hypertension, and hepatopulmonary syndrome, which may not be clinically apparent [13,14]. In a study of 341 patients being evaluated for liver transplantation, Bozbas et al [20] determined that 48% of patients had an abnormal chest radiograph. Other studies have shown that increasing severity of liver disease correlates to the degree of abnormality on chest radiography [14]. Currently, the American Association for the Study of Liver Diseases recommends screening of liver transplant candidates for hepatopulmonary syndrome. This is initially done by pulse oximetry, although chest radiography may be pursued to exclude other causes of pulmonary disease [15]. Variant 3: Routine preoperative chest imaging for noncardiothoracic surgery. History of chronic cardiopulmonary disease or cardiothoracic surgery. Initial imaging. CT Chest With IV Contrast Patients undergoing evaluation for abdominal solid organ transplant (eg, liver or kidney) are known to have higher rates of intrathoracic diseases, including coronary artery disease, pleural effusions, pulmonary hypertension, and hepatopulmonary syndrome, which may not be clinically apparent [13,14]. Currently, the American Association for the Study of Liver Diseases recommends screening of liver transplant candidates for hepatopulmonary syndrome.

Routine Chest Imaging. A large, multicenter study found that preoperative radiographs performed in patients undergoing noncardiothoracic surgery rarely influenced the decision to undergo surgery [5]; in fact, 25.7% of cases proceeded to surgery before the radiology report was even available [5]. The authors also found wide variability in the use of preoperative chest radiography between different surgical departments, despite clinical risk factors for cardiopulmonary disease. Patients undergoing evaluation for abdominal solid organ transplant (eg, liver or kidney) are known to have higher rates of intrathoracic diseases, including coronary artery disease, pleural effusions, pulmonary hypertension, and hepatopulmonary syndrome, which may not be clinically apparent [13,14]. In a study of 341 patients being evaluated for liver transplantation, Bozbas et al [20] determined that 48% of patients had an abnormal chest radiograph. Other studies have shown that increasing severity of liver disease correlates to the degree of abnormality on chest radiography [14]. Currently, the American Association for the Study of Liver Diseases recommends screening of liver transplant candidates for hepatopulmonary syndrome. This is initially done by pulse oximetry, although chest radiography may be pursued to exclude other causes of pulmonary disease [15]. Variant 3: Routine preoperative chest imaging for noncardiothoracic surgery. History of chronic cardiopulmonary disease or cardiothoracic surgery. Initial imaging. CT Chest With IV Contrast Patients undergoing evaluation for abdominal solid organ transplant (eg, liver or kidney) are known to have higher rates of intrathoracic diseases, including coronary artery disease, pleural effusions, pulmonary hypertension, and hepatopulmonary syndrome, which may not be clinically apparent [13,14]. Currently, the American Association for the Study of Liver Diseases recommends screening of liver transplant candidates for hepatopulmonary syndrome.

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Routine Chest Imaging

This is initially done by pulse oximetry, although CT chest with IV contrast may be pursued to exclude other causes of pulmonary disease [15]. CT Chest Without and With IV Contrast There is no relevant literature to support the use of CT chest without and with IV contrast for routine preoperative evaluation of patients with chronic cardiopulmonary disease undergoing noncardiothoracic surgery. CT Chest Without IV Contrast Patients undergoing evaluation for abdominal solid organ transplant (eg, liver or kidney) are known to have higher rates of intrathoracic diseases, including coronary artery disease, pleural effusions, pulmonary hypertension, and hepatopulmonary syndrome, which may not be clinically apparent [13,14]. Currently, the American Association for the Study of Liver Diseases recommends screening of liver transplant candidates for hepatopulmonary syndrome. Routine Chest Imaging This is initially done by pulse oximetry, although CT chest without IV contrast may be pursued to exclude other causes of pulmonary disease [15]. CTA Chest With IV Contrast There is no relevant literature to support the use of CTA chest with IV contrast for routine preoperative evaluation of patients with chronic cardiopulmonary disease undergoing noncardiothoracic surgery. CTA Chest Without and With IV Contrast There is no relevant literature to support the use of CTA chest without and with IV contrast for routine preoperative evaluation of patients with chronic cardiopulmonary disease undergoing noncardiothoracic surgery. FDG-PET/CT Skull Base to Mid-Thigh There is no relevant literature to support the use of FDG-PET/CT for routine preoperative evaluation of patients with chronic cardiopulmonary disease undergoing noncardiothoracic surgery. MRI Chest Without and With IV Contrast There is no relevant literature to support the use of MRI chest without and with IV contrast for routine preoperative evaluation of patients with chronic cardiopulmonary disease undergoing noncardiothoracic surgery.

Routine Chest Imaging. This is initially done by pulse oximetry, although CT chest with IV contrast may be pursued to exclude other causes of pulmonary disease [15]. CT Chest Without and With IV Contrast There is no relevant literature to support the use of CT chest without and with IV contrast for routine preoperative evaluation of patients with chronic cardiopulmonary disease undergoing noncardiothoracic surgery. CT Chest Without IV Contrast Patients undergoing evaluation for abdominal solid organ transplant (eg, liver or kidney) are known to have higher rates of intrathoracic diseases, including coronary artery disease, pleural effusions, pulmonary hypertension, and hepatopulmonary syndrome, which may not be clinically apparent [13,14]. Currently, the American Association for the Study of Liver Diseases recommends screening of liver transplant candidates for hepatopulmonary syndrome. Routine Chest Imaging This is initially done by pulse oximetry, although CT chest without IV contrast may be pursued to exclude other causes of pulmonary disease [15]. CTA Chest With IV Contrast There is no relevant literature to support the use of CTA chest with IV contrast for routine preoperative evaluation of patients with chronic cardiopulmonary disease undergoing noncardiothoracic surgery. CTA Chest Without and With IV Contrast There is no relevant literature to support the use of CTA chest without and with IV contrast for routine preoperative evaluation of patients with chronic cardiopulmonary disease undergoing noncardiothoracic surgery. FDG-PET/CT Skull Base to Mid-Thigh There is no relevant literature to support the use of FDG-PET/CT for routine preoperative evaluation of patients with chronic cardiopulmonary disease undergoing noncardiothoracic surgery. MRI Chest Without and With IV Contrast There is no relevant literature to support the use of MRI chest without and with IV contrast for routine preoperative evaluation of patients with chronic cardiopulmonary disease undergoing noncardiothoracic surgery.

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acrac_69451_8

Routine Chest Imaging

MRI Chest Without IV Contrast There is no relevant literature to support the use of MRI chest without IV contrast for routine preoperative evaluation of patients with chronic cardiopulmonary disease undergoing noncardiothoracic surgery. Radiography Chest In a retrospective cohort study of patients with known cardiothoracic disease, abnormal chest radiographic findings were a common finding [21]. However, a review of preoperative chest radiographs in a general population (performed before a variety of different types of surgeries) found that only 5% of studies had an impact on anesthetic management [22]. The authors suggested that discontinuing the use of routine preoperative chest radiographs did not result in any adverse effects on patient care. A study of 240 patients with known vascular disease investigated the role of preprocedural chest radiographs before peripheral or coronary angiography. Although nearly half of preprocedural chest radiographs had at least one abnormality, no procedures were postponed or canceled because of the radiographic findings [23]. Given these findings, multiple societal guidelines have been published, largely recommending against the use of routine preoperative chest radiography for patients with known cardiovascular disease. The European Society of Anaesthesia does not recommend routine preoperative chest radiography for elective noncardiac surgery because it rarely changes perioperative course [24]. A practice advisory by the American Society of Anesthesiologists Task Force acknowledged that radiographic abnormalities are higher in older patients and those with stable cardiothoracic disease but did not recommend routine chest radiography in the preanesthesia evaluation of these patients [25]. Evidence generally suggests that most preoperative abnormalities may be predicted by clinical evaluation, although chest radiography may be helpful in patients with known chronic disease or patients >50 years of age [26].

Routine Chest Imaging. MRI Chest Without IV Contrast There is no relevant literature to support the use of MRI chest without IV contrast for routine preoperative evaluation of patients with chronic cardiopulmonary disease undergoing noncardiothoracic surgery. Radiography Chest In a retrospective cohort study of patients with known cardiothoracic disease, abnormal chest radiographic findings were a common finding [21]. However, a review of preoperative chest radiographs in a general population (performed before a variety of different types of surgeries) found that only 5% of studies had an impact on anesthetic management [22]. The authors suggested that discontinuing the use of routine preoperative chest radiographs did not result in any adverse effects on patient care. A study of 240 patients with known vascular disease investigated the role of preprocedural chest radiographs before peripheral or coronary angiography. Although nearly half of preprocedural chest radiographs had at least one abnormality, no procedures were postponed or canceled because of the radiographic findings [23]. Given these findings, multiple societal guidelines have been published, largely recommending against the use of routine preoperative chest radiography for patients with known cardiovascular disease. The European Society of Anaesthesia does not recommend routine preoperative chest radiography for elective noncardiac surgery because it rarely changes perioperative course [24]. A practice advisory by the American Society of Anesthesiologists Task Force acknowledged that radiographic abnormalities are higher in older patients and those with stable cardiothoracic disease but did not recommend routine chest radiography in the preanesthesia evaluation of these patients [25]. Evidence generally suggests that most preoperative abnormalities may be predicted by clinical evaluation, although chest radiography may be helpful in patients with known chronic disease or patients >50 years of age [26].

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Routine Chest Imaging

One exception is patients with cardiac implantable electronic devices (implanted cardioverter-defibrillators and pacemakers), in whom certain procedures and surgical instruments can be associated with electromagnetic interference (eg, extracorporeal shock wave lithotripsy, radiofrequency ablation, electrocautery) [27]. In the setting of known cardiovascular disease and implanted electronic device, preoperative/preprocedural chest radiograph may be useful for identification of the device type as well as identification of device location [27-29] because these device-related factors may direct selection of surgical instruments or surgical approach. Patients undergoing evaluation for abdominal solid organ transplant (eg, liver or kidney) are known to have higher rates of intrathoracic diseases including coronary artery disease, pleural effusions, pulmonary hypertension, and hepatopulmonary syndrome, which may not be clinically apparent [13,14]. In a study of 341 patients being evaluated for liver transplantation, Bozbas et al [20] determined that 48% of patients had an abnormal chest radiograph. Other studies have shown that increasing severity of liver disease correlates to degree of abnormality on chest radiography [14]. Currently, the American Association for the Study of Liver Diseases recommends screening of liver transplant candidates for hepatopulmonary syndrome. This is initially done by pulse oximetry, although chest radiography may be pursued to exclude other causes of pulmonary disease [15]. Routine Chest Imaging Variant 4: Routine chest imaging. History of chronic cardiopulmonary disease with stable clinical findings. Surveillance chest imaging. CT Chest With IV Contrast There is no relevant literature to support the use of CT chest with IV contrast for surveillance of patients with unspecified chronic, stable cardiopulmonary disease.

Routine Chest Imaging. One exception is patients with cardiac implantable electronic devices (implanted cardioverter-defibrillators and pacemakers), in whom certain procedures and surgical instruments can be associated with electromagnetic interference (eg, extracorporeal shock wave lithotripsy, radiofrequency ablation, electrocautery) [27]. In the setting of known cardiovascular disease and implanted electronic device, preoperative/preprocedural chest radiograph may be useful for identification of the device type as well as identification of device location [27-29] because these device-related factors may direct selection of surgical instruments or surgical approach. Patients undergoing evaluation for abdominal solid organ transplant (eg, liver or kidney) are known to have higher rates of intrathoracic diseases including coronary artery disease, pleural effusions, pulmonary hypertension, and hepatopulmonary syndrome, which may not be clinically apparent [13,14]. In a study of 341 patients being evaluated for liver transplantation, Bozbas et al [20] determined that 48% of patients had an abnormal chest radiograph. Other studies have shown that increasing severity of liver disease correlates to degree of abnormality on chest radiography [14]. Currently, the American Association for the Study of Liver Diseases recommends screening of liver transplant candidates for hepatopulmonary syndrome. This is initially done by pulse oximetry, although chest radiography may be pursued to exclude other causes of pulmonary disease [15]. Routine Chest Imaging Variant 4: Routine chest imaging. History of chronic cardiopulmonary disease with stable clinical findings. Surveillance chest imaging. CT Chest With IV Contrast There is no relevant literature to support the use of CT chest with IV contrast for surveillance of patients with unspecified chronic, stable cardiopulmonary disease.

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acrac_3099187_0

Imaging of Possible Tuberculosis

Introduction/Background Pulmonary tuberculosis (TB) predominantly results from the transmission of aerosolized mycobacterium TB to susceptible hosts [1]. In the vast majority of cases, this results in subclinical disease with the immune system isolating the organism. In this setting, a person has latent TB and does not pose a risk to the community at large. The development of active infection within 1 year following exposure is termed primary TB and is classically described as a lobar pneumonia and/or mediastinal and hilar adenopathy. This pattern is most often seen in children and severely immunocompromised individuals. If active infection develops later than 1 year after initial exposure, it is considered to be reactivation TB, often presenting with apical posterior upper-lobe or superior- segment lower-lobe fibrocavitary disease and endobronchial spread through the airways. With modern molecular techniques it has been shown that radiographic patterns of primary and reactivation TB overlap, and thus the preferred terminology for TB infection is active TB [2]. The important public health issue is that both primary and reactivation TB present a risk of exposing the general population to TB infection. A high level of suspicion should be maintained in immunocompromised hosts, particularly those with AIDS, as imaging manifestations may not fit a classic primary or reactivation pattern; instead, these patients may present with mediastinal lymphadenopathy alone or a deceptively normal chest radiograph. Overview of Imaging Modalities Chest radiograph The chest radiograph is usually the first study performed in patients suspected of having TB. Although frontal and lateral radiographs are often performed in this setting, it has been shown that the lateral radiograph does not improve the detection of findings related to TB [3].

Imaging of Possible Tuberculosis. Introduction/Background Pulmonary tuberculosis (TB) predominantly results from the transmission of aerosolized mycobacterium TB to susceptible hosts [1]. In the vast majority of cases, this results in subclinical disease with the immune system isolating the organism. In this setting, a person has latent TB and does not pose a risk to the community at large. The development of active infection within 1 year following exposure is termed primary TB and is classically described as a lobar pneumonia and/or mediastinal and hilar adenopathy. This pattern is most often seen in children and severely immunocompromised individuals. If active infection develops later than 1 year after initial exposure, it is considered to be reactivation TB, often presenting with apical posterior upper-lobe or superior- segment lower-lobe fibrocavitary disease and endobronchial spread through the airways. With modern molecular techniques it has been shown that radiographic patterns of primary and reactivation TB overlap, and thus the preferred terminology for TB infection is active TB [2]. The important public health issue is that both primary and reactivation TB present a risk of exposing the general population to TB infection. A high level of suspicion should be maintained in immunocompromised hosts, particularly those with AIDS, as imaging manifestations may not fit a classic primary or reactivation pattern; instead, these patients may present with mediastinal lymphadenopathy alone or a deceptively normal chest radiograph. Overview of Imaging Modalities Chest radiograph The chest radiograph is usually the first study performed in patients suspected of having TB. Although frontal and lateral radiographs are often performed in this setting, it has been shown that the lateral radiograph does not improve the detection of findings related to TB [3].

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Imaging of Possible Tuberculosis

In those with signs or symptoms of disease, the radiographic pattern of upper-lobe or superior-segment lower-lobe fibrocavitary disease in the appropriate clinical setting is sufficient to warrant respiratory isolation and sputum culture for definitive diagnosis. Using radiographs in combination with clinical evaluation results in a high sensitivity for the diagnosis but a relatively low specificity for both latent [4] and active TB [5]. In addition, radiographs may reveal ancillary findings of TB such as pleural effusion or spondylitis. For immunocompromised hosts, particularly those with a low CD4 count, computed tomography (CT) should be considered. 1Principal Author and Panel Chair, Medical University of South Carolina, Charleston, South Carolina. 2Panel Vice-chair, National Jewish Health, Denver, Colorado. 3Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts. 4University of Texas MD Anderson Cancer Center, Houston, Texas. 5Mayo Clinic, Rochester, Minnesota. 6Mayo Clinic, Phoenix, Arizona. 7Vanderbilt University Medical Center, Nashville, Tennessee, American College of Chest Physicians. 8Mayo Clinic, Jacksonville, Florida. 9Columbia University Medical Center New York and Temple University Health System, Philadelphia, Pennsylvania. 10Specialty Chair, University of Florida College of Medicine, Gainesville, Florida. The American College of Radiology seeks and encourages collaboration with other organizations on the development of the ACR Appropriateness Criteria through society representation on expert panels. Participation by representatives from collaborating societies on the expert panel does not necessarily imply individual or society endorsement of the final document. Reprint requests to: [email protected] Imaging of Possible Tuberculosis Magnetic resonance imaging Only 1 study has been performed evaluating magnetic resonance imaging (MRI) for suspected TB.

Imaging of Possible Tuberculosis. In those with signs or symptoms of disease, the radiographic pattern of upper-lobe or superior-segment lower-lobe fibrocavitary disease in the appropriate clinical setting is sufficient to warrant respiratory isolation and sputum culture for definitive diagnosis. Using radiographs in combination with clinical evaluation results in a high sensitivity for the diagnosis but a relatively low specificity for both latent [4] and active TB [5]. In addition, radiographs may reveal ancillary findings of TB such as pleural effusion or spondylitis. For immunocompromised hosts, particularly those with a low CD4 count, computed tomography (CT) should be considered. 1Principal Author and Panel Chair, Medical University of South Carolina, Charleston, South Carolina. 2Panel Vice-chair, National Jewish Health, Denver, Colorado. 3Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts. 4University of Texas MD Anderson Cancer Center, Houston, Texas. 5Mayo Clinic, Rochester, Minnesota. 6Mayo Clinic, Phoenix, Arizona. 7Vanderbilt University Medical Center, Nashville, Tennessee, American College of Chest Physicians. 8Mayo Clinic, Jacksonville, Florida. 9Columbia University Medical Center New York and Temple University Health System, Philadelphia, Pennsylvania. 10Specialty Chair, University of Florida College of Medicine, Gainesville, Florida. The American College of Radiology seeks and encourages collaboration with other organizations on the development of the ACR Appropriateness Criteria through society representation on expert panels. Participation by representatives from collaborating societies on the expert panel does not necessarily imply individual or society endorsement of the final document. Reprint requests to: [email protected] Imaging of Possible Tuberculosis Magnetic resonance imaging Only 1 study has been performed evaluating magnetic resonance imaging (MRI) for suspected TB.

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acrac_3099187_2

Imaging of Possible Tuberculosis

In this study the accuracy of MRI was similar to CT in describing findings related to culture-positive patients [12]. Inferential data regarding the value of MRI can also be derived from its role in cystic fibrosis and the observation in other settings that MRI correlates well with CT for parenchymal findings including bronchiectasis, cavitation, and tree- in-bud nodules [13]. Although MRI is technically feasible and described in the literature, MRI has not been specifically evaluated as a primary imaging modality for patients with suspected or proven TB. Nuclear scintigraphy Several nuclear radiopharmaceuticals have been employed for the purpose of evaluating possible TB, particularly for differentiating active from inactive tuberculomas and distinguishing tuberculomas from neoplasms. In small studies, Tc-99m methoxyisobutylisonitrile has shown higher activity over background in active tuberculomas compared with inactive tuberculomas [14,15]. Similarly, metabolic activity measured by fluorine-18-2-fluoro-2- deoxy-D-glucose positron emission tomography (FDG-PET) is higher in active tuberculomas. Dual-time-point FDG-PET imaging (1 and 2 hours postinjection) can also help differentiate active tuberculomas from neoplasms, owing to the longer retention of FDG in benign lesions [16]. Gallium 67 has been used to follow patients for disease activity and correlates with the number of organisms on sputum smears [17]. Evidence for the use of nuclear imaging to diagnose active TB is limited to either small single-site studies or several small studies, and the impact on clinical practice and patient care at this time is minimal. Discussion of the Imaging Modalities by Variant Variant 1: Suspect active tuberculosis. The initial suspicion of active TB should be made based on clinical symptoms and demographics.

Imaging of Possible Tuberculosis. In this study the accuracy of MRI was similar to CT in describing findings related to culture-positive patients [12]. Inferential data regarding the value of MRI can also be derived from its role in cystic fibrosis and the observation in other settings that MRI correlates well with CT for parenchymal findings including bronchiectasis, cavitation, and tree- in-bud nodules [13]. Although MRI is technically feasible and described in the literature, MRI has not been specifically evaluated as a primary imaging modality for patients with suspected or proven TB. Nuclear scintigraphy Several nuclear radiopharmaceuticals have been employed for the purpose of evaluating possible TB, particularly for differentiating active from inactive tuberculomas and distinguishing tuberculomas from neoplasms. In small studies, Tc-99m methoxyisobutylisonitrile has shown higher activity over background in active tuberculomas compared with inactive tuberculomas [14,15]. Similarly, metabolic activity measured by fluorine-18-2-fluoro-2- deoxy-D-glucose positron emission tomography (FDG-PET) is higher in active tuberculomas. Dual-time-point FDG-PET imaging (1 and 2 hours postinjection) can also help differentiate active tuberculomas from neoplasms, owing to the longer retention of FDG in benign lesions [16]. Gallium 67 has been used to follow patients for disease activity and correlates with the number of organisms on sputum smears [17]. Evidence for the use of nuclear imaging to diagnose active TB is limited to either small single-site studies or several small studies, and the impact on clinical practice and patient care at this time is minimal. Discussion of the Imaging Modalities by Variant Variant 1: Suspect active tuberculosis. The initial suspicion of active TB should be made based on clinical symptoms and demographics.

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acrac_3099187_3

Imaging of Possible Tuberculosis

Those at particular risk include those in close contact with patients having active TB, spending time in a TB-endemic country, or working/spending time in sites where TB is more prevalent, such as prisons, homeless shelters, and long-term care facilities. Those who are immunocompromised are at particular risk. Included in this category are also individuals with a newly positive purified protein derivative (PPD) skin test or a positive interferon-gamma release assay (IGRA) and who have symptoms that could be related to active TB. Clinical symptoms of active TB may include unexplained weight loss, night sweats, fever, prolonged cough, hemoptysis, and fatigue. Chest radiography Identified individuals should undergo chest radiography as the initial test. Chest radiographs have been shown to have a high sensitivity for detecting manifestations of active TB [5]. Chest radiography has a high sensitivity but relatively poor specificity owing to the overlap of findings with nontuberculous pulmonary infection. The yield of chest radiographs in high-risk patients ranges from 1% to 7%, although it is not clear how many of these cases would have been suspected based on clinical symptoms alone [18,19]. In particular, lobar pneumonia with associated hilar and/or mediastinal adenopathy or cavitary air space disease involving the apical posterior segments of the upper lobe or superior segment of the lower lobe should raise particular concern [20]. When a chest radiograph confirms the clinical suspicion of active TB, it is sufficient to warrant respiratory isolation pending sputum cultures. However, in patients who are immunocompromised, particularly those with AIDS and very low CD4 counts, chest radiographs may be deceptively normal. Magnetic resonance imaging MRI is a reasonable consideration for use in select patients for whom there is a desire to avoid ionizing radiation. Variant 2: Newly positive PPD or IGRA OR positive PPD or IGRA with unknown prior status. No clinical symptoms.

Imaging of Possible Tuberculosis. Those at particular risk include those in close contact with patients having active TB, spending time in a TB-endemic country, or working/spending time in sites where TB is more prevalent, such as prisons, homeless shelters, and long-term care facilities. Those who are immunocompromised are at particular risk. Included in this category are also individuals with a newly positive purified protein derivative (PPD) skin test or a positive interferon-gamma release assay (IGRA) and who have symptoms that could be related to active TB. Clinical symptoms of active TB may include unexplained weight loss, night sweats, fever, prolonged cough, hemoptysis, and fatigue. Chest radiography Identified individuals should undergo chest radiography as the initial test. Chest radiographs have been shown to have a high sensitivity for detecting manifestations of active TB [5]. Chest radiography has a high sensitivity but relatively poor specificity owing to the overlap of findings with nontuberculous pulmonary infection. The yield of chest radiographs in high-risk patients ranges from 1% to 7%, although it is not clear how many of these cases would have been suspected based on clinical symptoms alone [18,19]. In particular, lobar pneumonia with associated hilar and/or mediastinal adenopathy or cavitary air space disease involving the apical posterior segments of the upper lobe or superior segment of the lower lobe should raise particular concern [20]. When a chest radiograph confirms the clinical suspicion of active TB, it is sufficient to warrant respiratory isolation pending sputum cultures. However, in patients who are immunocompromised, particularly those with AIDS and very low CD4 counts, chest radiographs may be deceptively normal. Magnetic resonance imaging MRI is a reasonable consideration for use in select patients for whom there is a desire to avoid ionizing radiation. Variant 2: Newly positive PPD or IGRA OR positive PPD or IGRA with unknown prior status. No clinical symptoms.

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acrac_3099187_4

Imaging of Possible Tuberculosis

Chest radiography One key principal of PPD testing is application in those at high risk for developing latent TB infection. This may include those who work in settings where contact with active TB is possible and those coming from regions where Imaging of Possible Tuberculosis TB is endemic. Although screening of low-risk individuals is discouraged, it is recommended for those whose future activity will place them at high risk for exposure or reactivation. The rationale behind performing chest radiography following a positive PPD is to distinguish latent TB from active TB, as these are managed differently. However, in patients without clinical symptoms the yield of radiographs for active TB (that would change management) is negligible [21]. Furthermore, parenchymal findings of latent TB are relatively poor predictors of future reactivation. If a chest radiograph is performed, a frontal view is sufficient [3]. Computed tomography CT should be reserved for the rare case in which a chest radiograph may be equivocal for active TB and cases for which knowledge of latent TB abnormalities may inform future care, such as patients undergoing solid organ transplantation and biologic therapy for rheumatologic disease [4,11]. Magnetic resonance imaging Like CT, there is a very limited role for MRI, although it may be considered when cross-sectional imaging is deemed necessary in a patient for whom there is a desire to avoid ionizing radiation. Variant 3: PPD not available. Placement in group home or skilled nursing facility. No clinical symptoms. Chest radiography Low-risk screening also frequently occurs in patients being transferred to correctional institutions, group homes, and skilled nursing facilities. Because of time constraints related to placing and interpreting a PPD, chest radiography has emerged as a surrogate measure.

Imaging of Possible Tuberculosis. Chest radiography One key principal of PPD testing is application in those at high risk for developing latent TB infection. This may include those who work in settings where contact with active TB is possible and those coming from regions where Imaging of Possible Tuberculosis TB is endemic. Although screening of low-risk individuals is discouraged, it is recommended for those whose future activity will place them at high risk for exposure or reactivation. The rationale behind performing chest radiography following a positive PPD is to distinguish latent TB from active TB, as these are managed differently. However, in patients without clinical symptoms the yield of radiographs for active TB (that would change management) is negligible [21]. Furthermore, parenchymal findings of latent TB are relatively poor predictors of future reactivation. If a chest radiograph is performed, a frontal view is sufficient [3]. Computed tomography CT should be reserved for the rare case in which a chest radiograph may be equivocal for active TB and cases for which knowledge of latent TB abnormalities may inform future care, such as patients undergoing solid organ transplantation and biologic therapy for rheumatologic disease [4,11]. Magnetic resonance imaging Like CT, there is a very limited role for MRI, although it may be considered when cross-sectional imaging is deemed necessary in a patient for whom there is a desire to avoid ionizing radiation. Variant 3: PPD not available. Placement in group home or skilled nursing facility. No clinical symptoms. Chest radiography Low-risk screening also frequently occurs in patients being transferred to correctional institutions, group homes, and skilled nursing facilities. Because of time constraints related to placing and interpreting a PPD, chest radiography has emerged as a surrogate measure.

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Imaging of Possible Tuberculosis

A meta-analysis of homeless populations suggests that using chest radiography as a screening measure is sufficient and can lead in some cases to a decline in the incidence of TB over time [19]. This study, however, did not compare chest radiography screening to other screening strategies in terms of efficacy. Screening procedures vary from one prison site to another. There does not appear to be a large discrepancy in TB incidence regardless of screening technique (symptom survey, PPD, or chest radiograph) [22]. There is no evidence regarding the performance of routine radiography in low-risk patients who did not receive other TB screening before transfer to a group home or nursing facility. Computed tomography CT should be reserved for the rare case in which a chest radiograph is equivocal for active TB and more definitive testing such as sputum culture is impractical. Magnetic resonance imaging Like CT, there is a very limited role for MRI, although it might be considered when cross-sectional imaging is deemed necessary in a patient for whom there is a desire to avoid ionizing radiation. Summary of Recommendations Chest radiography is the first recommended test in patients with suspected tuberculosis. Chest radiography is generally appropriate for patients with new evidence of exposure or at high risk for development of tuberculosis, although it may be of low yield in patients who have no clinical symptoms. Chest CT is appropriate when tuberculosis is suspected and radiography is nonrevealing or nondiagnostic. Although there are references that report on studies with design limitations, 11 well-designed or good-quality studies provide good evidence. Relative Radiation Level Information Potential adverse health effects associated with radiation exposure are an important factor to consider when selecting the appropriate imaging procedure.

Imaging of Possible Tuberculosis. A meta-analysis of homeless populations suggests that using chest radiography as a screening measure is sufficient and can lead in some cases to a decline in the incidence of TB over time [19]. This study, however, did not compare chest radiography screening to other screening strategies in terms of efficacy. Screening procedures vary from one prison site to another. There does not appear to be a large discrepancy in TB incidence regardless of screening technique (symptom survey, PPD, or chest radiograph) [22]. There is no evidence regarding the performance of routine radiography in low-risk patients who did not receive other TB screening before transfer to a group home or nursing facility. Computed tomography CT should be reserved for the rare case in which a chest radiograph is equivocal for active TB and more definitive testing such as sputum culture is impractical. Magnetic resonance imaging Like CT, there is a very limited role for MRI, although it might be considered when cross-sectional imaging is deemed necessary in a patient for whom there is a desire to avoid ionizing radiation. Summary of Recommendations Chest radiography is the first recommended test in patients with suspected tuberculosis. Chest radiography is generally appropriate for patients with new evidence of exposure or at high risk for development of tuberculosis, although it may be of low yield in patients who have no clinical symptoms. Chest CT is appropriate when tuberculosis is suspected and radiography is nonrevealing or nondiagnostic. Although there are references that report on studies with design limitations, 11 well-designed or good-quality studies provide good evidence. Relative Radiation Level Information Potential adverse health effects associated with radiation exposure are an important factor to consider when selecting the appropriate imaging procedure.

3099187

acrac_3094201_0

Suspected Osteomyelitis Septic Arthritis or Soft Tissue Infection Excluding Spine and Diabetic Foot PCAs

Introduction/Background Infections of the musculoskeletal system are a leading cause of pain, disability, and health care encounters. Because of the rise of an aging population, diabetes and obesity, and orthopedic surgeries, the incidence of musculoskeletal infections are also increasing. The overall infection rate following orthopedic hardware placement is estimated to be approximately 5%, and the overall mortality rate associated with necrotizing fasciitis (NF) is >10% [1]. Musculoskeletal infections may have bone and soft tissue involvement and often need imaging using a multimodality approach [2]. The nonspecific signs and symptoms of musculoskeletal infections can make their diagnosis particularly challenging. Predisposing conditions inflammatory arthritis, diabetes, immunosuppression, drug and alcohol abuse, surgery, burns, extremes of body habitus, and poor socioeconomic status can further add to the difficulty of diagnosing musculoskeletal infections both clinically and with imaging [3]. Placement of orthopedic hardware can make imaging diagnosis challenging because of metal artifact, especially on CT and MRI. Imaging plays a critical role in the diagnosis and treatment of musculoskeletal infections. When imaging is appropriately used, proper characterization of bone and soft tissue infections often guides clinical management. Even when infection is clinically apparent, imaging often provides additional information including the extent of infection into deeper tissues, presence of abscesses, joint involvement, and vascular complications. These assessments are central to medical, surgical, and image-guided treatments [4]. OR Discussion of Procedures by Variant Variant 1: Suspected osteomyelitis or septic arthritis or soft tissue infection (excluding spine and diabetic foot). Initial imaging.

Suspected Osteomyelitis Septic Arthritis or Soft Tissue Infection Excluding Spine and Diabetic Foot PCAs. Introduction/Background Infections of the musculoskeletal system are a leading cause of pain, disability, and health care encounters. Because of the rise of an aging population, diabetes and obesity, and orthopedic surgeries, the incidence of musculoskeletal infections are also increasing. The overall infection rate following orthopedic hardware placement is estimated to be approximately 5%, and the overall mortality rate associated with necrotizing fasciitis (NF) is >10% [1]. Musculoskeletal infections may have bone and soft tissue involvement and often need imaging using a multimodality approach [2]. The nonspecific signs and symptoms of musculoskeletal infections can make their diagnosis particularly challenging. Predisposing conditions inflammatory arthritis, diabetes, immunosuppression, drug and alcohol abuse, surgery, burns, extremes of body habitus, and poor socioeconomic status can further add to the difficulty of diagnosing musculoskeletal infections both clinically and with imaging [3]. Placement of orthopedic hardware can make imaging diagnosis challenging because of metal artifact, especially on CT and MRI. Imaging plays a critical role in the diagnosis and treatment of musculoskeletal infections. When imaging is appropriately used, proper characterization of bone and soft tissue infections often guides clinical management. Even when infection is clinically apparent, imaging often provides additional information including the extent of infection into deeper tissues, presence of abscesses, joint involvement, and vascular complications. These assessments are central to medical, surgical, and image-guided treatments [4]. OR Discussion of Procedures by Variant Variant 1: Suspected osteomyelitis or septic arthritis or soft tissue infection (excluding spine and diabetic foot). Initial imaging.

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Suspected Osteomyelitis Septic Arthritis or Soft Tissue Infection Excluding Spine and Diabetic Foot PCAs

For osteomyelitis, the body regions covered are ankle, chest, elbow, femur, foot, forearm, hand, hip, humerus, knee, pelvis, shoulder, tibia/fibula, wrist. For septic arthritis, the body regions covered are ankle, elbow, hip, knee, shoulder, wrist. aUniversity of Virginia, Charlottesville, Virginia. bResearch Author, University of Virginia Health Center, Charlottesville, Virginia. cPanel Chair, Mayo Clinic, Jacksonville, Florida. dPanel Vice-Chair, Wake Forest University School of Medicine, Winston Salem, North Carolina. eThe Johns Hopkins University School of Medicine, Baltimore, Maryland. fMallinckrodt Institute of Radiology Washington University School of Medicine, Saint Louis, Missouri. gAventura Hospital, Aventura, Florida and Nova Southeastern University, Fort Lauderdale, Florida. hMoffitt Cancer Center and University of South Florida Morsani College of Medicine, Tampa, Florida; MSK-RADS (Bone) Committee. iUniversity of Virginia, Charlottesville, Virginia, Primary care physician. jDiagnostic Imaging Associates, Chesterfield, Missouri. kMayo Clinic Florida, Jacksonville, Florida. lSUNY Downstate Health Sciences University, Brooklyn, New York. mMayo Clinic, Jacksonville, Florida; Commission on Nuclear Medicine and Molecular Imaging. nSpecialty Chair, University of Kentucky, Lexington, Kentucky. The American College of Radiology seeks and encourages collaboration with other organizations on the development of the ACR Appropriateness Criteria through representation of such organizations on expert panels. Participation on the expert panel does not necessarily imply endorsement of the final document by individual contributors or their respective organization. Reprint requests to: [email protected] Suspected Osteomyelitis, Septic Arthritis For soft tissue infection, the body regions covered are abdomen, neck, ankle, chest, elbow, thigh, foot, forearm, hand, hip, arm, knee, pelvis, shoulder, leg, wrist.

Suspected Osteomyelitis Septic Arthritis or Soft Tissue Infection Excluding Spine and Diabetic Foot PCAs. For osteomyelitis, the body regions covered are ankle, chest, elbow, femur, foot, forearm, hand, hip, humerus, knee, pelvis, shoulder, tibia/fibula, wrist. For septic arthritis, the body regions covered are ankle, elbow, hip, knee, shoulder, wrist. aUniversity of Virginia, Charlottesville, Virginia. bResearch Author, University of Virginia Health Center, Charlottesville, Virginia. cPanel Chair, Mayo Clinic, Jacksonville, Florida. dPanel Vice-Chair, Wake Forest University School of Medicine, Winston Salem, North Carolina. eThe Johns Hopkins University School of Medicine, Baltimore, Maryland. fMallinckrodt Institute of Radiology Washington University School of Medicine, Saint Louis, Missouri. gAventura Hospital, Aventura, Florida and Nova Southeastern University, Fort Lauderdale, Florida. hMoffitt Cancer Center and University of South Florida Morsani College of Medicine, Tampa, Florida; MSK-RADS (Bone) Committee. iUniversity of Virginia, Charlottesville, Virginia, Primary care physician. jDiagnostic Imaging Associates, Chesterfield, Missouri. kMayo Clinic Florida, Jacksonville, Florida. lSUNY Downstate Health Sciences University, Brooklyn, New York. mMayo Clinic, Jacksonville, Florida; Commission on Nuclear Medicine and Molecular Imaging. nSpecialty Chair, University of Kentucky, Lexington, Kentucky. The American College of Radiology seeks and encourages collaboration with other organizations on the development of the ACR Appropriateness Criteria through representation of such organizations on expert panels. Participation on the expert panel does not necessarily imply endorsement of the final document by individual contributors or their respective organization. Reprint requests to: [email protected] Suspected Osteomyelitis, Septic Arthritis For soft tissue infection, the body regions covered are abdomen, neck, ankle, chest, elbow, thigh, foot, forearm, hand, hip, arm, knee, pelvis, shoulder, leg, wrist.

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Suspected Osteomyelitis Septic Arthritis or Soft Tissue Infection Excluding Spine and Diabetic Foot PCAs

3-Phase Bone Scan Area of Interest There is insufficient evidence to support the use of a 3-phase bone scan area of interest for the initial evaluation of osteomyelitis, septic arthritis, or soft tissue infections. CT Area of Interest There is insufficient evidence to the support the use of CT area of interest for the initial evaluation of osteomyelitis, septic arthritis, or soft tissue infections. MRI Area of Interest There is insufficient evidence to support the use of MRI area of interest for the initial evaluation of osteomyelitis, septic arthritis, or soft tissue infections. Radiography Area of Interest The literature indicates that radiographs should be used for the initial evaluation of musculoskeletal infections, including osteomyelitis, septic arthritis, and soft tissue infection. Erosions and periosteal reaction are common findings in acute osteomyelitis, whereas bone sclerosis is commonly associated with chronic osteomyelitis. In early acute osteomyelitis (<14 days), radiographs may be normal or show only mild soft tissue swelling [5]. Soft tissue swelling, joint effusion, ulcers, effacement of fat planes, gas, and foreign bodies may indicate soft tissue infections or septic arthritis [2]. Many radiographic findings are not specific for infection, and a differential diagnosis may include tumors, trauma, arthritides, metabolic conditions, cardiovascular etiologies, and venous insufficiency or thrombosis. However, obtaining the initial radiograph provides an excellent overview of the anatomic area of interest and can exclude fractures and tumors as the cause of swelling or pain. Radiographs also help with the interpretation of future imaging studies such as CT, MRI, ultrasound (US), and nuclear medicine scans [6]. US Area of Interest There is insufficient evidence to support the use of US area of interest for the initial evaluation of osteomyelitis, septic arthritis, or soft tissue infections.

Suspected Osteomyelitis Septic Arthritis or Soft Tissue Infection Excluding Spine and Diabetic Foot PCAs. 3-Phase Bone Scan Area of Interest There is insufficient evidence to support the use of a 3-phase bone scan area of interest for the initial evaluation of osteomyelitis, septic arthritis, or soft tissue infections. CT Area of Interest There is insufficient evidence to the support the use of CT area of interest for the initial evaluation of osteomyelitis, septic arthritis, or soft tissue infections. MRI Area of Interest There is insufficient evidence to support the use of MRI area of interest for the initial evaluation of osteomyelitis, septic arthritis, or soft tissue infections. Radiography Area of Interest The literature indicates that radiographs should be used for the initial evaluation of musculoskeletal infections, including osteomyelitis, septic arthritis, and soft tissue infection. Erosions and periosteal reaction are common findings in acute osteomyelitis, whereas bone sclerosis is commonly associated with chronic osteomyelitis. In early acute osteomyelitis (<14 days), radiographs may be normal or show only mild soft tissue swelling [5]. Soft tissue swelling, joint effusion, ulcers, effacement of fat planes, gas, and foreign bodies may indicate soft tissue infections or septic arthritis [2]. Many radiographic findings are not specific for infection, and a differential diagnosis may include tumors, trauma, arthritides, metabolic conditions, cardiovascular etiologies, and venous insufficiency or thrombosis. However, obtaining the initial radiograph provides an excellent overview of the anatomic area of interest and can exclude fractures and tumors as the cause of swelling or pain. Radiographs also help with the interpretation of future imaging studies such as CT, MRI, ultrasound (US), and nuclear medicine scans [6]. US Area of Interest There is insufficient evidence to support the use of US area of interest for the initial evaluation of osteomyelitis, septic arthritis, or soft tissue infections.

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Suspected Osteomyelitis Septic Arthritis or Soft Tissue Infection Excluding Spine and Diabetic Foot PCAs

Variant 2: Suspected septic arthritis or soft tissue infection. Initial radiographs normal or with findings suggestive of joint effusion or soft tissue swelling. Next imaging study. For septic arthritis, the body regions covered are ankle, elbow, hip, knee, shoulder, wrist. For soft tissue infection, the body regions covered are abdomen, neck, ankle, chest, elbow, thigh, foot, forearm, hand, hip, arm, knee, pelvis, shoulder, leg, wrist. 3-Phase Bone Scan Area of Interest Radionuclide imaging, which includes 3-phase bone scan, is of limited use for the diagnosis of septic arthritis and soft tissue infection [7]. On 3-phase bone scans, early images may show increased activity with hyperperfusion and hyperemia on flow and blood pool phases. Delayed images may be normal or have increased activity limited to the articular surfaces, in the case of a septic joint [7]. Compared with US, CT, and MRI, bone scan has poor spatial resolution and lacks specificity [4]. However, bone scan can be useful for the evaluation of multifocal infections. Image-Guided Aspiration Area of Interest In many cases, imaging cannot distinguish infected from noninfected joints or fluid collections, and aspiration and culture are needed for diagnosis [8,9]. Culture allows for identification of the infectious organism, which directly affects treatment. Although imaging may delay performing the aspiration, preaspiration imaging with US, CT, or MRI can be essential for planning for a safe aspiration [8]. Image-guided aspiration is ideal because proper, accurate needle placement is confirmed with fluoroscopy, US, CT, and rarely MRI. Also, image guidance significantly reduces vascular complications and injury to nerves. Using image guidance, needle trajectory and placement can be planned to reduce the risk of contaminating normal adjacent tissues [10].

Suspected Osteomyelitis Septic Arthritis or Soft Tissue Infection Excluding Spine and Diabetic Foot PCAs. Variant 2: Suspected septic arthritis or soft tissue infection. Initial radiographs normal or with findings suggestive of joint effusion or soft tissue swelling. Next imaging study. For septic arthritis, the body regions covered are ankle, elbow, hip, knee, shoulder, wrist. For soft tissue infection, the body regions covered are abdomen, neck, ankle, chest, elbow, thigh, foot, forearm, hand, hip, arm, knee, pelvis, shoulder, leg, wrist. 3-Phase Bone Scan Area of Interest Radionuclide imaging, which includes 3-phase bone scan, is of limited use for the diagnosis of septic arthritis and soft tissue infection [7]. On 3-phase bone scans, early images may show increased activity with hyperperfusion and hyperemia on flow and blood pool phases. Delayed images may be normal or have increased activity limited to the articular surfaces, in the case of a septic joint [7]. Compared with US, CT, and MRI, bone scan has poor spatial resolution and lacks specificity [4]. However, bone scan can be useful for the evaluation of multifocal infections. Image-Guided Aspiration Area of Interest In many cases, imaging cannot distinguish infected from noninfected joints or fluid collections, and aspiration and culture are needed for diagnosis [8,9]. Culture allows for identification of the infectious organism, which directly affects treatment. Although imaging may delay performing the aspiration, preaspiration imaging with US, CT, or MRI can be essential for planning for a safe aspiration [8]. Image-guided aspiration is ideal because proper, accurate needle placement is confirmed with fluoroscopy, US, CT, and rarely MRI. Also, image guidance significantly reduces vascular complications and injury to nerves. Using image guidance, needle trajectory and placement can be planned to reduce the risk of contaminating normal adjacent tissues [10].

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Suspected Osteomyelitis Septic Arthritis or Soft Tissue Infection Excluding Spine and Diabetic Foot PCAs

CT Area of Interest CT allows for the evaluation of various soft tissue compartments and may help differentiate cellulitis, myositis, tenosynovitis, abscess, and septic arthritis [11]. CT with intravenous (IV) contrast can assess soft tissue and the extent of infection, which can guide aspiration or surgical debridement. Contrast-enhanced CT can also improve Suspected Osteomyelitis, Septic Arthritis the detection of synovitis, inflammation, fistulas, abscesses, and vascular complications [4]. CT is also the most sensitive modality for detecting soft tissue gas. Although CT is not sensitive at detecting early bone marrow changes, it can show early periosteal reaction and bone erosions, adjacent soft tissue infection, or septic arthritis. MRI Area of Interest MRI allows for the evaluation of musculoskeletal soft tissue infections because of its high sensitivity to fluid and inflammation in bones, joints, muscles, tendons, and other soft tissues [2,6,12]. Because of its excellent spatial and contrast resolution, MRI is excellent at detecting and evaluating the extent of both superficial and deep soft tissue infections [13]. MRI can also exclude soft tissue infection, if edema or fluid signal representing inflammation, joint effusion, or abscess are not present [2,6]. Contrast-enhanced MRI further increases the diagnostic sensitivity for abscesses, fistulas, and vascular complications. Detection of inflammation of joints, bursa, tendons, and muscles is also improved with contrast-enhanced MRI. Compared to CT, soft tissue gas is not as well visualized on MRI. Although MRI often provides imaging for preoperative planning, MRI is not commonly used for image-guided aspiration or drainage. US Area of Interest US is useful for detecting fluid, including joint effusions, abscesses, and infected tendon sheaths.

Suspected Osteomyelitis Septic Arthritis or Soft Tissue Infection Excluding Spine and Diabetic Foot PCAs. CT Area of Interest CT allows for the evaluation of various soft tissue compartments and may help differentiate cellulitis, myositis, tenosynovitis, abscess, and septic arthritis [11]. CT with intravenous (IV) contrast can assess soft tissue and the extent of infection, which can guide aspiration or surgical debridement. Contrast-enhanced CT can also improve Suspected Osteomyelitis, Septic Arthritis the detection of synovitis, inflammation, fistulas, abscesses, and vascular complications [4]. CT is also the most sensitive modality for detecting soft tissue gas. Although CT is not sensitive at detecting early bone marrow changes, it can show early periosteal reaction and bone erosions, adjacent soft tissue infection, or septic arthritis. MRI Area of Interest MRI allows for the evaluation of musculoskeletal soft tissue infections because of its high sensitivity to fluid and inflammation in bones, joints, muscles, tendons, and other soft tissues [2,6,12]. Because of its excellent spatial and contrast resolution, MRI is excellent at detecting and evaluating the extent of both superficial and deep soft tissue infections [13]. MRI can also exclude soft tissue infection, if edema or fluid signal representing inflammation, joint effusion, or abscess are not present [2,6]. Contrast-enhanced MRI further increases the diagnostic sensitivity for abscesses, fistulas, and vascular complications. Detection of inflammation of joints, bursa, tendons, and muscles is also improved with contrast-enhanced MRI. Compared to CT, soft tissue gas is not as well visualized on MRI. Although MRI often provides imaging for preoperative planning, MRI is not commonly used for image-guided aspiration or drainage. US Area of Interest US is useful for detecting fluid, including joint effusions, abscesses, and infected tendon sheaths.

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Suspected Osteomyelitis Septic Arthritis or Soft Tissue Infection Excluding Spine and Diabetic Foot PCAs

US-guided aspirations of soft tissue fluid collections and joint effusions is becoming increasingly common [14]. With the use of color Doppler, vascularity and hyperemia can be assessed without the administration of IV contrast. If needed, US can examine the contralateral side for comparison or extend the area of imaging of suspected infection. Absence of a fluid essentially excludes the diagnosis of septic arthritis, tenosynovitis, and abscess. Gaspari et al [14] reported that US correctly diagnosed an abscess in 29 out of 30 patients and no abscess in 30 of 35 patients with an alternative diagnosis. In comparison, CT correctly diagnosed 23 out of the same 30 patients with abscess and correctly diagnosed 32 of the 35 patients without an abscess. They reported the overall sensitivity and specificity of US for the diagnosis of an abscess as 96.7% and 85.7%, respectively, whereas CT had 76.7% sensitivity and 91.4% for specificity. They concluded that both CT and US are accurate for diagnosing superficial abscesses. US can evaluate the internal characteristics of the abscess cavity, such as necrosis or debris, and associated pathology like foreign bodies, fistulas, and vascular injury. For deeper soft tissue structures and the evaluation of adjacent bone involvement, US is limited compared with MRI and CT. Variant 3: Suspected osteomyelitis. Initial radiographs normal or with findings suggestive of osteomyelitis. Next imaging study. For osteomyelitis, the body regions covered are ankle, chest, elbow, femur, foot, forearm, hand, hip, humerus, knee, pelvis, shoulder, tibia/fibula, wrist. 3-Phase Bone Scan and WBC Scan and Sulfur Colloid Scan Area of Interest These 3 scans are ordered in progression to increase the accuracy of diagnosing osteomyelitis.

Suspected Osteomyelitis Septic Arthritis or Soft Tissue Infection Excluding Spine and Diabetic Foot PCAs. US-guided aspirations of soft tissue fluid collections and joint effusions is becoming increasingly common [14]. With the use of color Doppler, vascularity and hyperemia can be assessed without the administration of IV contrast. If needed, US can examine the contralateral side for comparison or extend the area of imaging of suspected infection. Absence of a fluid essentially excludes the diagnosis of septic arthritis, tenosynovitis, and abscess. Gaspari et al [14] reported that US correctly diagnosed an abscess in 29 out of 30 patients and no abscess in 30 of 35 patients with an alternative diagnosis. In comparison, CT correctly diagnosed 23 out of the same 30 patients with abscess and correctly diagnosed 32 of the 35 patients without an abscess. They reported the overall sensitivity and specificity of US for the diagnosis of an abscess as 96.7% and 85.7%, respectively, whereas CT had 76.7% sensitivity and 91.4% for specificity. They concluded that both CT and US are accurate for diagnosing superficial abscesses. US can evaluate the internal characteristics of the abscess cavity, such as necrosis or debris, and associated pathology like foreign bodies, fistulas, and vascular injury. For deeper soft tissue structures and the evaluation of adjacent bone involvement, US is limited compared with MRI and CT. Variant 3: Suspected osteomyelitis. Initial radiographs normal or with findings suggestive of osteomyelitis. Next imaging study. For osteomyelitis, the body regions covered are ankle, chest, elbow, femur, foot, forearm, hand, hip, humerus, knee, pelvis, shoulder, tibia/fibula, wrist. 3-Phase Bone Scan and WBC Scan and Sulfur Colloid Scan Area of Interest These 3 scans are ordered in progression to increase the accuracy of diagnosing osteomyelitis.

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Suspected Osteomyelitis Septic Arthritis or Soft Tissue Infection Excluding Spine and Diabetic Foot PCAs

If the 3-phase bone scan is positive with increased activity, also obtaining a white blood cell (WBC) scan and Tc-99m sulfur colloid scan may increase specificity for the evaluation of acute osteomyelitis. Addition of sulfur colloid scan may be considered if results remain equivocal following a WBC and 3-phase bone scans. In cases in which radiotracer uptake is increased on WBC scan and 3-phase bone scans, sulfur colloid imaging will show no corresponding radiotracer uptake in cases of osteomyelitis [15,16]. 3-Phase Bone Scan and WBC Scan Area of Interest In patients with low pretest probability of infection who have a positive 3-phase bone scan, the addition of WBC scan may increase specificity for infection, particularly in the setting of recent surgery or fracture at the suspected site of infection [17]. 3-Phase Bone Scan Area of Interest A 3-phase bone scan can be used to rule out osteomyelitis. However, a positive 3-phase bone scan is nonspecific. A meta-analysis performed by Wang et al [17] showed specificity of only 45% for diagnosis of osteomyelitis, whereas sensitivity was 83%. A 3-phase bone scan is most accurate in the diagnosis of osteomyelitis when bone is not affected by other underlying condition such as osteoarthritis, recent fracture, or recent hardware implantation [18]. Addition of single-photon emission CT (SPECT)/CT may be helpful in localization of acute osteomyelitis [19]. Suspected Osteomyelitis, Septic Arthritis CT Area of Interest CT is insensitive in evaluation of acute osteomyelitis. IV contrast administration is helpful for assessing soft tissue involvement. CT may be most useful in characterizing osseous changes from chronic osteomyelitis including detection of sequestrum. Although the use of IV contrast does not improve diagnostic sensitivity for acute osteomyelitis, it may be helpful in the identification of soft tissue infection such as abscess formation [11].

Suspected Osteomyelitis Septic Arthritis or Soft Tissue Infection Excluding Spine and Diabetic Foot PCAs. If the 3-phase bone scan is positive with increased activity, also obtaining a white blood cell (WBC) scan and Tc-99m sulfur colloid scan may increase specificity for the evaluation of acute osteomyelitis. Addition of sulfur colloid scan may be considered if results remain equivocal following a WBC and 3-phase bone scans. In cases in which radiotracer uptake is increased on WBC scan and 3-phase bone scans, sulfur colloid imaging will show no corresponding radiotracer uptake in cases of osteomyelitis [15,16]. 3-Phase Bone Scan and WBC Scan Area of Interest In patients with low pretest probability of infection who have a positive 3-phase bone scan, the addition of WBC scan may increase specificity for infection, particularly in the setting of recent surgery or fracture at the suspected site of infection [17]. 3-Phase Bone Scan Area of Interest A 3-phase bone scan can be used to rule out osteomyelitis. However, a positive 3-phase bone scan is nonspecific. A meta-analysis performed by Wang et al [17] showed specificity of only 45% for diagnosis of osteomyelitis, whereas sensitivity was 83%. A 3-phase bone scan is most accurate in the diagnosis of osteomyelitis when bone is not affected by other underlying condition such as osteoarthritis, recent fracture, or recent hardware implantation [18]. Addition of single-photon emission CT (SPECT)/CT may be helpful in localization of acute osteomyelitis [19]. Suspected Osteomyelitis, Septic Arthritis CT Area of Interest CT is insensitive in evaluation of acute osteomyelitis. IV contrast administration is helpful for assessing soft tissue involvement. CT may be most useful in characterizing osseous changes from chronic osteomyelitis including detection of sequestrum. Although the use of IV contrast does not improve diagnostic sensitivity for acute osteomyelitis, it may be helpful in the identification of soft tissue infection such as abscess formation [11].

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Suspected Osteomyelitis Septic Arthritis or Soft Tissue Infection Excluding Spine and Diabetic Foot PCAs

There is no added benefit in performing multiphase CT imaging before and after IV contrast administration in the evaluation of infection. MRI Area of Interest MRI is highly accurate for detection of acute osteomyelitis. Noncontrast MRI has high sensitivity and specificity in the diagnosis of osteomyelitis. MRI is sensitive at depicting marrow signal changes of acute osteomyelitis. Additionally MRI provides excellent evaluation of the adjacent soft tissues including abscess or fistulas [13,23-26]. The use of IV contrast does not improve diagnosis of peripheral osteomyelitis; however, its use may improve the evaluation of soft tissue infections [27]. US Area of Interest US is of limited benefit in the diagnosis of osteomyelitis. Although findings such as juxtacortical fluid collections and fistulous tracts may be seen, these findings are not specific for osteomyelitis [28]. WBC Scan and Sulfur Colloid Scan Area of Interest A sulfur colloid scan is often performed when WBC scan results are equivocal. If osteomyelitis is present, a sulfur colloid scan will show no radiotracer activity in areas of WBC scan activity. WBC scan combined with marrow imaging has been reported up to 90% accurate in diagnosing osteomyelitis [18]. Disadvantages include low spatial resolution [15,16]. WBC Scan Area of Interest A WBC scan has been reported to have variable sensitivity and specificity when performed alone in the evaluation of osteomyelitis [17]. The addition of SPECT/CT has been suggested to increase the accuracy of WBC scan for the diagnosis of osteomyelitis. When a WBC scan is positive on planar images, SPECT/CT can be performed for more accurate localization of infection [15,21]. Variant 4: Suspected osteomyelitis or soft tissue infection with implanted extra-articular surgical hardware.

Suspected Osteomyelitis Septic Arthritis or Soft Tissue Infection Excluding Spine and Diabetic Foot PCAs. There is no added benefit in performing multiphase CT imaging before and after IV contrast administration in the evaluation of infection. MRI Area of Interest MRI is highly accurate for detection of acute osteomyelitis. Noncontrast MRI has high sensitivity and specificity in the diagnosis of osteomyelitis. MRI is sensitive at depicting marrow signal changes of acute osteomyelitis. Additionally MRI provides excellent evaluation of the adjacent soft tissues including abscess or fistulas [13,23-26]. The use of IV contrast does not improve diagnosis of peripheral osteomyelitis; however, its use may improve the evaluation of soft tissue infections [27]. US Area of Interest US is of limited benefit in the diagnosis of osteomyelitis. Although findings such as juxtacortical fluid collections and fistulous tracts may be seen, these findings are not specific for osteomyelitis [28]. WBC Scan and Sulfur Colloid Scan Area of Interest A sulfur colloid scan is often performed when WBC scan results are equivocal. If osteomyelitis is present, a sulfur colloid scan will show no radiotracer activity in areas of WBC scan activity. WBC scan combined with marrow imaging has been reported up to 90% accurate in diagnosing osteomyelitis [18]. Disadvantages include low spatial resolution [15,16]. WBC Scan Area of Interest A WBC scan has been reported to have variable sensitivity and specificity when performed alone in the evaluation of osteomyelitis [17]. The addition of SPECT/CT has been suggested to increase the accuracy of WBC scan for the diagnosis of osteomyelitis. When a WBC scan is positive on planar images, SPECT/CT can be performed for more accurate localization of infection [15,21]. Variant 4: Suspected osteomyelitis or soft tissue infection with implanted extra-articular surgical hardware.

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Suspected Osteomyelitis Septic Arthritis or Soft Tissue Infection Excluding Spine and Diabetic Foot PCAs

Initial radiographs normal or with findings suggestive of osteomyelitis or soft tissue infection with implanted extra-articular surgical hardware. Next imaging study. For osteomyelitis and soft tissue infection, the body regions covered are ankle, elbow, hip, knee, shoulder, wrist. 3-Phase Bone Scan and WBC Scan and Sulfur Colloid Scan Area of Interest There is insufficient evidence to support the use of 3-phase bone scan, WBC scan, and sulfur colloid scan for the evaluation of infection of extra-articular surgical hardware in the absence of known fluid collection or abscess. 3-Phase Bone Scan and WBC Scan Area of Interest A 3-phase bone scan has low specificity for infection in the setting of trauma or recent surgery. A WBC scan should be considered in patients with a low suspicion of infection who have positive findings on 3-phase bone scan [21]. 3-Phase Bone Scan Area of Interest A meta-analysis by Wang et al [17] found that a 3-phase bone scan had sensitivity of 83% but specificity of <50%. In the setting of prior surgery or trauma, the specificity of 3-phase bone scan is likely even lower because osseous remodeling will result in radiotracer uptake [21]. Although studies have shown that SPECT/CT aids in anatomic localization of infection, findings often remain equivocal [19]. Suspected Osteomyelitis, Septic Arthritis There is insufficient evidence to support the use of image-guided aspiration for evaluation of infection of extra- articular surgical hardware in the absence of known fluid collection or abscess. CT Area of Interest CT is useful in the evaluation of postsurgical complications including hardware fracture, periprosthetic osteolysis, and fracture nonunion [29]. Osseous changes of osteomyelitis can be visualized with CT, although these findings are often nonspecific, particularly if there has been recent trauma or surgery.

Suspected Osteomyelitis Septic Arthritis or Soft Tissue Infection Excluding Spine and Diabetic Foot PCAs. Initial radiographs normal or with findings suggestive of osteomyelitis or soft tissue infection with implanted extra-articular surgical hardware. Next imaging study. For osteomyelitis and soft tissue infection, the body regions covered are ankle, elbow, hip, knee, shoulder, wrist. 3-Phase Bone Scan and WBC Scan and Sulfur Colloid Scan Area of Interest There is insufficient evidence to support the use of 3-phase bone scan, WBC scan, and sulfur colloid scan for the evaluation of infection of extra-articular surgical hardware in the absence of known fluid collection or abscess. 3-Phase Bone Scan and WBC Scan Area of Interest A 3-phase bone scan has low specificity for infection in the setting of trauma or recent surgery. A WBC scan should be considered in patients with a low suspicion of infection who have positive findings on 3-phase bone scan [21]. 3-Phase Bone Scan Area of Interest A meta-analysis by Wang et al [17] found that a 3-phase bone scan had sensitivity of 83% but specificity of <50%. In the setting of prior surgery or trauma, the specificity of 3-phase bone scan is likely even lower because osseous remodeling will result in radiotracer uptake [21]. Although studies have shown that SPECT/CT aids in anatomic localization of infection, findings often remain equivocal [19]. Suspected Osteomyelitis, Septic Arthritis There is insufficient evidence to support the use of image-guided aspiration for evaluation of infection of extra- articular surgical hardware in the absence of known fluid collection or abscess. CT Area of Interest CT is useful in the evaluation of postsurgical complications including hardware fracture, periprosthetic osteolysis, and fracture nonunion [29]. Osseous changes of osteomyelitis can be visualized with CT, although these findings are often nonspecific, particularly if there has been recent trauma or surgery.

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Suspected Osteomyelitis Septic Arthritis or Soft Tissue Infection Excluding Spine and Diabetic Foot PCAs

CT can be helpful in identifying fluid collections adjacent to bone or surgical hardware that can be targeted for further investigation with percutaneous or surgical drainage. CT may also be useful in the detection of necrotic osseous fragments or sequestra that supply a nidus for chronic infection [21]. IV contrast should be considered because this may allow for better definition of fluid collections or fistulous communication to orthopedic implants [22]. FDG-PET/CT Area of Interest A systematic review by Govaert et al [21] found that FDG-PET/CT has specificity for posttraumatic osteomyelitis ranging from 76% to 100% and sensitivity ranging from 83% to 100%. However, in the acute setting, inflammation due to fracture or recent surgery may decrease accuracy. A retrospective review by Hartmann et al [30] demonstrated sensitivity of 100% and specificity ranging from 88% to 93%. This study included patients with orthopedic implants and joint replacements. This small study of 33 patients also suggested that FDG-PET was most specific when evaluating infection in the axial skeleton. Wenter et al [22] retrospectively reviewed PET imaging performed in 215 patients for suspected osteomyelitis or implant associated infection and reported sensitivity of 88% and specificity of 76%. Their results also showed no significant decrease in accuracy in patients with orthopedic implants. MRI Area of Interest MRI is useful for the evaluation of osteomyelitis or soft tissue infection in the setting of extra-articular surgical hardware. MRI allows for characterization of both bone marrow signal and adjacent soft tissues. Recent advances in metal artifact reduction techniques have improved orthopedic hardware imaging, particularly in the appendicular skeleton [31]. In the setting of posttraumatic osteomyelitis, MRI can be used to determine the degree of osseous and soft tissue involvement.

Suspected Osteomyelitis Septic Arthritis or Soft Tissue Infection Excluding Spine and Diabetic Foot PCAs. CT can be helpful in identifying fluid collections adjacent to bone or surgical hardware that can be targeted for further investigation with percutaneous or surgical drainage. CT may also be useful in the detection of necrotic osseous fragments or sequestra that supply a nidus for chronic infection [21]. IV contrast should be considered because this may allow for better definition of fluid collections or fistulous communication to orthopedic implants [22]. FDG-PET/CT Area of Interest A systematic review by Govaert et al [21] found that FDG-PET/CT has specificity for posttraumatic osteomyelitis ranging from 76% to 100% and sensitivity ranging from 83% to 100%. However, in the acute setting, inflammation due to fracture or recent surgery may decrease accuracy. A retrospective review by Hartmann et al [30] demonstrated sensitivity of 100% and specificity ranging from 88% to 93%. This study included patients with orthopedic implants and joint replacements. This small study of 33 patients also suggested that FDG-PET was most specific when evaluating infection in the axial skeleton. Wenter et al [22] retrospectively reviewed PET imaging performed in 215 patients for suspected osteomyelitis or implant associated infection and reported sensitivity of 88% and specificity of 76%. Their results also showed no significant decrease in accuracy in patients with orthopedic implants. MRI Area of Interest MRI is useful for the evaluation of osteomyelitis or soft tissue infection in the setting of extra-articular surgical hardware. MRI allows for characterization of both bone marrow signal and adjacent soft tissues. Recent advances in metal artifact reduction techniques have improved orthopedic hardware imaging, particularly in the appendicular skeleton [31]. In the setting of posttraumatic osteomyelitis, MRI can be used to determine the degree of osseous and soft tissue involvement.

3094201

acrac_3094201_10

Suspected Osteomyelitis Septic Arthritis or Soft Tissue Infection Excluding Spine and Diabetic Foot PCAs

However, caution must be used in the recent postoperative or posttrauma period because bone marrow and soft tissue edema may persist and mimic infection [21]. IV contrast administration is preferred to help evaluate the soft tissues [27,32]. US Area of Interest US may be used in detection of soft tissue abnormalities such as abscess or fistulous tracts. However, assessment of the underlying bone is typically limited with US findings of osteomyelitis either not visualized or nonspecific [28,33]. WBC Scan and Sulfur Colloid Scan Area of Interest Combining a sulfur colloid scan with a WBC scan may reduce false positive results from normal WBC accumulation in bone marrow adjacent to orthopedic hardware. No studies were found that specifically investigated accuracy of combined WBC scan and sulfur colloid scan in diagnosing osteomyelitis associated with extra-articular hardware. Because sulfur colloid is a bone marrow imaging technique, there is no added benefit for assessment of soft tissue infection associated with orthopedic hardware. The addition of SPECT/CT hybrid imaging may increase ability to localize infection in cases with orthopedic hardware. WBC Scan Area of Interest A systematic review by Govaert et al [21] found that a WBC scan for posttraumatic osteomyelitis had sensitivity ranging from 50% to 100% and specificity ranging from 40% to 97%. The addition of SPECT/CT hybrid imaging may increase ability to localize infection in cases with orthopedic hardware. Variant 5: Suspected septic arthritis with arthroplasty or other implanted intra-articular surgical hardware. Initial radiographs normal or with findings suggestive of septic arthritis with arthroplasty or other implanted intra-articular surgical hardware. Next imaging study. For septic arthritis, the body regions covered are ankle, elbow, hip, knee, shoulder, wrist.

Suspected Osteomyelitis Septic Arthritis or Soft Tissue Infection Excluding Spine and Diabetic Foot PCAs. However, caution must be used in the recent postoperative or posttrauma period because bone marrow and soft tissue edema may persist and mimic infection [21]. IV contrast administration is preferred to help evaluate the soft tissues [27,32]. US Area of Interest US may be used in detection of soft tissue abnormalities such as abscess or fistulous tracts. However, assessment of the underlying bone is typically limited with US findings of osteomyelitis either not visualized or nonspecific [28,33]. WBC Scan and Sulfur Colloid Scan Area of Interest Combining a sulfur colloid scan with a WBC scan may reduce false positive results from normal WBC accumulation in bone marrow adjacent to orthopedic hardware. No studies were found that specifically investigated accuracy of combined WBC scan and sulfur colloid scan in diagnosing osteomyelitis associated with extra-articular hardware. Because sulfur colloid is a bone marrow imaging technique, there is no added benefit for assessment of soft tissue infection associated with orthopedic hardware. The addition of SPECT/CT hybrid imaging may increase ability to localize infection in cases with orthopedic hardware. WBC Scan Area of Interest A systematic review by Govaert et al [21] found that a WBC scan for posttraumatic osteomyelitis had sensitivity ranging from 50% to 100% and specificity ranging from 40% to 97%. The addition of SPECT/CT hybrid imaging may increase ability to localize infection in cases with orthopedic hardware. Variant 5: Suspected septic arthritis with arthroplasty or other implanted intra-articular surgical hardware. Initial radiographs normal or with findings suggestive of septic arthritis with arthroplasty or other implanted intra-articular surgical hardware. Next imaging study. For septic arthritis, the body regions covered are ankle, elbow, hip, knee, shoulder, wrist.

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acrac_3094201_11

Suspected Osteomyelitis Septic Arthritis or Soft Tissue Infection Excluding Spine and Diabetic Foot PCAs

3-Phase Bone Scan and WBC Scan and Sulfur Colloid Scan Area of Interest There is insufficient evidence to support the use of 3-phase bone scan, WBC scan, and sulfur colloid scan for evaluation of suspected septic arthritis. Suspected Osteomyelitis, Septic Arthritis 3-Phase Bone Scan and WBC Scan Area of Interest While the literature does not support routine use of 3-phase bone scan and WBC scan for suspected periprosthetic infection, WBC may be performed following a positive bone scan to assess for infection. A 3-phase bone scan can be positive for multiple reasons in the post arthroplasty setting. Trevail et al [34] suggested the addition of WBC scan following a positive arthroplasty is up to 99% specific for infection and 80% sensitive. 3-Phase Bone Scan Area of Interest Bone scintigraphy alone has high sensitivity and low specificity in the evaluation of suspected periprosthetic joint infection [35,36]. A negative 3-phase bone scan suggests low probability of periprosthetic infection [34,37]. Image-Guided Aspiration Area of Interest The use of image-guided joint aspiration is supported to evaluate suspected septic arthritis. Depending on the joint, image guidance may be used to access the joint and confirm intra-articular needle positioning in the event of dry tap. Joint aspiration may be performed under fluoroscopy, US, or, less commonly, CT. The decision of imaging modality should be based on operator expertise and comfort because no modality has been proven superior to others. Laboratory analysis should include cultures, Gram stain, and cell count with differential [31,38,39]. CT Area of Interest CT can be used to evaluate hardware complications including osteolysis adjacent to implanted hardware. The use of metal artifact reduction techniques can improve the detection of joint effusion, soft tissue abscess, and periostitis.

Suspected Osteomyelitis Septic Arthritis or Soft Tissue Infection Excluding Spine and Diabetic Foot PCAs. 3-Phase Bone Scan and WBC Scan and Sulfur Colloid Scan Area of Interest There is insufficient evidence to support the use of 3-phase bone scan, WBC scan, and sulfur colloid scan for evaluation of suspected septic arthritis. Suspected Osteomyelitis, Septic Arthritis 3-Phase Bone Scan and WBC Scan Area of Interest While the literature does not support routine use of 3-phase bone scan and WBC scan for suspected periprosthetic infection, WBC may be performed following a positive bone scan to assess for infection. A 3-phase bone scan can be positive for multiple reasons in the post arthroplasty setting. Trevail et al [34] suggested the addition of WBC scan following a positive arthroplasty is up to 99% specific for infection and 80% sensitive. 3-Phase Bone Scan Area of Interest Bone scintigraphy alone has high sensitivity and low specificity in the evaluation of suspected periprosthetic joint infection [35,36]. A negative 3-phase bone scan suggests low probability of periprosthetic infection [34,37]. Image-Guided Aspiration Area of Interest The use of image-guided joint aspiration is supported to evaluate suspected septic arthritis. Depending on the joint, image guidance may be used to access the joint and confirm intra-articular needle positioning in the event of dry tap. Joint aspiration may be performed under fluoroscopy, US, or, less commonly, CT. The decision of imaging modality should be based on operator expertise and comfort because no modality has been proven superior to others. Laboratory analysis should include cultures, Gram stain, and cell count with differential [31,38,39]. CT Area of Interest CT can be used to evaluate hardware complications including osteolysis adjacent to implanted hardware. The use of metal artifact reduction techniques can improve the detection of joint effusion, soft tissue abscess, and periostitis.

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acrac_3094201_12

Suspected Osteomyelitis Septic Arthritis or Soft Tissue Infection Excluding Spine and Diabetic Foot PCAs

CT is also helpful in identifying necrotic bone fragments or sequestra in the setting of chronic osteomyelitis [21,31]. Although IV contrast is not helpful for assessment of osteomyelitis, the addition of IV contrast may aid in the detection of synovial thickening or soft tissue abscesses [11]. FDG-PET/CT Area of Interest A meta-analysis by Verberne et al [36] showed that there was considerable heterogeneity in the literature regarding the diagnostic criteria for prosthetic joint infection. The authors suggested that radiotracer accumulation around prosthetic head, neck, and distal tip may persist for up to 2 years following implantation, thus limiting evaluation of septic arthritis. Although there seems to be promise for FDG-PET/CT in the evaluation of prosthetic joint infection, the specificity of PET/CT in the diagnosis of septic arthritis remains uncertain because of a lack of clearly defined diagnostic criteria [40]. MRI Area of Interest Although MRI is susceptible to metallic artifact as a result of indwelling hardware, metal reduction sequences have mitigated this as a limitation. MRI is useful at detection of osseous changes of osteomyelitis with high sensitivity and specificity. MRI findings of synovial enhancement, joint effusion, and T1 hypointense bone marrow signal changes have a high correlation with infection [41]. MRI also provides evaluation of adjacent soft tissues including tendons and muscles that may offer an alternative diagnosis to infection in patients with pain following arthroplasty [42]. MRI is accurate for localization of soft tissue fluid collections that may be targeted for aspiration or surgical drainage. One disadvantage of MRI is that bone marrow signal abnormalities may persist for months following injury or surgery. [21]. IV contrast administration should be considered because this can assist in differentiating abscess from phlegmon [32,43].

Suspected Osteomyelitis Septic Arthritis or Soft Tissue Infection Excluding Spine and Diabetic Foot PCAs. CT is also helpful in identifying necrotic bone fragments or sequestra in the setting of chronic osteomyelitis [21,31]. Although IV contrast is not helpful for assessment of osteomyelitis, the addition of IV contrast may aid in the detection of synovial thickening or soft tissue abscesses [11]. FDG-PET/CT Area of Interest A meta-analysis by Verberne et al [36] showed that there was considerable heterogeneity in the literature regarding the diagnostic criteria for prosthetic joint infection. The authors suggested that radiotracer accumulation around prosthetic head, neck, and distal tip may persist for up to 2 years following implantation, thus limiting evaluation of septic arthritis. Although there seems to be promise for FDG-PET/CT in the evaluation of prosthetic joint infection, the specificity of PET/CT in the diagnosis of septic arthritis remains uncertain because of a lack of clearly defined diagnostic criteria [40]. MRI Area of Interest Although MRI is susceptible to metallic artifact as a result of indwelling hardware, metal reduction sequences have mitigated this as a limitation. MRI is useful at detection of osseous changes of osteomyelitis with high sensitivity and specificity. MRI findings of synovial enhancement, joint effusion, and T1 hypointense bone marrow signal changes have a high correlation with infection [41]. MRI also provides evaluation of adjacent soft tissues including tendons and muscles that may offer an alternative diagnosis to infection in patients with pain following arthroplasty [42]. MRI is accurate for localization of soft tissue fluid collections that may be targeted for aspiration or surgical drainage. One disadvantage of MRI is that bone marrow signal abnormalities may persist for months following injury or surgery. [21]. IV contrast administration should be considered because this can assist in differentiating abscess from phlegmon [32,43].

3094201

acrac_3094201_13

Suspected Osteomyelitis Septic Arthritis or Soft Tissue Infection Excluding Spine and Diabetic Foot PCAs

US Area of Interest US may be useful for the detection of synovial thickening or joint effusion. However these are not specific to septic arthritis. US limitations include difficulty imaging deeper structures, deep larger joints (such as the shoulder or hip), an inability to evaluate metal implants, and a lack of sensitivity and specificity to findings such as fistulous tracts, subperiosteal fluid collections, and periosteal thickening [28,33]. WBC Scan and Sulfur Colloid Scan Area of Interest The addition of a sulfur colloid scan is useful in cases in which results are equivocal for septic loosening or osteomyelitis because leukocytes may accumulate in marrow adjacent to orthopedic implants [36,44]. However, the addition of a sulfur colloid bone marrow scan to a WBC scan does not increase the accuracy for detection of septic arthritis. The addition of SPECT/CT is recommended in positive studies to aid in the differentiation of soft tissue infection from osteomyelitis. WBC Scan Area of Interest Systematic reviews by Verberne et al [36] and Van der Bruggen et al [45] both describe significant variability in specificity and sensitivity of WBC scan ability to diagnosis infection of orthopedic implants. This is likely due to Suspected Osteomyelitis, Septic Arthritis variability in scanning technique and criteria used for diagnosis of prosthetic related infection. In a study of 215 patients, Trevail et al [34] reported that a WBC scan had a sensitivity of 80% and a specificity >99%. The addition of SPECT/CT is recommended in positive studies to aid in the differentiation of soft tissue infection from osteomyelitis. Variant 6: Suspected soft tissue infection. History of puncture wound with possible retained foreign body. Radiographs normal. Next imaging study.

Suspected Osteomyelitis Septic Arthritis or Soft Tissue Infection Excluding Spine and Diabetic Foot PCAs. US Area of Interest US may be useful for the detection of synovial thickening or joint effusion. However these are not specific to septic arthritis. US limitations include difficulty imaging deeper structures, deep larger joints (such as the shoulder or hip), an inability to evaluate metal implants, and a lack of sensitivity and specificity to findings such as fistulous tracts, subperiosteal fluid collections, and periosteal thickening [28,33]. WBC Scan and Sulfur Colloid Scan Area of Interest The addition of a sulfur colloid scan is useful in cases in which results are equivocal for septic loosening or osteomyelitis because leukocytes may accumulate in marrow adjacent to orthopedic implants [36,44]. However, the addition of a sulfur colloid bone marrow scan to a WBC scan does not increase the accuracy for detection of septic arthritis. The addition of SPECT/CT is recommended in positive studies to aid in the differentiation of soft tissue infection from osteomyelitis. WBC Scan Area of Interest Systematic reviews by Verberne et al [36] and Van der Bruggen et al [45] both describe significant variability in specificity and sensitivity of WBC scan ability to diagnosis infection of orthopedic implants. This is likely due to Suspected Osteomyelitis, Septic Arthritis variability in scanning technique and criteria used for diagnosis of prosthetic related infection. In a study of 215 patients, Trevail et al [34] reported that a WBC scan had a sensitivity of 80% and a specificity >99%. The addition of SPECT/CT is recommended in positive studies to aid in the differentiation of soft tissue infection from osteomyelitis. Variant 6: Suspected soft tissue infection. History of puncture wound with possible retained foreign body. Radiographs normal. Next imaging study.

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acrac_3094201_14

Suspected Osteomyelitis Septic Arthritis or Soft Tissue Infection Excluding Spine and Diabetic Foot PCAs

For soft tissue infection, the body regions covered are abdomen, neck, ankle, chest, elbow, thigh, foot, forearm, hand, hip, arm, knee, pelvis, shoulder, leg, wrist. In patients with puncture wounds, one of the main goals of imaging is to determine the presence or absence of a retained foreign body. Around the foreign body and puncture wound, soft tissue granulomatous reaction occurs and a superimposed soft tissue infection can develop including cellulitis, abscess, myositis, septic arthritis, or sinus tract. Foreign bodies are either radiodense or radiolucent. Metal, stone, and graphite are radiodense and are detected on radiographs. However, plastic, rubber, and wood are not visible or radiolucent. Glass and ceramic are not always seen on radiographs. CT can evaluate for the complications of foreign body infections such as cellulitis, muscle/fascial edema, abscesses, sinus tracts, and vascular or tendon injuries. Vascular injuries or pseudoaneurysms are best evaluated with the administration of IV contrast. However, soft tissue changes associated with foreign bodies, such as peripheral edema, hyperemia, and inflammation, may require a more sensitive modality such as MRI or US. CT can detect bone changes related to foreign bodies including osseous destruction, sclerosis, periosteal reaction, or intraosseous abscess [46,47]. Although CT can detect foreign bodies embedded in bone, CT is not as sensitive as MRI for detecting bone marrow edema. MRI Area of Interest On MRI, foreign bodies are usually low signal on all sequences and demonstrate morphology that is not anatomic (ie, linear or polygonal shape). MRI is the most sensitive modality for evaluating the soft tissue and osseous changes of infection; however, it is not sensitive or specific for detecting foreign bodies. Especially if the foreign bodies are small, many may be missed.

Suspected Osteomyelitis Septic Arthritis or Soft Tissue Infection Excluding Spine and Diabetic Foot PCAs. For soft tissue infection, the body regions covered are abdomen, neck, ankle, chest, elbow, thigh, foot, forearm, hand, hip, arm, knee, pelvis, shoulder, leg, wrist. In patients with puncture wounds, one of the main goals of imaging is to determine the presence or absence of a retained foreign body. Around the foreign body and puncture wound, soft tissue granulomatous reaction occurs and a superimposed soft tissue infection can develop including cellulitis, abscess, myositis, septic arthritis, or sinus tract. Foreign bodies are either radiodense or radiolucent. Metal, stone, and graphite are radiodense and are detected on radiographs. However, plastic, rubber, and wood are not visible or radiolucent. Glass and ceramic are not always seen on radiographs. CT can evaluate for the complications of foreign body infections such as cellulitis, muscle/fascial edema, abscesses, sinus tracts, and vascular or tendon injuries. Vascular injuries or pseudoaneurysms are best evaluated with the administration of IV contrast. However, soft tissue changes associated with foreign bodies, such as peripheral edema, hyperemia, and inflammation, may require a more sensitive modality such as MRI or US. CT can detect bone changes related to foreign bodies including osseous destruction, sclerosis, periosteal reaction, or intraosseous abscess [46,47]. Although CT can detect foreign bodies embedded in bone, CT is not as sensitive as MRI for detecting bone marrow edema. MRI Area of Interest On MRI, foreign bodies are usually low signal on all sequences and demonstrate morphology that is not anatomic (ie, linear or polygonal shape). MRI is the most sensitive modality for evaluating the soft tissue and osseous changes of infection; however, it is not sensitive or specific for detecting foreign bodies. Especially if the foreign bodies are small, many may be missed.

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acrac_3094201_15

Suspected Osteomyelitis Septic Arthritis or Soft Tissue Infection Excluding Spine and Diabetic Foot PCAs

Because of the granulomatous, inflammatory response to foreign bodies within soft tissues, surrounding fluid signal, edema, peripheral enhancement is a dominant pattern on MRI, which can be used to help localize foreign bodies. MRI with IV contrast can also assess complications of foreign bodies in soft tissues and bone, including cellulitis, fasciitis, abscesses, sinus tracts, osteomyelitis, and vascular or tendon injuries. Compared with US and CT, MRI has a lower sensitivity and inferior spatial resolution for detection of foreign bodies. Radiodense foreign bodies are better visualized on radiography [46]. Metallic foreign bodies and air produce susceptibility artifact, which can limit MRI quality. With metallic objects and MRI, there is a potential for severe soft tissue heating and motion of the foreign body because of the magnetic field. The severity of this risk is dependent on the ferromagnetic properties and location of the metallic foreign body, how long the foreign body has been in place, and the strength of the MRI unit [47]. Therefore, radiographic screening for metallic foreign bodies is recommended before MRI. US Area of Interest If a foreign body is not visualized on radiographs, US can be used for further evaluation especially in the acute, emergency setting [46,47]. US has a reported sensitivity of 95% for the detection of foreign bodies [48]. Tantray et al [48] reported out of 120 patients that went to surgery for foreign body exploration, US visualized foreign bodies in 114 patients. Among the 6 patients with negative US, only 1 patient had a foreign body on surgery. In addition, US can further characterize foreign body morphology, depth, and location in relation to adjacent structures like Suspected Osteomyelitis, Septic Arthritis vessels, bone, joints, tendons, or nerves. Furthermore, US can provide image guidance for removal of the foreign bodies.

Suspected Osteomyelitis Septic Arthritis or Soft Tissue Infection Excluding Spine and Diabetic Foot PCAs. Because of the granulomatous, inflammatory response to foreign bodies within soft tissues, surrounding fluid signal, edema, peripheral enhancement is a dominant pattern on MRI, which can be used to help localize foreign bodies. MRI with IV contrast can also assess complications of foreign bodies in soft tissues and bone, including cellulitis, fasciitis, abscesses, sinus tracts, osteomyelitis, and vascular or tendon injuries. Compared with US and CT, MRI has a lower sensitivity and inferior spatial resolution for detection of foreign bodies. Radiodense foreign bodies are better visualized on radiography [46]. Metallic foreign bodies and air produce susceptibility artifact, which can limit MRI quality. With metallic objects and MRI, there is a potential for severe soft tissue heating and motion of the foreign body because of the magnetic field. The severity of this risk is dependent on the ferromagnetic properties and location of the metallic foreign body, how long the foreign body has been in place, and the strength of the MRI unit [47]. Therefore, radiographic screening for metallic foreign bodies is recommended before MRI. US Area of Interest If a foreign body is not visualized on radiographs, US can be used for further evaluation especially in the acute, emergency setting [46,47]. US has a reported sensitivity of 95% for the detection of foreign bodies [48]. Tantray et al [48] reported out of 120 patients that went to surgery for foreign body exploration, US visualized foreign bodies in 114 patients. Among the 6 patients with negative US, only 1 patient had a foreign body on surgery. In addition, US can further characterize foreign body morphology, depth, and location in relation to adjacent structures like Suspected Osteomyelitis, Septic Arthritis vessels, bone, joints, tendons, or nerves. Furthermore, US can provide image guidance for removal of the foreign bodies.

3094201

acrac_3094201_16

Suspected Osteomyelitis Septic Arthritis or Soft Tissue Infection Excluding Spine and Diabetic Foot PCAs

US can show the complications of foreign body infections such as cellulitis, myositis, abscesses, sinus tracts, and vascular or tendon injuries [47]. All foreign bodies are hyperechoic on US with some degree of posterior acoustic shadowing. A rim of hyperechogenicity may surround the foreign body with increased inflammation and vascularity on color Doppler. This can develop within 24 hours, and it is thought to represent soft tissue granulomatous reaction [47]. Although most superficial foreign bodies are visible on US, deeper locations (>4 cm from the skin) are more difficult to detect on US [46]. It is also difficult to visualize foreign bodies if there is air in the adjacent soft tissues, especially deeper and smaller foreign bodies. US cannot detect foreign bodies within bone. Variant 7: Suspected soft tissue infection. Initial radiographs show soft tissue gas (without puncture wound) or are normal with high clinical suspicion of necrotizing fasciitis. Next imaging study. For soft tissue infection, the body regions covered are abdomen, neck, ankle, chest, elbow, thigh, foot, forearm, hand, hip, arm, knee, pelvis, shoulder, leg, wrist. NF is a rare, rapidly progressive soft tissue infection, which is often difficult to treat and requires surgical intervention with a high mortality rate ranging from 29% to 80% [2,49]. A polymicrobial infection composed of both aerobic and anaerobic organisms is typically seen. The infection causes necrosis by microvascular occlusion along the fascial tissues beginning at the superficial fascia along the subcutaneous soft tissues and then progressing into the deeper fascial layers between muscle planes and compartments [49]. In addition to the clinical findings of NF, laboratory evaluation can be helpful.

Suspected Osteomyelitis Septic Arthritis or Soft Tissue Infection Excluding Spine and Diabetic Foot PCAs. US can show the complications of foreign body infections such as cellulitis, myositis, abscesses, sinus tracts, and vascular or tendon injuries [47]. All foreign bodies are hyperechoic on US with some degree of posterior acoustic shadowing. A rim of hyperechogenicity may surround the foreign body with increased inflammation and vascularity on color Doppler. This can develop within 24 hours, and it is thought to represent soft tissue granulomatous reaction [47]. Although most superficial foreign bodies are visible on US, deeper locations (>4 cm from the skin) are more difficult to detect on US [46]. It is also difficult to visualize foreign bodies if there is air in the adjacent soft tissues, especially deeper and smaller foreign bodies. US cannot detect foreign bodies within bone. Variant 7: Suspected soft tissue infection. Initial radiographs show soft tissue gas (without puncture wound) or are normal with high clinical suspicion of necrotizing fasciitis. Next imaging study. For soft tissue infection, the body regions covered are abdomen, neck, ankle, chest, elbow, thigh, foot, forearm, hand, hip, arm, knee, pelvis, shoulder, leg, wrist. NF is a rare, rapidly progressive soft tissue infection, which is often difficult to treat and requires surgical intervention with a high mortality rate ranging from 29% to 80% [2,49]. A polymicrobial infection composed of both aerobic and anaerobic organisms is typically seen. The infection causes necrosis by microvascular occlusion along the fascial tissues beginning at the superficial fascia along the subcutaneous soft tissues and then progressing into the deeper fascial layers between muscle planes and compartments [49]. In addition to the clinical findings of NF, laboratory evaluation can be helpful.

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acrac_3094201_17

Suspected Osteomyelitis Septic Arthritis or Soft Tissue Infection Excluding Spine and Diabetic Foot PCAs

A scoring system named Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC) is often used, which takes into consideration WBC, hemoglobin, blood chemistry values, and C-reactive protein [50]. Although NF is primarily diagnosed clinically, imaging findings can be critical to support the diagnosis, to aid in surgical planning, and to map disease extent and involvement. However, obtaining imaging studies, such as MRI, should not delay appropriate surgical treatment in patients who are severely ill and unstable [49]. CT Area of Interest The CT findings in NF correlate with the pathophysiology of the infection causing soft tissue inflammation and liquefactive necrosis. Skin thickening, inflammatory subcutaneous fat stranding, and fluid or gas in the superficial or deep fascial planes are the typical CT findings [49,51,52]. In a study evaluating 20 surgically proven cases of NF, Wysoki et al [53] reported that CT demonstrated subcutaneous fat stranding and fascial fluid or thickening in 80%, soft tissue gas in 55%, and abscesses in 35% of cases. Tso et al [52] concluded that although the overall sensitivity of CT in diagnosing NF is 80%, the specificity is low because similar findings may be present in non- NF, cellulitis, pyomyositis, bursitis, and other soft tissue infections. Compared with radiography, US, and MRI, CT is the most sensitive modality for detection of soft tissue gas [51,52,54]. Fernando et al [54] reported in a meta-analysis of 23 studies that the visualization of soft tissue gas on radiographs had a sensitivity of 49% and a specificity of 94% for the diagnosis of NF. Soft tissue gas on CT was associated with a sensitivity of 89% and a specificity of 93% for diagnosing NF. Gas within fascial planes and fluid collections is an important finding and can be a CT hallmark of NF; however, the absence of soft tissue gas does not exclude NF [2,49,51,52].

Suspected Osteomyelitis Septic Arthritis or Soft Tissue Infection Excluding Spine and Diabetic Foot PCAs. A scoring system named Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC) is often used, which takes into consideration WBC, hemoglobin, blood chemistry values, and C-reactive protein [50]. Although NF is primarily diagnosed clinically, imaging findings can be critical to support the diagnosis, to aid in surgical planning, and to map disease extent and involvement. However, obtaining imaging studies, such as MRI, should not delay appropriate surgical treatment in patients who are severely ill and unstable [49]. CT Area of Interest The CT findings in NF correlate with the pathophysiology of the infection causing soft tissue inflammation and liquefactive necrosis. Skin thickening, inflammatory subcutaneous fat stranding, and fluid or gas in the superficial or deep fascial planes are the typical CT findings [49,51,52]. In a study evaluating 20 surgically proven cases of NF, Wysoki et al [53] reported that CT demonstrated subcutaneous fat stranding and fascial fluid or thickening in 80%, soft tissue gas in 55%, and abscesses in 35% of cases. Tso et al [52] concluded that although the overall sensitivity of CT in diagnosing NF is 80%, the specificity is low because similar findings may be present in non- NF, cellulitis, pyomyositis, bursitis, and other soft tissue infections. Compared with radiography, US, and MRI, CT is the most sensitive modality for detection of soft tissue gas [51,52,54]. Fernando et al [54] reported in a meta-analysis of 23 studies that the visualization of soft tissue gas on radiographs had a sensitivity of 49% and a specificity of 94% for the diagnosis of NF. Soft tissue gas on CT was associated with a sensitivity of 89% and a specificity of 93% for diagnosing NF. Gas within fascial planes and fluid collections is an important finding and can be a CT hallmark of NF; however, the absence of soft tissue gas does not exclude NF [2,49,51,52].

3094201

acrac_3094201_18

Suspected Osteomyelitis Septic Arthritis or Soft Tissue Infection Excluding Spine and Diabetic Foot PCAs

Early in the disease process, especially NF infections with more aerobic organisms, and in diabetic patients, soft tissue gas may not be present or detectable by CT [52]. In the Fernando et al meta-analysis of NF studies, most CT examinations were performed without IV contrast or the type of CT examination was not specified [52,54]. The evaluation of the use of contrast-enhanced imaging in the medical literature is limited [2]. Carbonetti et al [51] performed a retrospective study investigating 36 selected patients who had contrast-enhanced CT imaging performed and concern for NF or other severe soft tissue infection, which included confirmed patients with NF (10 surgically proven patients), non-NF (2 patients), cellulitis (10 patients), soft tissue abscess (7 patients), myositis (5 patients), and gas gangrene (2 patients). This study concluded that CT findings of fascial fluid and thickening and lack of enhancement of the fascia after CT with IV contrast administration were both highly associated with NF. The Carbonetti et al study reported that more patients with surgically proven NF had absence of fascial enhancement compared with those with other musculoskeletal infections, suggesting that the absence of fascial enhancement was specific for NF [55]. Contrast-enhanced CT imaging also improves the assessment for abscess, tissue necrosis, and vascular complications [6,52]. However, noncontrast CT is highly accurate for detection of NF [2,49,52,54]. Suspected Osteomyelitis, Septic Arthritis MRI Area of Interest MRI is the modality of choice for detecting superficial or deep fascial fluid or edema [2,49,50,52,56,57]. MRI can recognize small amounts of fluid or edema in the fascia, potentially allowing for earlier diagnosis [54,56].

Suspected Osteomyelitis Septic Arthritis or Soft Tissue Infection Excluding Spine and Diabetic Foot PCAs. Early in the disease process, especially NF infections with more aerobic organisms, and in diabetic patients, soft tissue gas may not be present or detectable by CT [52]. In the Fernando et al meta-analysis of NF studies, most CT examinations were performed without IV contrast or the type of CT examination was not specified [52,54]. The evaluation of the use of contrast-enhanced imaging in the medical literature is limited [2]. Carbonetti et al [51] performed a retrospective study investigating 36 selected patients who had contrast-enhanced CT imaging performed and concern for NF or other severe soft tissue infection, which included confirmed patients with NF (10 surgically proven patients), non-NF (2 patients), cellulitis (10 patients), soft tissue abscess (7 patients), myositis (5 patients), and gas gangrene (2 patients). This study concluded that CT findings of fascial fluid and thickening and lack of enhancement of the fascia after CT with IV contrast administration were both highly associated with NF. The Carbonetti et al study reported that more patients with surgically proven NF had absence of fascial enhancement compared with those with other musculoskeletal infections, suggesting that the absence of fascial enhancement was specific for NF [55]. Contrast-enhanced CT imaging also improves the assessment for abscess, tissue necrosis, and vascular complications [6,52]. However, noncontrast CT is highly accurate for detection of NF [2,49,52,54]. Suspected Osteomyelitis, Septic Arthritis MRI Area of Interest MRI is the modality of choice for detecting superficial or deep fascial fluid or edema [2,49,50,52,56,57]. MRI can recognize small amounts of fluid or edema in the fascia, potentially allowing for earlier diagnosis [54,56].

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acrac_3094201_19

Suspected Osteomyelitis Septic Arthritis or Soft Tissue Infection Excluding Spine and Diabetic Foot PCAs

MRI has the highest reported sensitivity of 93% for the diagnosis of NF because of this detection of fluid signal on T2 fat suppressed or short tau inversion recovery (STIR) sequences [49,52]. Furthermore, the absence of fluid signal along the fascia essentially excludes the diagnosis of NF [2,52,56,57]. However, MRI findings of superficial and deep fascial fluid or edema are not specific for NF and can be seen in other soft tissue infections, such as severe cellulitis and non-NF. If the MRI is negative or with nonspecific findings and there is high clinical suspicion of NF, appropriate surgical treatment should be planned [49]. Also, in stable yet nonimproving patients, obtaining follow- up MRI can be of benefit to assess for progression of necrosis or fascial fluid and edema [49]. Although CT is more sensitive for detecting soft tissue gas, it can be seen as low punctate or curvilinear signal on all MRI sequences (T1-weighted, T2-weighted, STIR) and can be detected with high sensitivity with gradient echo sequences because of blooming artifact and susceptibility artifact. The presence of soft tissue gas is highly associated with NF; however, the absence of soft tissue gas on MRI should not exclude the diagnosis of NF and may be seen in late stages of NF [50,52,56]. Although some degree of fascial thickening, indistinctness of fascial planes, and fluid accumulation can be seen on CT, the MRI high signal intensity appearance of fascial fluid and edema on T2 fat suppression/STIR sequences is far superior for the detection of NF [56]. Yoon et al [50] also compared 2 parameters for diagnosing NF: utilization of the LRINEC score only and when both MRI findings and the LRINEC scores where applied to the diagnostic scenario. When the LRINEC score was used alone, the sensitivity, specificity, positive predictive value, and negative predictive value were 57%, 84%, 77%, and 67%, respectively.

Suspected Osteomyelitis Septic Arthritis or Soft Tissue Infection Excluding Spine and Diabetic Foot PCAs. MRI has the highest reported sensitivity of 93% for the diagnosis of NF because of this detection of fluid signal on T2 fat suppressed or short tau inversion recovery (STIR) sequences [49,52]. Furthermore, the absence of fluid signal along the fascia essentially excludes the diagnosis of NF [2,52,56,57]. However, MRI findings of superficial and deep fascial fluid or edema are not specific for NF and can be seen in other soft tissue infections, such as severe cellulitis and non-NF. If the MRI is negative or with nonspecific findings and there is high clinical suspicion of NF, appropriate surgical treatment should be planned [49]. Also, in stable yet nonimproving patients, obtaining follow- up MRI can be of benefit to assess for progression of necrosis or fascial fluid and edema [49]. Although CT is more sensitive for detecting soft tissue gas, it can be seen as low punctate or curvilinear signal on all MRI sequences (T1-weighted, T2-weighted, STIR) and can be detected with high sensitivity with gradient echo sequences because of blooming artifact and susceptibility artifact. The presence of soft tissue gas is highly associated with NF; however, the absence of soft tissue gas on MRI should not exclude the diagnosis of NF and may be seen in late stages of NF [50,52,56]. Although some degree of fascial thickening, indistinctness of fascial planes, and fluid accumulation can be seen on CT, the MRI high signal intensity appearance of fascial fluid and edema on T2 fat suppression/STIR sequences is far superior for the detection of NF [56]. Yoon et al [50] also compared 2 parameters for diagnosing NF: utilization of the LRINEC score only and when both MRI findings and the LRINEC scores where applied to the diagnostic scenario. When the LRINEC score was used alone, the sensitivity, specificity, positive predictive value, and negative predictive value were 57%, 84%, 77%, and 67%, respectively.

3094201

acrac_3094201_20

Suspected Osteomyelitis Septic Arthritis or Soft Tissue Infection Excluding Spine and Diabetic Foot PCAs

Integrating both MRI findings and LRINEC scoring produced values of 77%, 84%, 82%, and 79%, respectively. They concluded that MRI findings improved the overall sensitivity of diagnosing NF. There are varying reports regarding the amount of fascial enhancement present based on the stage of necrosis [49,52]. Similar to CT, the assessment of fascial enhancement is controversial. Based upon studies in the MRI literature from >20 years ago, NF fascial enhancement patterns following IV contrast administration are variable with nonenhancement, mixed, and enhancement patterns all reported in the medical literature [2,58]. The presence of fascial enhancement is attributed to increased capillary permeability and IV contrast extravasation. In contrast, the absence of fascial enhancement is attributed to necrosis and microvascular occlusion [2,49,52,58]. In the later stages of NF, focal or diffuse nonenhancement of the fascia may be seen because of necrosis, which can be helpful to differentiate from non-NF [50,52,57]. In general, contrast-enhanced MRI aids in the identification of abscess and areas of necrosis, extent of infection, and delineation of vascular involvement, which can be beneficial in NF [2,49,52]. However, noncontrast MRI is still an important examination with the highest reported sensitivities to detect soft tissue findings of fascial edema/fluid signal and can detect the known imaging findings of NF to include deep fascial/intermuscular edema, soft tissue gas, and fluid collections [2,49,50,52,56,57]. US Area of Interest US findings of NF include soft tissue gas, subcutaneous fat edema, and irregular thickening and fluid along superficial and deep fascial planes [52,57,59,60]. A unique benefit to US is the ability to compare the contralateral extremity or other regions of normal tissue.

Suspected Osteomyelitis Septic Arthritis or Soft Tissue Infection Excluding Spine and Diabetic Foot PCAs. Integrating both MRI findings and LRINEC scoring produced values of 77%, 84%, 82%, and 79%, respectively. They concluded that MRI findings improved the overall sensitivity of diagnosing NF. There are varying reports regarding the amount of fascial enhancement present based on the stage of necrosis [49,52]. Similar to CT, the assessment of fascial enhancement is controversial. Based upon studies in the MRI literature from >20 years ago, NF fascial enhancement patterns following IV contrast administration are variable with nonenhancement, mixed, and enhancement patterns all reported in the medical literature [2,58]. The presence of fascial enhancement is attributed to increased capillary permeability and IV contrast extravasation. In contrast, the absence of fascial enhancement is attributed to necrosis and microvascular occlusion [2,49,52,58]. In the later stages of NF, focal or diffuse nonenhancement of the fascia may be seen because of necrosis, which can be helpful to differentiate from non-NF [50,52,57]. In general, contrast-enhanced MRI aids in the identification of abscess and areas of necrosis, extent of infection, and delineation of vascular involvement, which can be beneficial in NF [2,49,52]. However, noncontrast MRI is still an important examination with the highest reported sensitivities to detect soft tissue findings of fascial edema/fluid signal and can detect the known imaging findings of NF to include deep fascial/intermuscular edema, soft tissue gas, and fluid collections [2,49,50,52,56,57]. US Area of Interest US findings of NF include soft tissue gas, subcutaneous fat edema, and irregular thickening and fluid along superficial and deep fascial planes [52,57,59,60]. A unique benefit to US is the ability to compare the contralateral extremity or other regions of normal tissue.

3094201

acrac_3094201_21

Suspected Osteomyelitis Septic Arthritis or Soft Tissue Infection Excluding Spine and Diabetic Foot PCAs

Also, US can evaluate for deep venous thrombosis, provide image guidance for fluid aspiration, use color Doppler, and assess for foreign bodies [52,59]. The US appearance of soft tissue gas is typically an echogenic region or foci along the superficial and/or deep fascia with some degree of incomplete posterior acoustic shadowing. The presence of gas causes the posterior acoustic shadowing, and the changes in echotexture does impede sound penetration which can limit visualization of deeper structures [57]. For NF, this may cause US to have a limited role for the evaluation of the deeper intermuscular fascia especially in larger body habitus patients [52,57]. The subcutaneous fat can be thickened and demonstrate overall increased echogenicity due to fat edema and inflammatory change. Also, the fat lobules can form a cobblestone appearance due to the thickening of subcutaneous fat septa [52,57,59,60]. Although these findings are not specific for NF and Suspected Osteomyelitis, Septic Arthritis can be seen in cellulitis or anasarca, finding irregular thickened fascia and abnormal fluid collections in deeper muscle fascia can help differentiate NF [52,60]. Consistent throughout the US literature is the importance of the detection of fluid accumulation and thickened deep intermuscular fascia for diagnosing NF [52,59-62]. The overall sensitivity of US for the diagnosis of NF varies from 42% to 88%, with a specificity of 70% to 94% [52,59,60]. These variations may be due to the amount of deep fascial thickening and fluid accumulation. There is limited evidence regarding the role of US in the diagnosis of NF [52,57,59,60]. Because CT and MRI are more sensitive modalities for visualizing fluid and fascial thickening, a negative US should not exclude the diagnosis of NF [61].

Suspected Osteomyelitis Septic Arthritis or Soft Tissue Infection Excluding Spine and Diabetic Foot PCAs. Also, US can evaluate for deep venous thrombosis, provide image guidance for fluid aspiration, use color Doppler, and assess for foreign bodies [52,59]. The US appearance of soft tissue gas is typically an echogenic region or foci along the superficial and/or deep fascia with some degree of incomplete posterior acoustic shadowing. The presence of gas causes the posterior acoustic shadowing, and the changes in echotexture does impede sound penetration which can limit visualization of deeper structures [57]. For NF, this may cause US to have a limited role for the evaluation of the deeper intermuscular fascia especially in larger body habitus patients [52,57]. The subcutaneous fat can be thickened and demonstrate overall increased echogenicity due to fat edema and inflammatory change. Also, the fat lobules can form a cobblestone appearance due to the thickening of subcutaneous fat septa [52,57,59,60]. Although these findings are not specific for NF and Suspected Osteomyelitis, Septic Arthritis can be seen in cellulitis or anasarca, finding irregular thickened fascia and abnormal fluid collections in deeper muscle fascia can help differentiate NF [52,60]. Consistent throughout the US literature is the importance of the detection of fluid accumulation and thickened deep intermuscular fascia for diagnosing NF [52,59-62]. The overall sensitivity of US for the diagnosis of NF varies from 42% to 88%, with a specificity of 70% to 94% [52,59,60]. These variations may be due to the amount of deep fascial thickening and fluid accumulation. There is limited evidence regarding the role of US in the diagnosis of NF [52,57,59,60]. Because CT and MRI are more sensitive modalities for visualizing fluid and fascial thickening, a negative US should not exclude the diagnosis of NF [61].

3094201

acrac_69471_0

Dysphagia

Dysphagia affects up to 22% of adults in the primary care setting and is more common in older adults [3,4]. Adults over 65 years of age account for up to two-thirds of all people with dysphagia [3]. Although the aging process is associated with neuromuscular changes, aging itself does not typically cause clinically significant dysphagia. Aging is associated with an increased prevalence of neuromuscular and degenerative disorders that can cause dysphagia; therefore, the presence of dysphagia should prompt evaluation [3,5]. It is also important to recognize that a person may have an asymptomatic swallowing disorder. In one study of 2,000 patients evaluated with videofluoroscopic examinations, 51% of patients were found to aspirate; however, of those who were aspirated, 55% demonstrated silent aspiration with an absent protective cough reflex [6]. Reprint requests to: [email protected] Pharynx Dynamic and Static Imaging Biphasic examination of the pharynx is performed by acquiring static and dynamic images of the pharynx. Double-contrast and single-contrast images of the pharynx and videofluoroscopy of swallowing are obtained. Pharyngeal function, structure, and motility are also assessed. The structural evaluation of the pharynx is superior to that obtained with a modified barium swallow because fluoroscopic spot images are obtained. Therapeutic maneuvers are not typically performed or assessed in this examination. Biphasic Esophagram A biphasic fluoroscopic evaluation of the esophagus includes single- and double-contrast techniques, including full-column, mucosal relief, and double-contrast views of the esophagus [11]. Esophageal function and motility are evaluated at fluoroscopy. Double-contrast technique provides more mucosal detail compared with the single- contrast technique. However, patient cooperation and mobility are required.

Dysphagia. Dysphagia affects up to 22% of adults in the primary care setting and is more common in older adults [3,4]. Adults over 65 years of age account for up to two-thirds of all people with dysphagia [3]. Although the aging process is associated with neuromuscular changes, aging itself does not typically cause clinically significant dysphagia. Aging is associated with an increased prevalence of neuromuscular and degenerative disorders that can cause dysphagia; therefore, the presence of dysphagia should prompt evaluation [3,5]. It is also important to recognize that a person may have an asymptomatic swallowing disorder. In one study of 2,000 patients evaluated with videofluoroscopic examinations, 51% of patients were found to aspirate; however, of those who were aspirated, 55% demonstrated silent aspiration with an absent protective cough reflex [6]. Reprint requests to: [email protected] Pharynx Dynamic and Static Imaging Biphasic examination of the pharynx is performed by acquiring static and dynamic images of the pharynx. Double-contrast and single-contrast images of the pharynx and videofluoroscopy of swallowing are obtained. Pharyngeal function, structure, and motility are also assessed. The structural evaluation of the pharynx is superior to that obtained with a modified barium swallow because fluoroscopic spot images are obtained. Therapeutic maneuvers are not typically performed or assessed in this examination. Biphasic Esophagram A biphasic fluoroscopic evaluation of the esophagus includes single- and double-contrast techniques, including full-column, mucosal relief, and double-contrast views of the esophagus [11]. Esophageal function and motility are evaluated at fluoroscopy. Double-contrast technique provides more mucosal detail compared with the single- contrast technique. However, patient cooperation and mobility are required.

69471

acrac_69471_1

Dysphagia

Single-Contrast Esophagram A single-contrast esophagram or barium swallow includes full-column distension, mucosal relief views, and fluoroscopic observation of esophageal motility. Single-contrast studies are well suited for elderly, debilitated, obese, and postoperative patients as well as patients who are unable to fully cooperate with the biphasic examination. A single-contrast esophagram may be performed with barium or water-soluble contrast. Discussion of Procedures by Variant Variant 1: Oropharyngeal dysphagia with an attributable cause. Initial imaging. An accurate medical and surgical history from the patient or medical record is helpful to determine the appropriate test to optimally assess the patient. Typical functional and neurologic causes of oropharyngeal dysphagia include recent stroke, worsening dementia, myasthenia gravis, or amyotrophic lateral sclerosis. Many patients with oropharyngeal dysphagia can subjectively localize a sensation of blockage or discomfort in the throat. Patients with oropharyngeal dysphagia typically complain of food sticking in the throat or of a globus sensation with a lump in the throat. Other symptoms of oropharyngeal dysfunction include coughing or choking during swallowing (due to laryngeal penetration or aspiration), a nasal-quality voice or nasal regurgitation (due to soft palate insufficiency), food dribbling from the mouth, and difficulty initiating swallow or chewing (due to an abnormal oral phase of swallowing). It is also important to recognize that abnormalities of the mid or distal esophagus or even the gastric cardia may cause referred dysphagia to the upper chest or pharynx, whereas abnormalities of the pharynx rarely cause referred dysphagia to the lower chest [6]. Therefore, the esophagus and cardia should be evaluated in patients with pharyngeal symptoms, particularly if no abnormalities are found in the pharynx to explain these symptoms [12].

Dysphagia. Single-Contrast Esophagram A single-contrast esophagram or barium swallow includes full-column distension, mucosal relief views, and fluoroscopic observation of esophageal motility. Single-contrast studies are well suited for elderly, debilitated, obese, and postoperative patients as well as patients who are unable to fully cooperate with the biphasic examination. A single-contrast esophagram may be performed with barium or water-soluble contrast. Discussion of Procedures by Variant Variant 1: Oropharyngeal dysphagia with an attributable cause. Initial imaging. An accurate medical and surgical history from the patient or medical record is helpful to determine the appropriate test to optimally assess the patient. Typical functional and neurologic causes of oropharyngeal dysphagia include recent stroke, worsening dementia, myasthenia gravis, or amyotrophic lateral sclerosis. Many patients with oropharyngeal dysphagia can subjectively localize a sensation of blockage or discomfort in the throat. Patients with oropharyngeal dysphagia typically complain of food sticking in the throat or of a globus sensation with a lump in the throat. Other symptoms of oropharyngeal dysfunction include coughing or choking during swallowing (due to laryngeal penetration or aspiration), a nasal-quality voice or nasal regurgitation (due to soft palate insufficiency), food dribbling from the mouth, and difficulty initiating swallow or chewing (due to an abnormal oral phase of swallowing). It is also important to recognize that abnormalities of the mid or distal esophagus or even the gastric cardia may cause referred dysphagia to the upper chest or pharynx, whereas abnormalities of the pharynx rarely cause referred dysphagia to the lower chest [6]. Therefore, the esophagus and cardia should be evaluated in patients with pharyngeal symptoms, particularly if no abnormalities are found in the pharynx to explain these symptoms [12].

69471

acrac_69471_2

Dysphagia

Fluoroscopy Pharynx Dynamic and Static Imaging The evaluation of the pharynx with dynamic and static imaging evaluates swallowing function similar to the modified barium swallow. However, this examination typically does not involve a variety of barium consistencies, does not include an evaluation of therapeutic options, and does not evaluate the thoracic esophagus and gastric cardia. Static images aid in evaluation for structural abnormalities of the pharynx. CT Neck and Chest CT is usually not indicated in this clinical scenario because it does not assess oropharyngeal function. Esophageal Transit Nuclear Medicine Scan Scintigraphy is usually not indicated in this clinical scenario because it does not assess the oropharynx. Variant 2: Unexplained oropharyngeal dysphagia. Initial imaging. Patients with unexplained oropharyngeal dysphagia may need a more detailed barium study to determine the cause. Also, because abnormalities of the distal esophagus or gastric cardia can cause referred sensation of dysphagia in the upper chest or pharynx, the esophagus and gastric cardia should be evaluated in patients with pharyngeal symptoms, and a combined radiologic examination of the oral cavity, pharynx, esophagus, and gastric cardia is appropriate for patients with unexplained pharyngeal dysphagia. In patients with unexplained oropharyngeal dysphagia, the combination of videofluoroscopy and static images of the pharynx with an examination of the esophagus has a higher diagnostic value than either videofluoroscopy (such as a modified barium swallow) or static images (such as a biphasic or single-contrast esophagram) alone [17]. If a study is performed using solely static imaging, a biphasic study is preferable to a single-contrast barium swallow because of its superior depiction of mucosal processes. Fluoroscopy Single-Contrast Esophagram Double-contrast technique provides more superior mucosal detail compared with the single-contrast technique.

Dysphagia. Fluoroscopy Pharynx Dynamic and Static Imaging The evaluation of the pharynx with dynamic and static imaging evaluates swallowing function similar to the modified barium swallow. However, this examination typically does not involve a variety of barium consistencies, does not include an evaluation of therapeutic options, and does not evaluate the thoracic esophagus and gastric cardia. Static images aid in evaluation for structural abnormalities of the pharynx. CT Neck and Chest CT is usually not indicated in this clinical scenario because it does not assess oropharyngeal function. Esophageal Transit Nuclear Medicine Scan Scintigraphy is usually not indicated in this clinical scenario because it does not assess the oropharynx. Variant 2: Unexplained oropharyngeal dysphagia. Initial imaging. Patients with unexplained oropharyngeal dysphagia may need a more detailed barium study to determine the cause. Also, because abnormalities of the distal esophagus or gastric cardia can cause referred sensation of dysphagia in the upper chest or pharynx, the esophagus and gastric cardia should be evaluated in patients with pharyngeal symptoms, and a combined radiologic examination of the oral cavity, pharynx, esophagus, and gastric cardia is appropriate for patients with unexplained pharyngeal dysphagia. In patients with unexplained oropharyngeal dysphagia, the combination of videofluoroscopy and static images of the pharynx with an examination of the esophagus has a higher diagnostic value than either videofluoroscopy (such as a modified barium swallow) or static images (such as a biphasic or single-contrast esophagram) alone [17]. If a study is performed using solely static imaging, a biphasic study is preferable to a single-contrast barium swallow because of its superior depiction of mucosal processes. Fluoroscopy Single-Contrast Esophagram Double-contrast technique provides more superior mucosal detail compared with the single-contrast technique.

69471

acrac_69471_3

Dysphagia

However, patient cooperation and mobility are required and single-contrast technique may be better suited for those patients who are unable to fully cooperate with the biphasic examination, such as elderly, debilitated, and obese patients. Fluoroscopy Barium Swallow Modified A modified barium swallow examination may be of benefit in this setting, particularly if structural abnormalities have been excluded by direct endoscopic visualization. In a study by Madhavan et al [19], a videofluoroscopic Dysphagia modified barium swallow identified a cause for dysphagia in 76% of patients. Localization of the videofluoroscopic finding to the site of the patients symptoms was accurate in 75% of cases when the finding was structural versus 18% when the finding was physiologic [19]. CT Neck and Chest CT is usually not indicated in this clinical scenario as initial imaging because it does not assess oropharyngeal and esophageal mucosa and motility. CT may be helpful in the subsequent evaluation of patients if initial studies are not revealing. Esophageal Transit Nuclear Medicine Scan Nuclear scintigraphy could be used to assess for motility abnormalities or gastroesophageal reflux; however, it is not a substitute for examinations that evaluate the function and structure of the pharynx. Variant 3: Retrosternal dysphagia in immunocompetent patients. Initial imaging. Patients with retrosternal dysphagia experience a sensation of blockage or discomfort at any level between the thoracic inlet and the xiphoid process. Because retrosternal dysphagia can be caused by esophageal motility disorders or by structural abnormalities of the esophagus or cardia (ie, esophagitis, rings, strictures, or tumors), a biphasic esophagram is the preferable imaging procedure. Fluoroscopy Biphasic Esophagram The biphasic esophagram permits detection of both structural and functional abnormalities of the esophagus. Structural lesions include esophagitis, strictures, rings, and carcinoma.

Dysphagia. However, patient cooperation and mobility are required and single-contrast technique may be better suited for those patients who are unable to fully cooperate with the biphasic examination, such as elderly, debilitated, and obese patients. Fluoroscopy Barium Swallow Modified A modified barium swallow examination may be of benefit in this setting, particularly if structural abnormalities have been excluded by direct endoscopic visualization. In a study by Madhavan et al [19], a videofluoroscopic Dysphagia modified barium swallow identified a cause for dysphagia in 76% of patients. Localization of the videofluoroscopic finding to the site of the patients symptoms was accurate in 75% of cases when the finding was structural versus 18% when the finding was physiologic [19]. CT Neck and Chest CT is usually not indicated in this clinical scenario as initial imaging because it does not assess oropharyngeal and esophageal mucosa and motility. CT may be helpful in the subsequent evaluation of patients if initial studies are not revealing. Esophageal Transit Nuclear Medicine Scan Nuclear scintigraphy could be used to assess for motility abnormalities or gastroesophageal reflux; however, it is not a substitute for examinations that evaluate the function and structure of the pharynx. Variant 3: Retrosternal dysphagia in immunocompetent patients. Initial imaging. Patients with retrosternal dysphagia experience a sensation of blockage or discomfort at any level between the thoracic inlet and the xiphoid process. Because retrosternal dysphagia can be caused by esophageal motility disorders or by structural abnormalities of the esophagus or cardia (ie, esophagitis, rings, strictures, or tumors), a biphasic esophagram is the preferable imaging procedure. Fluoroscopy Biphasic Esophagram The biphasic esophagram permits detection of both structural and functional abnormalities of the esophagus. Structural lesions include esophagitis, strictures, rings, and carcinoma.

69471

acrac_69471_4

Dysphagia

Functional abnormalities of the esophagus include gastroesophageal reflux and motility disorders. The most important structural lesion is carcinoma of the esophagus or gastroesophageal junction. In one study, biphasic esophagography was found to have 96% sensitivity in diagnosing cancer of the esophagus or esophagogastric junction [20] comparable to the reported sensitivity of endoscopy for diagnosing these lesions. In two other large patient series, endoscopy failed to reveal any cases of esophageal carcinoma that had been missed on the barium studies [21,22]. The findings in these series suggest that endoscopy is not routinely warranted to rule out missed tumors in patients who have normal findings on radiologic examinations. Although double-contrast views best detect mucosal lesions (eg, tumors, esophagitis), prone single-contrast views of patients who continuously drink a low-density barium suspension best detect lower esophageal rings or strictures. Lower esophageal rings are two to three times more likely to be diagnosed on prone single-contrast views than on upright double-contrast views because of inadequate distention of the distal esophagus when the patient is upright [11,23]. In one study, the biphasic esophagram was found to depict about 95% of all lower esophageal rings, whereas endoscopy detected only 76% of these rings [23]. Similarly, biphasic esophagrams have been found to have a sensitivity of about 95% for the detection of peptic strictures, sometimes revealing strictures that are missed with endoscopy [24,25]. The biphasic esophagram is also a useful test in patients with esophageal motility disorders causing dysphagia. Videofluoroscopy of discrete swallows of a low-density barium suspension in the prone right antero-oblique position permits detailed assessment of esophageal motility.

Dysphagia. Functional abnormalities of the esophagus include gastroesophageal reflux and motility disorders. The most important structural lesion is carcinoma of the esophagus or gastroesophageal junction. In one study, biphasic esophagography was found to have 96% sensitivity in diagnosing cancer of the esophagus or esophagogastric junction [20] comparable to the reported sensitivity of endoscopy for diagnosing these lesions. In two other large patient series, endoscopy failed to reveal any cases of esophageal carcinoma that had been missed on the barium studies [21,22]. The findings in these series suggest that endoscopy is not routinely warranted to rule out missed tumors in patients who have normal findings on radiologic examinations. Although double-contrast views best detect mucosal lesions (eg, tumors, esophagitis), prone single-contrast views of patients who continuously drink a low-density barium suspension best detect lower esophageal rings or strictures. Lower esophageal rings are two to three times more likely to be diagnosed on prone single-contrast views than on upright double-contrast views because of inadequate distention of the distal esophagus when the patient is upright [11,23]. In one study, the biphasic esophagram was found to depict about 95% of all lower esophageal rings, whereas endoscopy detected only 76% of these rings [23]. Similarly, biphasic esophagrams have been found to have a sensitivity of about 95% for the detection of peptic strictures, sometimes revealing strictures that are missed with endoscopy [24,25]. The biphasic esophagram is also a useful test in patients with esophageal motility disorders causing dysphagia. Videofluoroscopy of discrete swallows of a low-density barium suspension in the prone right antero-oblique position permits detailed assessment of esophageal motility.

69471

acrac_69471_5

Dysphagia

In various studies, videofluoroscopy has been found to have an overall sensitivity of 80% to 89% and specificity of 79% to 91% for diagnosing esophageal motility disorders (eg, achalasia, diffuse esophageal spasm) compared with esophageal manometry [17,26]. Occasionally, barium studies may even reveal dysmotility not seen at manometry (eg, some patients with the beak-like distal esophageal narrowing of achalasia are found to have complete relaxation of the lower esophageal sphincter on manometry) [27]. Even for those patients with a significant esophageal motility disorder detected on a barium study, manometry may be performed to further elucidate the nature of this motility disorder. Endoscopy performed to evaluate the esophagus for structural abnormalities in patients with dysphagia is a highly accurate test for esophageal cancer when multiple endoscopic biopsy specimens and brushings are obtained. It is also more sensitive than double-contrast esophagography for detecting mild reflux esophagitis or other subtle forms of esophagitis. However, endoscopy is a much more invasive test than the barium study. It is also less sensitive than the barium study for detecting lower esophageal rings or strictures [11,23-25] and does not permit evaluation of esophageal motility disorders. For these reasons, a biphasic esophagram is often recommended as the initial diagnostic test for patients with dysphagia [3,5,28]. Dysphagia Fluoroscopy Single-Contrast Esophagram Although the biphasic esophagram provides superior mucosal detail, allowing for earlier detection of subtle lesions, patient cooperation and mobility are required. For debilitated, immobile patients or patients who are limited in their ability to cooperate, a single-contrast esophagram may be necessary. Fluoroscopy Barium Swallow Modified In patients with retrosternal dysphagia, the entire esophagus and the gastric cardia should be assessed. Therefore, the modified barium swallow may not be appropriate.

Dysphagia. In various studies, videofluoroscopy has been found to have an overall sensitivity of 80% to 89% and specificity of 79% to 91% for diagnosing esophageal motility disorders (eg, achalasia, diffuse esophageal spasm) compared with esophageal manometry [17,26]. Occasionally, barium studies may even reveal dysmotility not seen at manometry (eg, some patients with the beak-like distal esophageal narrowing of achalasia are found to have complete relaxation of the lower esophageal sphincter on manometry) [27]. Even for those patients with a significant esophageal motility disorder detected on a barium study, manometry may be performed to further elucidate the nature of this motility disorder. Endoscopy performed to evaluate the esophagus for structural abnormalities in patients with dysphagia is a highly accurate test for esophageal cancer when multiple endoscopic biopsy specimens and brushings are obtained. It is also more sensitive than double-contrast esophagography for detecting mild reflux esophagitis or other subtle forms of esophagitis. However, endoscopy is a much more invasive test than the barium study. It is also less sensitive than the barium study for detecting lower esophageal rings or strictures [11,23-25] and does not permit evaluation of esophageal motility disorders. For these reasons, a biphasic esophagram is often recommended as the initial diagnostic test for patients with dysphagia [3,5,28]. Dysphagia Fluoroscopy Single-Contrast Esophagram Although the biphasic esophagram provides superior mucosal detail, allowing for earlier detection of subtle lesions, patient cooperation and mobility are required. For debilitated, immobile patients or patients who are limited in their ability to cooperate, a single-contrast esophagram may be necessary. Fluoroscopy Barium Swallow Modified In patients with retrosternal dysphagia, the entire esophagus and the gastric cardia should be assessed. Therefore, the modified barium swallow may not be appropriate.

69471

acrac_69471_6

Dysphagia

Fluoroscopy Pharynx Dynamic and Static Imaging Dynamic and static imaging of the pharynx may not be appropriate as the only examination performed in a patient with retrosternal dysphagia because the entire esophagus and gastric cardia should be assessed. This study does not evaluate the thoracic esophagus or gastric cardia. CT Neck and Chest CT is not usually indicated as an initial imaging modality in this clinical scenario because it does not assess esophageal mucosa and motility. CT may be helpful in the subsequent evaluation of patients if initial studies are not revealing. Esophageal Transit Nuclear Medicine Scan Specific protocols to assess esophageal emptying may be useful in patients with known or suspected achalasia but does not provide anatomic detail [29,30]. Radionuclide esophageal transit scintigraphy is a simple, noninvasive, and quantitative test of esophageal emptying that can be useful in these patients [3,31,32]. Variant 4: Retrosternal dysphagia in immunocompromised patients. Initial imaging. The major consideration in immunocompromised patients with dysphagia or odynophagia (painful swallowing) is infectious esophagitis, most commonly due to Candida albicans or herpes simplex virus. In HIV-positive patients, Candida is most often the cause of esophageal symptoms; cytomegalovirus, herpes simplex, and idiopathic ulcers (also known as HIV ulcers) are the other most common etiologies [33]. HIV-positive patients with esophageal symptoms may be treated empirically with antifungal therapy without first undergoing a diagnostic examination. However, most gastroenterologists prefer that those who have severe symptoms at presentation or persistent symptoms be evaluated by endoscopy. Endoscopy is preferred because of the ability to obtain specimens (eg, histology, cytology, immunostaining, or culture) [3,33].

Dysphagia. Fluoroscopy Pharynx Dynamic and Static Imaging Dynamic and static imaging of the pharynx may not be appropriate as the only examination performed in a patient with retrosternal dysphagia because the entire esophagus and gastric cardia should be assessed. This study does not evaluate the thoracic esophagus or gastric cardia. CT Neck and Chest CT is not usually indicated as an initial imaging modality in this clinical scenario because it does not assess esophageal mucosa and motility. CT may be helpful in the subsequent evaluation of patients if initial studies are not revealing. Esophageal Transit Nuclear Medicine Scan Specific protocols to assess esophageal emptying may be useful in patients with known or suspected achalasia but does not provide anatomic detail [29,30]. Radionuclide esophageal transit scintigraphy is a simple, noninvasive, and quantitative test of esophageal emptying that can be useful in these patients [3,31,32]. Variant 4: Retrosternal dysphagia in immunocompromised patients. Initial imaging. The major consideration in immunocompromised patients with dysphagia or odynophagia (painful swallowing) is infectious esophagitis, most commonly due to Candida albicans or herpes simplex virus. In HIV-positive patients, Candida is most often the cause of esophageal symptoms; cytomegalovirus, herpes simplex, and idiopathic ulcers (also known as HIV ulcers) are the other most common etiologies [33]. HIV-positive patients with esophageal symptoms may be treated empirically with antifungal therapy without first undergoing a diagnostic examination. However, most gastroenterologists prefer that those who have severe symptoms at presentation or persistent symptoms be evaluated by endoscopy. Endoscopy is preferred because of the ability to obtain specimens (eg, histology, cytology, immunostaining, or culture) [3,33].

69471

acrac_69471_7

Dysphagia

The endoscopic or radiographic appearance alone usually does not accurately predict diseases other than Candida esophagitis; diagnosis requires specimen acquisition for laboratory study [33,34]. Fluoroscopy Biphasic Esophagram Esophagrams are preferred by some as an initial diagnostic study and can be useful in guiding management. A biphasic esophagram is more accurate than single-contrast esophagram for detecting ulcers or plaques associated with infectious esophagitis [35-37]. However, a single-contrast esophagram may be performed if the patient is too sick or debilitated to tolerate a double-contrast examination. Patients with radiographically diagnosed Candida or herpes esophagitis may be treated with antifungal or antiviral agents, respectively, without endoscopic evaluation. Endoscopy is warranted for patients with giant esophageal ulcers to differentiate cytomegalovirus and HIV and begin appropriate therapy [34]. Fluoroscopy Single-Contrast Esophagram Although the biphasic esophagram provides superior mucosal detail, allowing for earlier detection of subtle lesions, patient cooperation and mobility are required. For debilitated, immobile patients or patients who are limited in their ability to cooperate, a single-contrast esophagram may be necessary. Fluoroscopy Barium Swallow Modified A modified barium swallow does not evaluate esophageal anatomy and structure. It may not be appropriate because it may fail to reveal the etiology of retrosternal dysphagia. However, it may be useful to evaluate swallowing function in the setting of pharyngeal infection. Fluoroscopy Pharynx Dynamic and Static Imaging Dynamic and static imaging evaluates swallowing and oropharyngeal motility and structure. Performed alone, it may not be appropriate because it may fail to reveal the etiology of retrosternal dysphagia. Dysphagia CT Neck and Chest CT is usually not indicated as an initial imaging modality in this clinical scenario because it does not assess esophageal mucosa and motility.

Dysphagia. The endoscopic or radiographic appearance alone usually does not accurately predict diseases other than Candida esophagitis; diagnosis requires specimen acquisition for laboratory study [33,34]. Fluoroscopy Biphasic Esophagram Esophagrams are preferred by some as an initial diagnostic study and can be useful in guiding management. A biphasic esophagram is more accurate than single-contrast esophagram for detecting ulcers or plaques associated with infectious esophagitis [35-37]. However, a single-contrast esophagram may be performed if the patient is too sick or debilitated to tolerate a double-contrast examination. Patients with radiographically diagnosed Candida or herpes esophagitis may be treated with antifungal or antiviral agents, respectively, without endoscopic evaluation. Endoscopy is warranted for patients with giant esophageal ulcers to differentiate cytomegalovirus and HIV and begin appropriate therapy [34]. Fluoroscopy Single-Contrast Esophagram Although the biphasic esophagram provides superior mucosal detail, allowing for earlier detection of subtle lesions, patient cooperation and mobility are required. For debilitated, immobile patients or patients who are limited in their ability to cooperate, a single-contrast esophagram may be necessary. Fluoroscopy Barium Swallow Modified A modified barium swallow does not evaluate esophageal anatomy and structure. It may not be appropriate because it may fail to reveal the etiology of retrosternal dysphagia. However, it may be useful to evaluate swallowing function in the setting of pharyngeal infection. Fluoroscopy Pharynx Dynamic and Static Imaging Dynamic and static imaging evaluates swallowing and oropharyngeal motility and structure. Performed alone, it may not be appropriate because it may fail to reveal the etiology of retrosternal dysphagia. Dysphagia CT Neck and Chest CT is usually not indicated as an initial imaging modality in this clinical scenario because it does not assess esophageal mucosa and motility.

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Dysphagia

CT may be helpful in the subsequent evaluation of patients if initial studies are not revealing. Esophageal Transit Nuclear Medicine Scan Scintigraphy is usually not indicated in this clinical scenario. Variant 5: Early postoperative dysphagia. Oropharyngeal or retrosternal. Initial imaging. Dysphagia is a common complaint following surgery on the oropharynx, soft tissues of the neck, cervical spine, esophagus, or stomach. Imaging should be tailored to the type and location of surgery (oropharyngeal versus retrosternal) and the time of onset of symptoms following surgery. In the immediate or early postoperative period, fluid collections, anastomotic leaks, perforation, and abscess may be of clinical concern [38]. Fluoroscopy Single-Contrast Esophagram A single-contrast esophagram is the study of choice for patients presenting with dysphagia following surgery to the neck, c-spine, esophagus, or stomach [1,39]. When there is a question of leak or fistula, the study is ideally performed by utilizing water-soluble contrast followed by barium if necessary. Esophagrams are highly specific for the detection of leaks but not sensitive. Roh et al [39] showed that the sensitivity of the esophagram in diagnosing a leak was 36% and specificity was 97%. For this reason, a CT examination may be ordered if there is a high clinical suspicion following a negative esophagram. Lantos et al [40] showed that esophagography had a sensitivity of 79%, specificity of 73%, positive predictive value of 73%, and negative predictive value of 79% for detecting leaks, and esophagography and CT combined had a sensitivity of 100%, specificity of 27%, positive predictive value of 56%, and negative predictive value of 100%. The sensitivity of esophagography increased when high-density barium was administered after water-soluble contrast, whereas the sensitivity of CT was the same with and without oral contrast agent.

Dysphagia. CT may be helpful in the subsequent evaluation of patients if initial studies are not revealing. Esophageal Transit Nuclear Medicine Scan Scintigraphy is usually not indicated in this clinical scenario. Variant 5: Early postoperative dysphagia. Oropharyngeal or retrosternal. Initial imaging. Dysphagia is a common complaint following surgery on the oropharynx, soft tissues of the neck, cervical spine, esophagus, or stomach. Imaging should be tailored to the type and location of surgery (oropharyngeal versus retrosternal) and the time of onset of symptoms following surgery. In the immediate or early postoperative period, fluid collections, anastomotic leaks, perforation, and abscess may be of clinical concern [38]. Fluoroscopy Single-Contrast Esophagram A single-contrast esophagram is the study of choice for patients presenting with dysphagia following surgery to the neck, c-spine, esophagus, or stomach [1,39]. When there is a question of leak or fistula, the study is ideally performed by utilizing water-soluble contrast followed by barium if necessary. Esophagrams are highly specific for the detection of leaks but not sensitive. Roh et al [39] showed that the sensitivity of the esophagram in diagnosing a leak was 36% and specificity was 97%. For this reason, a CT examination may be ordered if there is a high clinical suspicion following a negative esophagram. Lantos et al [40] showed that esophagography had a sensitivity of 79%, specificity of 73%, positive predictive value of 73%, and negative predictive value of 79% for detecting leaks, and esophagography and CT combined had a sensitivity of 100%, specificity of 27%, positive predictive value of 56%, and negative predictive value of 100%. The sensitivity of esophagography increased when high-density barium was administered after water-soluble contrast, whereas the sensitivity of CT was the same with and without oral contrast agent.

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Dysphagia

Esophagrams have a slightly lower sensitivity and substantially higher specificity compared with CT for detecting leaks after esophagectomy [41]. Fluoroscopy Biphasic Esophagram Biphasic esophagram is not usually indicated when a patient has dysphagia in the immediate postoperative period. Single-contrast technique utilizing water-soluble contrast is preferable because evaluation for postoperative leak is the primary concern. Fluoroscopy Barium Swallow Modified When oropharyngeal dysphagia occurs postoperatively and there is a high index of suspicion for swallowing dysfunction, a modified barium swallow is the study of choice, especially if leak has been excluded clinically or with imaging. In the immediate postoperative period, if a leak or perforation is of clinical concern, a single-contrast esophagram with water-soluble contrast may be more appropriate because it is better suited to evaluate postoperative structural abnormalities. However, a modified swallow performed with water-soluble contrast material has been shown to be effective in the diagnosis of leakage [41]. In this study there were no adverse events associated with aspiration of iohexol as water-soluble contrast material [41]. A modified barium swallow examination does not evaluate the entire esophagus. It is not appropriate for postoperative retrosternal dysphagia because it does not evaluate the retrosternal anatomy. Fluoroscopy Pharynx Dynamic and Static Imaging Pharynx dynamic and static imaging is usually not appropriate because it is a double-contrast barium evaluation of the pharynx alone. A single-contrast esophagram with water-soluble contrast possibly followed with barium is more appropriate to evaluate for postoperative leak or fistula in a patient who has had surgery in the neck and is complaining of oropharyngeal dysphagia [42]. Furthermore, this study does not evaluate the thoracic esophagus and gastric cardia.

Dysphagia. Esophagrams have a slightly lower sensitivity and substantially higher specificity compared with CT for detecting leaks after esophagectomy [41]. Fluoroscopy Biphasic Esophagram Biphasic esophagram is not usually indicated when a patient has dysphagia in the immediate postoperative period. Single-contrast technique utilizing water-soluble contrast is preferable because evaluation for postoperative leak is the primary concern. Fluoroscopy Barium Swallow Modified When oropharyngeal dysphagia occurs postoperatively and there is a high index of suspicion for swallowing dysfunction, a modified barium swallow is the study of choice, especially if leak has been excluded clinically or with imaging. In the immediate postoperative period, if a leak or perforation is of clinical concern, a single-contrast esophagram with water-soluble contrast may be more appropriate because it is better suited to evaluate postoperative structural abnormalities. However, a modified swallow performed with water-soluble contrast material has been shown to be effective in the diagnosis of leakage [41]. In this study there were no adverse events associated with aspiration of iohexol as water-soluble contrast material [41]. A modified barium swallow examination does not evaluate the entire esophagus. It is not appropriate for postoperative retrosternal dysphagia because it does not evaluate the retrosternal anatomy. Fluoroscopy Pharynx Dynamic and Static Imaging Pharynx dynamic and static imaging is usually not appropriate because it is a double-contrast barium evaluation of the pharynx alone. A single-contrast esophagram with water-soluble contrast possibly followed with barium is more appropriate to evaluate for postoperative leak or fistula in a patient who has had surgery in the neck and is complaining of oropharyngeal dysphagia [42]. Furthermore, this study does not evaluate the thoracic esophagus and gastric cardia.

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Dysphagia

Alone, pharynx dynamic and static imaging is not appropriate for postoperative retrosternal dysphagia because it does not evaluate the retrosternal anatomy but may be useful combined with esophageal evaluation. CT Neck and Chest For oropharyngeal and retropharyngeal dysphagia, CT of the neck and chest with intravenous (IV) contrast is Dysphagia indicated when there is concern of early postoperative complications, such as leak, fluid collection, abscess, or hematoma [40,43]. CT has a slightly higher sensitivity and substantially lower specificity than esophagography for detecting clinically relevant leaks after esophagectomy [40,43]. The use of CT as the initial imaging test in these patients can lead to earlier diagnosis and treatment of leaks missed on esophagography. In many patients, both CT and esophagrams are performed especially when the clinical concern is high. Lantos et al [40] showed that esophagography had a sensitivity of 79%, specificity of 73%, positive predictive value of 73%, and negative predictive value of 79% for detecting leaks, whereas CT had a sensitivity of 86%, specificity of 33%, positive predictive value of 55%, and negative predictive value of 71%; esophagography and CT combined had a sensitivity of 100%, specificity of 27%, positive predictive value of 56%, and negative predictive value of 100%. CT may be useful to assess the position of surgical hardware or complication related to surgical hardware with respect to the oropharynx and airway. Oral contrast administered immediately before the examination may be a helpful adjunct to facilitate interpretation of esophageal integrity and anatomy, though one study showed the use of oral contrast did not change the sensitivity of CT for detection of leaks [40]. CT scan with IV contrast better defines the anatomic structures of the neck and chest compared to CT without IV contrast because normal soft-tissue and blood vessel enhancement are better delineated from postoperative fluid collections, such as hematomas and abscesses.

Dysphagia. Alone, pharynx dynamic and static imaging is not appropriate for postoperative retrosternal dysphagia because it does not evaluate the retrosternal anatomy but may be useful combined with esophageal evaluation. CT Neck and Chest For oropharyngeal and retropharyngeal dysphagia, CT of the neck and chest with intravenous (IV) contrast is Dysphagia indicated when there is concern of early postoperative complications, such as leak, fluid collection, abscess, or hematoma [40,43]. CT has a slightly higher sensitivity and substantially lower specificity than esophagography for detecting clinically relevant leaks after esophagectomy [40,43]. The use of CT as the initial imaging test in these patients can lead to earlier diagnosis and treatment of leaks missed on esophagography. In many patients, both CT and esophagrams are performed especially when the clinical concern is high. Lantos et al [40] showed that esophagography had a sensitivity of 79%, specificity of 73%, positive predictive value of 73%, and negative predictive value of 79% for detecting leaks, whereas CT had a sensitivity of 86%, specificity of 33%, positive predictive value of 55%, and negative predictive value of 71%; esophagography and CT combined had a sensitivity of 100%, specificity of 27%, positive predictive value of 56%, and negative predictive value of 100%. CT may be useful to assess the position of surgical hardware or complication related to surgical hardware with respect to the oropharynx and airway. Oral contrast administered immediately before the examination may be a helpful adjunct to facilitate interpretation of esophageal integrity and anatomy, though one study showed the use of oral contrast did not change the sensitivity of CT for detection of leaks [40]. CT scan with IV contrast better defines the anatomic structures of the neck and chest compared to CT without IV contrast because normal soft-tissue and blood vessel enhancement are better delineated from postoperative fluid collections, such as hematomas and abscesses.

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acrac_69471_11

Dysphagia

Obtaining a CT scan with and without IV contrast offers little additional benefit compared to a CT with IV contrast alone. Esophageal Transit Nuclear Medicine Scan Scintigraphy is usually not indicated in this clinical scenario. Variant 6: Delayed (greater than 1 month) postoperative development of dysphagia. Oropharyngeal or retrosternal. Initial imaging. Dysphagia occurring weeks or months following surgery may be due to dysmotility, gastroesophageal reflux, or structural abnormalities, such as anastomotic strictures, diverticula, or recurrent disease [38]. The incidence of dysphagia after laryngectomy is reported to occur in up to 72% of patients [44], and aspiration occurs in 65% of patients [45]. In addition to patients who have undergone operations to the oropharynx, larynx, and esophagus, operative procedures on the cervical spine may also cause dysphagia and significant disability. In the latter group of patients, dysphagia may be caused by structural abnormalities (displaced surgical hardware or bone graft) or functional abnormalities resulting in aspiration or penetration [1]. Patients following esophageal and gastric surgery can also experience dysphagia related to many potential complications. Fluoroscopy Pharynx Dynamic and Static Imaging Pharynx dynamic and static imaging is usually not appropriate because it is a double-contrast barium evaluation of the pharynx alone. A single-contrast esophagram with water-soluble contrast possibly followed with barium is more appropriate to evaluate for postoperative leak or fistula in a patient who has had surgery in the neck and is complaining of oropharyngeal dysphagia [42]. Furthermore, this study does not evaluate the thoracic esophagus Dysphagia and gastric cardia. Alone, pharynx dynamic and static imaging is not appropriate for postoperative retrosternal dysphagia because it does not evaluate the retrosternal anatomy but may be useful combined with esophageal evaluation.

Dysphagia. Obtaining a CT scan with and without IV contrast offers little additional benefit compared to a CT with IV contrast alone. Esophageal Transit Nuclear Medicine Scan Scintigraphy is usually not indicated in this clinical scenario. Variant 6: Delayed (greater than 1 month) postoperative development of dysphagia. Oropharyngeal or retrosternal. Initial imaging. Dysphagia occurring weeks or months following surgery may be due to dysmotility, gastroesophageal reflux, or structural abnormalities, such as anastomotic strictures, diverticula, or recurrent disease [38]. The incidence of dysphagia after laryngectomy is reported to occur in up to 72% of patients [44], and aspiration occurs in 65% of patients [45]. In addition to patients who have undergone operations to the oropharynx, larynx, and esophagus, operative procedures on the cervical spine may also cause dysphagia and significant disability. In the latter group of patients, dysphagia may be caused by structural abnormalities (displaced surgical hardware or bone graft) or functional abnormalities resulting in aspiration or penetration [1]. Patients following esophageal and gastric surgery can also experience dysphagia related to many potential complications. Fluoroscopy Pharynx Dynamic and Static Imaging Pharynx dynamic and static imaging is usually not appropriate because it is a double-contrast barium evaluation of the pharynx alone. A single-contrast esophagram with water-soluble contrast possibly followed with barium is more appropriate to evaluate for postoperative leak or fistula in a patient who has had surgery in the neck and is complaining of oropharyngeal dysphagia [42]. Furthermore, this study does not evaluate the thoracic esophagus Dysphagia and gastric cardia. Alone, pharynx dynamic and static imaging is not appropriate for postoperative retrosternal dysphagia because it does not evaluate the retrosternal anatomy but may be useful combined with esophageal evaluation.

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acrac_3102223_0

Lower Extremity Arterial Revascularization Post Therapy Imaging

Over the past several decades, a paradigm shift away from surgical treatment and toward endovascular therapy for PAD has occurred, with many now advocating surgical treatments only after one or more failed endovascular revascularization attempts. The BASIL trial demonstrated that patients with critical limb ischemia (CLI) presenting with rest pain, ulceration, and gangrene of the leg due to infrainguinal disease had similar amputation- free survival and quality-of-life outcomes whether they were randomized to a surgery-first or angioplasty-first treatment strategy. Furthermore, first-year costs associated with bypass surgery were about one-third higher than those associated with angioplasty [5]. The long-term outcomes following surgical and endovascular therapy in the setting of CLI are the subject of the ongoing BEST-CLI trial, which has an estimated primary endpoint completion date in December 2018. Whether endovascular or surgical revascularization is used, restenosis is a pervasive issue. As target lesion restenosis and adjacent segment disease typically precede frank occlusion and CLI, surveillance has been advocated for many years in the setting of bypass, and there is increasing evidence to support its use following angioplasty and stenting. Additionally, there has been a steady increase in the investigative tools available to the vascular specialist to diagnose and stratify lesions in the lower extremity arteries. Because of the plethora of testing options available, it can be difficult for physicians to determine the most appropriate test to obtain in the setting of recurrent symptoms after therapy. Overview of Imaging Modalities Noninvasive Hemodynamic Testing Noninvasive testing (NIVT), both before and after intervention, has been used for decades as a first-line investigatory tool in the diagnosis and categorization of PAD.

Lower Extremity Arterial Revascularization Post Therapy Imaging. Over the past several decades, a paradigm shift away from surgical treatment and toward endovascular therapy for PAD has occurred, with many now advocating surgical treatments only after one or more failed endovascular revascularization attempts. The BASIL trial demonstrated that patients with critical limb ischemia (CLI) presenting with rest pain, ulceration, and gangrene of the leg due to infrainguinal disease had similar amputation- free survival and quality-of-life outcomes whether they were randomized to a surgery-first or angioplasty-first treatment strategy. Furthermore, first-year costs associated with bypass surgery were about one-third higher than those associated with angioplasty [5]. The long-term outcomes following surgical and endovascular therapy in the setting of CLI are the subject of the ongoing BEST-CLI trial, which has an estimated primary endpoint completion date in December 2018. Whether endovascular or surgical revascularization is used, restenosis is a pervasive issue. As target lesion restenosis and adjacent segment disease typically precede frank occlusion and CLI, surveillance has been advocated for many years in the setting of bypass, and there is increasing evidence to support its use following angioplasty and stenting. Additionally, there has been a steady increase in the investigative tools available to the vascular specialist to diagnose and stratify lesions in the lower extremity arteries. Because of the plethora of testing options available, it can be difficult for physicians to determine the most appropriate test to obtain in the setting of recurrent symptoms after therapy. Overview of Imaging Modalities Noninvasive Hemodynamic Testing Noninvasive testing (NIVT), both before and after intervention, has been used for decades as a first-line investigatory tool in the diagnosis and categorization of PAD.

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Lower Extremity Arterial Revascularization Post Therapy Imaging

It is widely available and provides a large amount of information at low cost without the use of ionizing radiation [6]. NIVT can consist of one or more of the following components: the ABI, segmental pressure measurements (SPMs), pulse-volume recordings (PVRs), photoplethysmography (PPG), and transcutaneous oxygen pressure measurement (TcPO2). aResearch Author, University of Michigan Health System, Ann Arbor, Michigan. bPrincipal Author and Panel Vice-chair, University of Michigan Health System, Ann Arbor, Michigan. cPanel Chair, UT Southwestern Medical Center, Dallas, Texas. dScripps Green Hospital, La Jolla, California; Society for Vascular Surgery. eNorthwestern Medicine, Chicago, Illinois. fUniversity of Wisconsin, Madison, Wisconsin. gMassachusetts General Hospital, Boston, Massachusetts. hCleveland Clinic Heart and Vascular Institute, Cleveland, Ohio; American College of Cardiology. iMayo Clinic, Rochester, Minnesota. jUniversity of Michigan Health System, Ann Arbor, Michigan. kUniversity of California San Diego, San Diego, California. lUniversity of Virginia Health System, Charlottesville, Virginia. mLoyola University Medical Center, Maywood, Illinois. nColumbia University Medical Center, New York, New York. oUT Southwestern Medical Center, Dallas, Texas. pSpecialty Chair, Ottawa Hospital Research Institute and the Department of Radiology, The University of Ottawa, Ottawa, Ontario, Canada. The American College of Radiology seeks and encourages collaboration with other organizations on the development of the ACR Appropriateness Criteria through society representation on expert panels. Participation by representatives from collaborating societies on the expert panel does not necessarily imply individual or society endorsement of the final document. Reprint requests to: [email protected] PVRs provide a qualitative (rather than quantitative) measurement of limb perfusion.

Lower Extremity Arterial Revascularization Post Therapy Imaging. It is widely available and provides a large amount of information at low cost without the use of ionizing radiation [6]. NIVT can consist of one or more of the following components: the ABI, segmental pressure measurements (SPMs), pulse-volume recordings (PVRs), photoplethysmography (PPG), and transcutaneous oxygen pressure measurement (TcPO2). aResearch Author, University of Michigan Health System, Ann Arbor, Michigan. bPrincipal Author and Panel Vice-chair, University of Michigan Health System, Ann Arbor, Michigan. cPanel Chair, UT Southwestern Medical Center, Dallas, Texas. dScripps Green Hospital, La Jolla, California; Society for Vascular Surgery. eNorthwestern Medicine, Chicago, Illinois. fUniversity of Wisconsin, Madison, Wisconsin. gMassachusetts General Hospital, Boston, Massachusetts. hCleveland Clinic Heart and Vascular Institute, Cleveland, Ohio; American College of Cardiology. iMayo Clinic, Rochester, Minnesota. jUniversity of Michigan Health System, Ann Arbor, Michigan. kUniversity of California San Diego, San Diego, California. lUniversity of Virginia Health System, Charlottesville, Virginia. mLoyola University Medical Center, Maywood, Illinois. nColumbia University Medical Center, New York, New York. oUT Southwestern Medical Center, Dallas, Texas. pSpecialty Chair, Ottawa Hospital Research Institute and the Department of Radiology, The University of Ottawa, Ottawa, Ontario, Canada. The American College of Radiology seeks and encourages collaboration with other organizations on the development of the ACR Appropriateness Criteria through society representation on expert panels. Participation by representatives from collaborating societies on the expert panel does not necessarily imply individual or society endorsement of the final document. Reprint requests to: [email protected] PVRs provide a qualitative (rather than quantitative) measurement of limb perfusion.

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Lower Extremity Arterial Revascularization Post Therapy Imaging

PVRs are created by inflating pneumoplethysmography cuffs to a specified pressure at predetermined levels on each limb. Each cuff measures the miniscule change in the volume of the limb under the cuff with each pulse, creating a tracing of volume versus time. The resultant waveforms can be compared to determine segmental disease, providing insight into the quality of arterial blood flow at each station simultaneously. PVRs are also useful in patients with noncompressible vessels, as this modality relies on limb volume change rather than the pressure required impeding flow through the vessel being interrogated. PPG involves the detection of a transmitted infrared signal through each of the digits. The degree of transmitted signal varies depending on blood volume within the digit, blood vessel wall movement, and the orientation of red blood cells [12]. PPG is useful for detection of disease below the knee as well as disease isolated to the forefoot and digits. As such, it has been demonstrated to be a complementary test to ABI, which has limited use in these segments. TcPO2 measurement allows the determination of the oxygen tension within tissue. An improvement in the TcPO2 value postintervention compared with preintervention has been validated as an excellent marker of tissue reperfusion [13]. TcPO2 values >40 mmHg in the area surrounding the ulcer or amputation site are considered predictive of successful healing. This test is not limited by noncompressible vessels, and, in patients without pedal Doppler signals, it is one of the few NIVTs that is helpful [14]. The test is limited by its availability in the office setting, patient resistance to avoiding smoking and caffeine prior to the test, as well as the time and cost constraints associated with providing the temperature-controlled environment required to standardize the test.

Lower Extremity Arterial Revascularization Post Therapy Imaging. PVRs are created by inflating pneumoplethysmography cuffs to a specified pressure at predetermined levels on each limb. Each cuff measures the miniscule change in the volume of the limb under the cuff with each pulse, creating a tracing of volume versus time. The resultant waveforms can be compared to determine segmental disease, providing insight into the quality of arterial blood flow at each station simultaneously. PVRs are also useful in patients with noncompressible vessels, as this modality relies on limb volume change rather than the pressure required impeding flow through the vessel being interrogated. PPG involves the detection of a transmitted infrared signal through each of the digits. The degree of transmitted signal varies depending on blood volume within the digit, blood vessel wall movement, and the orientation of red blood cells [12]. PPG is useful for detection of disease below the knee as well as disease isolated to the forefoot and digits. As such, it has been demonstrated to be a complementary test to ABI, which has limited use in these segments. TcPO2 measurement allows the determination of the oxygen tension within tissue. An improvement in the TcPO2 value postintervention compared with preintervention has been validated as an excellent marker of tissue reperfusion [13]. TcPO2 values >40 mmHg in the area surrounding the ulcer or amputation site are considered predictive of successful healing. This test is not limited by noncompressible vessels, and, in patients without pedal Doppler signals, it is one of the few NIVTs that is helpful [14]. The test is limited by its availability in the office setting, patient resistance to avoiding smoking and caffeine prior to the test, as well as the time and cost constraints associated with providing the temperature-controlled environment required to standardize the test.

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Lower Extremity Arterial Revascularization Post Therapy Imaging

US Peripheral duplex ultrasound (DUS) imaging, which consists of grayscale 2-D imaging, color Doppler, and spectral waveform analysis, has been a mainstay of vascular imaging for decades. This technology is widely available, portable, does not require contrast agents, and can be used in the angiography suite or operating room. DUS has been validated as a screening tool [15], a first-line study for clinically suspected PAD [16], and as a tool to plan the approach for both endovascular and surgical intervention [17]. In most situations, it is complimentary to NIVT, such as the ABI [18]. US has a high sensitivity for the detection of patent tibial arteries but is less accurate in detecting complete occlusions, particularly in the peroneal artery [19]. DUS has also been used to quantify the firmness of occlusions to determine the degree of chronicity to some success [20]. Lower Extremity Arterial Revascularization correlate well with symptom recurrence [26]. When planning interventions, the anticipated intervention based on US alone was unchanged after angiogram in femoropopliteal and iliac lesions in >80% of patients, but only 59% in lesions below the knee [27]. In critical limbs, close surveillance shows significant improvement in limb salvage rates over clinical follow-up alone [28]. Unfortunately, of all the noninvasive imaging techniques, US is also the most operator dependent and time consuming [29]. The DIPAD trial, which evaluates the cost-benefit ratio of DUS compared with computed tomography angiography (CTA) and contrast-enhanced magnetic resonance angiography (CE-MRA), showed that although the initial cost of US is lower, this does not take into account the time-related expense and operator experience required to produce satisfactory imaging. Additionally, practitioner confidence in the results is often lower than with the more advanced techniques, leading to a greater number of follow-up studies prior to intervention [30].

Lower Extremity Arterial Revascularization Post Therapy Imaging. US Peripheral duplex ultrasound (DUS) imaging, which consists of grayscale 2-D imaging, color Doppler, and spectral waveform analysis, has been a mainstay of vascular imaging for decades. This technology is widely available, portable, does not require contrast agents, and can be used in the angiography suite or operating room. DUS has been validated as a screening tool [15], a first-line study for clinically suspected PAD [16], and as a tool to plan the approach for both endovascular and surgical intervention [17]. In most situations, it is complimentary to NIVT, such as the ABI [18]. US has a high sensitivity for the detection of patent tibial arteries but is less accurate in detecting complete occlusions, particularly in the peroneal artery [19]. DUS has also been used to quantify the firmness of occlusions to determine the degree of chronicity to some success [20]. Lower Extremity Arterial Revascularization correlate well with symptom recurrence [26]. When planning interventions, the anticipated intervention based on US alone was unchanged after angiogram in femoropopliteal and iliac lesions in >80% of patients, but only 59% in lesions below the knee [27]. In critical limbs, close surveillance shows significant improvement in limb salvage rates over clinical follow-up alone [28]. Unfortunately, of all the noninvasive imaging techniques, US is also the most operator dependent and time consuming [29]. The DIPAD trial, which evaluates the cost-benefit ratio of DUS compared with computed tomography angiography (CTA) and contrast-enhanced magnetic resonance angiography (CE-MRA), showed that although the initial cost of US is lower, this does not take into account the time-related expense and operator experience required to produce satisfactory imaging. Additionally, practitioner confidence in the results is often lower than with the more advanced techniques, leading to a greater number of follow-up studies prior to intervention [30].

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Lower Extremity Arterial Revascularization Post Therapy Imaging

CTA Modern CTA has been demonstrated to be comparable to the gold standard (catheter-based angiography) for the detection of hemodynamically significant stenoses (>50%) with sensitivity, specificity, and accuracy of 99%, 98%, and 98%, respectively [31]. Refinements in CT protocols have also compared favorably to MRA with no statistically significant difference between the two modalities in the evaluation of claudication or CLI [32]. Arterial opacification is significantly improved by using high-density compact contrast boluses, which is rapidly becoming the standard of care with equivalent iodine dose to previous standard bolus technique [33]. Potential drawbacks of CTA include the exposure to ionizing radiation and the use of iodinated contrast, which presents the potential for allergic reaction or contrast-induced nephropathy, particularly in those patients who already possess some degree of renal impairment. Metallic streak artifact is often problematic in patients with postsurgical changes or implanted hardware. Additionally, in extremely obese patients, the signal-to-noise ratio becomes somewhat prohibitive. Evaluation of densely calcified vessels can be difficult with CTA because of the similar density between plaque and contrast and the blooming artifact created by the former, leading to overestimation of the degree of stenosis in many cases, as well as the inability to determine patency in stented vessels. Because of the density of calcified plaque in relation to the relatively small lumen of the tibial vessels, CTA has traditionally suffered in the infrageniculate distribution [34]. Multiple studies have now validated dual-energy CTA as a practical and effective method for subtraction of calcified plaque and soft tissues, allowing for simultaneous creation of conventional CTA data sets and angiogram-like composite images of the vasculature alone.

Lower Extremity Arterial Revascularization Post Therapy Imaging. CTA Modern CTA has been demonstrated to be comparable to the gold standard (catheter-based angiography) for the detection of hemodynamically significant stenoses (>50%) with sensitivity, specificity, and accuracy of 99%, 98%, and 98%, respectively [31]. Refinements in CT protocols have also compared favorably to MRA with no statistically significant difference between the two modalities in the evaluation of claudication or CLI [32]. Arterial opacification is significantly improved by using high-density compact contrast boluses, which is rapidly becoming the standard of care with equivalent iodine dose to previous standard bolus technique [33]. Potential drawbacks of CTA include the exposure to ionizing radiation and the use of iodinated contrast, which presents the potential for allergic reaction or contrast-induced nephropathy, particularly in those patients who already possess some degree of renal impairment. Metallic streak artifact is often problematic in patients with postsurgical changes or implanted hardware. Additionally, in extremely obese patients, the signal-to-noise ratio becomes somewhat prohibitive. Evaluation of densely calcified vessels can be difficult with CTA because of the similar density between plaque and contrast and the blooming artifact created by the former, leading to overestimation of the degree of stenosis in many cases, as well as the inability to determine patency in stented vessels. Because of the density of calcified plaque in relation to the relatively small lumen of the tibial vessels, CTA has traditionally suffered in the infrageniculate distribution [34]. Multiple studies have now validated dual-energy CTA as a practical and effective method for subtraction of calcified plaque and soft tissues, allowing for simultaneous creation of conventional CTA data sets and angiogram-like composite images of the vasculature alone.

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Lower Extremity Arterial Revascularization Post Therapy Imaging

These subtraction images have been demonstrated to be nearly equivalent in diagnostic accuracy to those of conventional angiograms, with similar or less radiation using newer protocols [35]. This technique has been improved at some institutions by subtracting the extravascular tissues in multiple segments rather than the entire study at once [36]. Relatively recent advances in CTA technology include the use of dynamic (time-resolved) imaging of the tibial arteries [37], selective ultra- low-dose intra-arterial contrast-enhanced CTA [38], and CO2-enhanced high-pitch CTA [39], all of which show promise in certain circumstances. MRA MRA has been used for many years in patients with PAD for both treatment planning and assessment of procedural success. Continued evolution of this technology and imaging protocols has improved image quality and increased the potential applications. Most MRA protocols provide both source images with excellent soft- tissue differentiation and subtracted images demonstrating the vasculature in 2-D and 3-D representations similar to those provided during conventional angiography. In the current era, the accuracy of CTA and CE-MRA for the detection of hemodynamically significant PAD has become essentially equivalent, with an edge for CTA in the aortoiliac segment and for MRA in the infrageniculate distribution [32]. In diabetics, MRA is considered particularly helpful for runoff evaluation because of its superior ability to detect flow in small, calcified vessels, approaching the sensitivity of digital subtraction angiography (DSA) [40]. Lower Extremity Arterial Revascularization at which each segment is optimally opacified [42]. This technique increases sensitivity, specificity, and accuracy for PAD in all segments of the lower extremity arteries, but most importantly below the knee [43,44]. Time- resolved imaging of the whole limb has also been reported [45].

Lower Extremity Arterial Revascularization Post Therapy Imaging. These subtraction images have been demonstrated to be nearly equivalent in diagnostic accuracy to those of conventional angiograms, with similar or less radiation using newer protocols [35]. This technique has been improved at some institutions by subtracting the extravascular tissues in multiple segments rather than the entire study at once [36]. Relatively recent advances in CTA technology include the use of dynamic (time-resolved) imaging of the tibial arteries [37], selective ultra- low-dose intra-arterial contrast-enhanced CTA [38], and CO2-enhanced high-pitch CTA [39], all of which show promise in certain circumstances. MRA MRA has been used for many years in patients with PAD for both treatment planning and assessment of procedural success. Continued evolution of this technology and imaging protocols has improved image quality and increased the potential applications. Most MRA protocols provide both source images with excellent soft- tissue differentiation and subtracted images demonstrating the vasculature in 2-D and 3-D representations similar to those provided during conventional angiography. In the current era, the accuracy of CTA and CE-MRA for the detection of hemodynamically significant PAD has become essentially equivalent, with an edge for CTA in the aortoiliac segment and for MRA in the infrageniculate distribution [32]. In diabetics, MRA is considered particularly helpful for runoff evaluation because of its superior ability to detect flow in small, calcified vessels, approaching the sensitivity of digital subtraction angiography (DSA) [40]. Lower Extremity Arterial Revascularization at which each segment is optimally opacified [42]. This technique increases sensitivity, specificity, and accuracy for PAD in all segments of the lower extremity arteries, but most importantly below the knee [43,44]. Time- resolved imaging of the whole limb has also been reported [45].

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MRA provides imaging quality similar to DSA for the evaluation of lower extremity bypass conduits [46,47]. It also allows for excellent evaluation of previously angioplastied segments and has a high specificity for in-stent patency; however, sensitivity for occlusion is still poor because of blooming artifact, particularly in stainless steel stents [48]. Newer generation nitinol stents are less affected by this limitation. There are several important limitations of MRA. Patients with most types of defibrillators, spinal cord stimulators, intracerebral shunts, cochlear implants, and other devices are excluded, as are patients affected by claustrophobia that is not overcome by sedation. Open-field 1.0T MRA has been used for claustrophobic patients, with imaging quality approaching that of DSA above the knee; however, below the knee, the technology is still quite limited [49]. It takes longer to acquire images with MRA than with CTA, and the studies themselves are considerably more expensive. However, with MRA, patients are not exposed to ionizing radiation, and the risk of nephrotoxicity from gadolinium-based contrast is considerably less than that of iodinated contrast agents. For a time, CE-MRA was considered an alternative to CTA in patients with renal impairment; however, since the association between renal failure and nephrogenic systemic fibrosis after gadolinium administration was discovered, it fell out of favor [50]. This led to copious research of noncontrast MRA. Time-of-flight imaging is one such method, which, with current technology, provides images with equivalent accuracy to CE-MRA for popliteal and runoff assessment, but still lags behind in the aortoiliac and femoral segments [51,52]. It is less expensive than CE-MRA, and has been proposed as a potential PAD screening test [53].

Lower Extremity Arterial Revascularization Post Therapy Imaging. MRA provides imaging quality similar to DSA for the evaluation of lower extremity bypass conduits [46,47]. It also allows for excellent evaluation of previously angioplastied segments and has a high specificity for in-stent patency; however, sensitivity for occlusion is still poor because of blooming artifact, particularly in stainless steel stents [48]. Newer generation nitinol stents are less affected by this limitation. There are several important limitations of MRA. Patients with most types of defibrillators, spinal cord stimulators, intracerebral shunts, cochlear implants, and other devices are excluded, as are patients affected by claustrophobia that is not overcome by sedation. Open-field 1.0T MRA has been used for claustrophobic patients, with imaging quality approaching that of DSA above the knee; however, below the knee, the technology is still quite limited [49]. It takes longer to acquire images with MRA than with CTA, and the studies themselves are considerably more expensive. However, with MRA, patients are not exposed to ionizing radiation, and the risk of nephrotoxicity from gadolinium-based contrast is considerably less than that of iodinated contrast agents. For a time, CE-MRA was considered an alternative to CTA in patients with renal impairment; however, since the association between renal failure and nephrogenic systemic fibrosis after gadolinium administration was discovered, it fell out of favor [50]. This led to copious research of noncontrast MRA. Time-of-flight imaging is one such method, which, with current technology, provides images with equivalent accuracy to CE-MRA for popliteal and runoff assessment, but still lags behind in the aortoiliac and femoral segments [51,52]. It is less expensive than CE-MRA, and has been proposed as a potential PAD screening test [53].

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Quiescent-interval single-shot MRA and flow-spoiled fresh-blood imaging are newer techniques, which may show promise in combination with conventional time-of-flight techniques [54-56]. Quiescent-interval single-shot currently provides similar imaging quality and diagnostic accuracy to CE-MRA in runoff vessels of diabetics, suggesting that perhaps a combination of noncontrast MRA techniques may provide equivalent whole-body vascular imaging to those provided by CE-MRA [57]. Many newer techniques in MRA show excellent promise in certain circumstances. Perfusion imaging using arterial spin labeling has been used to quantify arterial flow in the thigh and calf musculature, which has been shown to have equal or greater sensitivity for PAD compared with ABI, independent of the amount of preimaging exercise time [58,59]. Arterial peak flow velocity measurements can be obtained using phase-contrast techniques, comparing well to those obtained using spectral Doppler [60,61]. The vessel wall itself can be evaluated using blood-suppression, allowing for quantification and characterization of plaque and restenosis [62]. Continuous table movement MRA is a newer method that promises similar imaging quality to conventional multi-station MRA, with 30% faster imaging acquisition [63]. Arteriography DSA is the reference standard to which CTA and MRA are compared. DSA can localize and quantify obstructive lesions, permits physiological evaluation by the determination of pressure gradients, and allows for intervention at the time of diagnosis. In high-acuity settings, such as a thrombosed bypass graft, where immediate catheter-based intervention is likely to be indicated, direct referral to catheter angiography is a valid option. However, DSA is an invasive technique with a small but definite risk in every patient.

Lower Extremity Arterial Revascularization Post Therapy Imaging. Quiescent-interval single-shot MRA and flow-spoiled fresh-blood imaging are newer techniques, which may show promise in combination with conventional time-of-flight techniques [54-56]. Quiescent-interval single-shot currently provides similar imaging quality and diagnostic accuracy to CE-MRA in runoff vessels of diabetics, suggesting that perhaps a combination of noncontrast MRA techniques may provide equivalent whole-body vascular imaging to those provided by CE-MRA [57]. Many newer techniques in MRA show excellent promise in certain circumstances. Perfusion imaging using arterial spin labeling has been used to quantify arterial flow in the thigh and calf musculature, which has been shown to have equal or greater sensitivity for PAD compared with ABI, independent of the amount of preimaging exercise time [58,59]. Arterial peak flow velocity measurements can be obtained using phase-contrast techniques, comparing well to those obtained using spectral Doppler [60,61]. The vessel wall itself can be evaluated using blood-suppression, allowing for quantification and characterization of plaque and restenosis [62]. Continuous table movement MRA is a newer method that promises similar imaging quality to conventional multi-station MRA, with 30% faster imaging acquisition [63]. Arteriography DSA is the reference standard to which CTA and MRA are compared. DSA can localize and quantify obstructive lesions, permits physiological evaluation by the determination of pressure gradients, and allows for intervention at the time of diagnosis. In high-acuity settings, such as a thrombosed bypass graft, where immediate catheter-based intervention is likely to be indicated, direct referral to catheter angiography is a valid option. However, DSA is an invasive technique with a small but definite risk in every patient.

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Access-site hematoma, arterial dissection, thrombosis, and limb loss are known complications that can result from the procedure and occur in up to 2.0% of patients in this population [64]. These occur less frequently with increasing operator experience. For this document, it is assumed the procedure is performed and interpreted by an expert. Serious systemic complications are also possible, with increased risk in patients with severe widespread vascular disease, diabetes, renal insufficiency, or other contraindications to the use of iodinated contrast media. Carbon dioxide angiography may be of value in these patients. In light of the risk of nephrogenic systemic fibrosis in patients with severe renal disease, gadolinium chelates serve a very limited role as DSA contrast agents. Although DSA remains the gold standard for diagnosing PAD at the time of intervention, it generally plays no role in the surveillance of arterial segments previously treated with endovascular methods and in grafts without clinical evidence of malfunction. Discussion of Procedures by Variant Variant 1: Previous infrainguinal endovascular therapy or bypass. Asymptomatic. Surveillance. The most important indicator of restenosis or occlusion in the setting of previous revascularization is recurrence of symptoms. There is limited data to suggest that treatment of asymptomatic patients after endovascular therapy Lower Extremity Arterial Revascularization provides any long-term benefit [65]. As such, patients presenting to the clinic for follow-up of previous endovascular therapy or bypass for PAD should be evaluated for symptoms of claudication and rest pain, and should be examined closely for evidence of lower extremity ulceration or gangrene. ABI should be determined at each follow-up visit in all previously treated patients with PAD [66].

Lower Extremity Arterial Revascularization Post Therapy Imaging. Access-site hematoma, arterial dissection, thrombosis, and limb loss are known complications that can result from the procedure and occur in up to 2.0% of patients in this population [64]. These occur less frequently with increasing operator experience. For this document, it is assumed the procedure is performed and interpreted by an expert. Serious systemic complications are also possible, with increased risk in patients with severe widespread vascular disease, diabetes, renal insufficiency, or other contraindications to the use of iodinated contrast media. Carbon dioxide angiography may be of value in these patients. In light of the risk of nephrogenic systemic fibrosis in patients with severe renal disease, gadolinium chelates serve a very limited role as DSA contrast agents. Although DSA remains the gold standard for diagnosing PAD at the time of intervention, it generally plays no role in the surveillance of arterial segments previously treated with endovascular methods and in grafts without clinical evidence of malfunction. Discussion of Procedures by Variant Variant 1: Previous infrainguinal endovascular therapy or bypass. Asymptomatic. Surveillance. The most important indicator of restenosis or occlusion in the setting of previous revascularization is recurrence of symptoms. There is limited data to suggest that treatment of asymptomatic patients after endovascular therapy Lower Extremity Arterial Revascularization provides any long-term benefit [65]. As such, patients presenting to the clinic for follow-up of previous endovascular therapy or bypass for PAD should be evaluated for symptoms of claudication and rest pain, and should be examined closely for evidence of lower extremity ulceration or gangrene. ABI should be determined at each follow-up visit in all previously treated patients with PAD [66].

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PVRs can provide insight into subtle changes in arterial flow quality between segments, often preceding detectable anatomic changes on other modalities; however, they are fraught with reader subjectivity, poor patient cooperation, and baseline abnormalities in poor cardiac output [9]. A recent paper has also called into question whether they provide any benefit over ABIs and SPMs alone [67]. MRA Although both CE-MRA and nonenhanced MRA have been proposed as potential screening tests for PAD, particularly in patients in whom NIVT is limited (ie, diabetics) and time constraints remain prohibitive [77], there is no convincing evidence in the literature arguing for the use of CE-MRA or nonenhanced MRA for surveillance of previously treated PAD, either with endovascular or surgical methods. False positives suggesting recurrent disease in asymptomatic patients could lead to unnecessary procedures. CTA Because of availability, the use of ionizing radiation and the risks inherent to iodinated contrast, CTA is not recommended for routine follow-up of asymptomatic patients with nonaneurysmal PAD. Arteriography As an invasive test, lower extremity arteriography is completely inappropriate for surveillance of asymptomatic patients. There is no evidence to support its use in this setting. Lower Extremity Arterial Revascularization US DUS has a very high correlation with clinical deterioration after both endovascular therapy and bypass for lower-extremity PAD [26]. Following angioplasty, DUS has been validated as accurate for determining the specific levels of hemodynamically significant disease, although it often underestimates the extent of disease beyond the first significant stenosis. The aortoiliac segment can be evaluated in some patients, although obesity and bowel gas artifact are a pervasive problem.

Lower Extremity Arterial Revascularization Post Therapy Imaging. PVRs can provide insight into subtle changes in arterial flow quality between segments, often preceding detectable anatomic changes on other modalities; however, they are fraught with reader subjectivity, poor patient cooperation, and baseline abnormalities in poor cardiac output [9]. A recent paper has also called into question whether they provide any benefit over ABIs and SPMs alone [67]. MRA Although both CE-MRA and nonenhanced MRA have been proposed as potential screening tests for PAD, particularly in patients in whom NIVT is limited (ie, diabetics) and time constraints remain prohibitive [77], there is no convincing evidence in the literature arguing for the use of CE-MRA or nonenhanced MRA for surveillance of previously treated PAD, either with endovascular or surgical methods. False positives suggesting recurrent disease in asymptomatic patients could lead to unnecessary procedures. CTA Because of availability, the use of ionizing radiation and the risks inherent to iodinated contrast, CTA is not recommended for routine follow-up of asymptomatic patients with nonaneurysmal PAD. Arteriography As an invasive test, lower extremity arteriography is completely inappropriate for surveillance of asymptomatic patients. There is no evidence to support its use in this setting. Lower Extremity Arterial Revascularization US DUS has a very high correlation with clinical deterioration after both endovascular therapy and bypass for lower-extremity PAD [26]. Following angioplasty, DUS has been validated as accurate for determining the specific levels of hemodynamically significant disease, although it often underestimates the extent of disease beyond the first significant stenosis. The aortoiliac segment can be evaluated in some patients, although obesity and bowel gas artifact are a pervasive problem.

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In combination with spectral Doppler, inflow disease can often be excluded and can guide the interventional approach (ie, retrograde contralateral versus antegrade ipsilateral access). Duplex is valuable in the determination of flow within and beyond stented and stent-grafted segments, and is slightly less limited than CTA and MRA, particularly in smaller-caliber stents [22]. The identification and treatment of symptomatic restenosis associated with a previously treated segment has been shown to provide improved long-term outcomes and patency in both endovascular and surgical patients [79]. In many cases, patients can proceed directly to intervention with Duplex arterial mapping alone [16,17]. In the setting of bypass, Duplex can determine whether the graft is patent, threatened, or occluded, and often can identify specific segments of disease to guide either endovascular repair or surgical revision. Although nonenhanced MRA can provide imaging quality and diagnostic confidence levels similar to that from CE-MRA, protocols and image quality vary significantly between institutions. Additionally, the lack of time- resolved imaging limits evaluation in the infrageniculate segment. Its use is generally reserved for patients who require evaluation of suspected aortoiliac and femoropopliteal lesions in the setting of renal insufficiency. The use of this modality is likely to evolve over the next decade given the vast amount of research in this area over the past few years. CTA In the era of modern CTA, vascular imaging quality is similar to that of DSA, albeit with a modest limitation in the infrageniculate distribution due to contrast-timing issues and the frequency of tibial calcification. Through the acquisition of isotropic voxels on new scanners, images can be reconstructed in any plane, including curved planar reformats along the lumen of the vessel [80].

Lower Extremity Arterial Revascularization Post Therapy Imaging. In combination with spectral Doppler, inflow disease can often be excluded and can guide the interventional approach (ie, retrograde contralateral versus antegrade ipsilateral access). Duplex is valuable in the determination of flow within and beyond stented and stent-grafted segments, and is slightly less limited than CTA and MRA, particularly in smaller-caliber stents [22]. The identification and treatment of symptomatic restenosis associated with a previously treated segment has been shown to provide improved long-term outcomes and patency in both endovascular and surgical patients [79]. In many cases, patients can proceed directly to intervention with Duplex arterial mapping alone [16,17]. In the setting of bypass, Duplex can determine whether the graft is patent, threatened, or occluded, and often can identify specific segments of disease to guide either endovascular repair or surgical revision. Although nonenhanced MRA can provide imaging quality and diagnostic confidence levels similar to that from CE-MRA, protocols and image quality vary significantly between institutions. Additionally, the lack of time- resolved imaging limits evaluation in the infrageniculate segment. Its use is generally reserved for patients who require evaluation of suspected aortoiliac and femoropopliteal lesions in the setting of renal insufficiency. The use of this modality is likely to evolve over the next decade given the vast amount of research in this area over the past few years. CTA In the era of modern CTA, vascular imaging quality is similar to that of DSA, albeit with a modest limitation in the infrageniculate distribution due to contrast-timing issues and the frequency of tibial calcification. Through the acquisition of isotropic voxels on new scanners, images can be reconstructed in any plane, including curved planar reformats along the lumen of the vessel [80].

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Particularly suited for aortoiliac and femoropopliteal evaluation, CTA is an excellent choice for the evaluation of claudicants, in which tibial disease is both less frequently present and less frequently treated. Similar to MRA, it is best suited in combination with tests providing data on the hemodynamic significance of identified lesions (NIVT and DUS). Arteriography Given the similar sensitivity and specificity of MRA and CTA compared with DSA, this invasive modality is generally reserved for immediate pretreatment evaluation of PAD and is rarely used solely for diagnostic purposes. The ability to acquire pressure measurements can help determine whether a previously identified stenosis is truly hemodynamically significant, which can sometimes be difficult to determine with NIVT and DUS in the setting of multilevel disease. It is occasionally used to determine surgical targets for infrageniculate bypass in patients with densely calcified runoff vessels who are deemed to be poor endovascular candidates, although noninvasive cross-sectional imaging has essentially replaced angiography for this indication as well. Lower Extremity Arterial Revascularization Variant 3: Previous infrainguinal endovascular therapy or bypass, presenting with cold, painful extremity and diminished pulses (acute limb ischemia). Initial imaging. Physical examination is critical in suspected acute limb ischemia/threatened limb, which is, at its core, a clinical diagnosis. The temperature and appearance of the limb, absence of palpable pulses or arterial signals by Doppler, loss of sensation, and decreased or absent strength in the affected extremity all provide insight into the urgency of the event. There is little evidence regarding the use of imaging in the setting of a threatened limb, and no tests should be performed that would significantly delay therapy in a patient with impending limb loss.

Lower Extremity Arterial Revascularization Post Therapy Imaging. Particularly suited for aortoiliac and femoropopliteal evaluation, CTA is an excellent choice for the evaluation of claudicants, in which tibial disease is both less frequently present and less frequently treated. Similar to MRA, it is best suited in combination with tests providing data on the hemodynamic significance of identified lesions (NIVT and DUS). Arteriography Given the similar sensitivity and specificity of MRA and CTA compared with DSA, this invasive modality is generally reserved for immediate pretreatment evaluation of PAD and is rarely used solely for diagnostic purposes. The ability to acquire pressure measurements can help determine whether a previously identified stenosis is truly hemodynamically significant, which can sometimes be difficult to determine with NIVT and DUS in the setting of multilevel disease. It is occasionally used to determine surgical targets for infrageniculate bypass in patients with densely calcified runoff vessels who are deemed to be poor endovascular candidates, although noninvasive cross-sectional imaging has essentially replaced angiography for this indication as well. Lower Extremity Arterial Revascularization Variant 3: Previous infrainguinal endovascular therapy or bypass, presenting with cold, painful extremity and diminished pulses (acute limb ischemia). Initial imaging. Physical examination is critical in suspected acute limb ischemia/threatened limb, which is, at its core, a clinical diagnosis. The temperature and appearance of the limb, absence of palpable pulses or arterial signals by Doppler, loss of sensation, and decreased or absent strength in the affected extremity all provide insight into the urgency of the event. There is little evidence regarding the use of imaging in the setting of a threatened limb, and no tests should be performed that would significantly delay therapy in a patient with impending limb loss.

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Patients with severe ischemia, as indicated by motor loss or severe sensory deficits (Rutherford class IIb or III), should likely proceed directly to definitive therapy, usually surgical thromboembolectomy or bypass [81]. Although a full spectrum of NIVT may be too time consuming in an acutely threatened limb, the determination of the ABI and SPM can assist in the determination of both the etiology of the symptoms and can also guide the level of necessary intervention. US DUS may provide the ability to determine whether the patient has an acute event associated with a previously treated segment or not. Brief evaluation of the venous system can also exclude other potential causes for acute lower extremity ischemia, such as phlegmasia cerulea dolens. Limited US evaluation for the evaluation of bilateral common femoral patency, the determination of inflow quality, and the patency of lower extremity bypass conduits can help guide expeditious treatment. Given portability and ubiquity in the hospital system, this can potentially be performed by physicians in the emergency department to triage patients to appropriate vascular specialists [82]. For this document, it is assumed the procedure is performed and interpreted by an expert. There is increasing focus on training vascular specialists to perform point-of-care DUS to quickly determine the etiology and extent of limb ischemia during the initial consultation [83]. This is particularly true for bypass conduits, which are generally located superficially and easily assessed sonographically. However, these tests should not delay definitive therapy if it is immediately available. Arteriography Immediately threatened limbs (Rutherford class IIb and early presentations of class III) require rapid definitive therapy, and generally should proceed directly to emergency thromboembolectomy to prevent limb loss [84].

Lower Extremity Arterial Revascularization Post Therapy Imaging. Patients with severe ischemia, as indicated by motor loss or severe sensory deficits (Rutherford class IIb or III), should likely proceed directly to definitive therapy, usually surgical thromboembolectomy or bypass [81]. Although a full spectrum of NIVT may be too time consuming in an acutely threatened limb, the determination of the ABI and SPM can assist in the determination of both the etiology of the symptoms and can also guide the level of necessary intervention. US DUS may provide the ability to determine whether the patient has an acute event associated with a previously treated segment or not. Brief evaluation of the venous system can also exclude other potential causes for acute lower extremity ischemia, such as phlegmasia cerulea dolens. Limited US evaluation for the evaluation of bilateral common femoral patency, the determination of inflow quality, and the patency of lower extremity bypass conduits can help guide expeditious treatment. Given portability and ubiquity in the hospital system, this can potentially be performed by physicians in the emergency department to triage patients to appropriate vascular specialists [82]. For this document, it is assumed the procedure is performed and interpreted by an expert. There is increasing focus on training vascular specialists to perform point-of-care DUS to quickly determine the etiology and extent of limb ischemia during the initial consultation [83]. This is particularly true for bypass conduits, which are generally located superficially and easily assessed sonographically. However, these tests should not delay definitive therapy if it is immediately available. Arteriography Immediately threatened limbs (Rutherford class IIb and early presentations of class III) require rapid definitive therapy, and generally should proceed directly to emergency thromboembolectomy to prevent limb loss [84].

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In the setting of viable or marginally threatened limbs (Rutherford class I or IIa), immediate arteriography for the evaluation of anatomic relationships between diseased segments is the preferred procedure [85]. Angiography provides detailed and accurate information regarding the etiology and extent of the insult that has caused acute limb ischemia and may allow a catheter-based treatment in some patients [86]. This can allow patients to be appropriately triaged to either surgery or endovascular therapy, the latter of which may involve thrombolysis or percutaneous thrombectomy, angioplasty, stenting, etc. If performed without prior NIVT or US, there is the potential for longer procedure times, increased contrast use and possibly multiple access sites to provide definitive therapy. CTA In patients with acute limb ischemia and viable or marginally threatened limbs, CTA may be considered for preprocedural evaluation given its near-equivalent accuracy compared to diagnostic angiography [36]. CTA is a rapid modality that can provide insight into the precise location of vessel occlusion, and in some centers it is supplanting arteriography as the test of choice prior to intervention [87]. It is particularly useful in patients who present with bilateral symptoms where inflow disease is suspected. However, its use should not delay definitive therapy. Additionally, the use of iodinated contrast agent for this modality can limit the ability to provide subsequent angiographic therapy because of the risk of contrast-induced nephropathy [88]. Similar to CE-MRA, nonenhanced MRA is time consuming and should only be used in patients with renal insufficiency where the determination between endovascular and surgical therapy remains obscure. Although there are references that report on studies with design limitations, 28 well-designed or good-quality studies provide good evidence.

Lower Extremity Arterial Revascularization Post Therapy Imaging. In the setting of viable or marginally threatened limbs (Rutherford class I or IIa), immediate arteriography for the evaluation of anatomic relationships between diseased segments is the preferred procedure [85]. Angiography provides detailed and accurate information regarding the etiology and extent of the insult that has caused acute limb ischemia and may allow a catheter-based treatment in some patients [86]. This can allow patients to be appropriately triaged to either surgery or endovascular therapy, the latter of which may involve thrombolysis or percutaneous thrombectomy, angioplasty, stenting, etc. If performed without prior NIVT or US, there is the potential for longer procedure times, increased contrast use and possibly multiple access sites to provide definitive therapy. CTA In patients with acute limb ischemia and viable or marginally threatened limbs, CTA may be considered for preprocedural evaluation given its near-equivalent accuracy compared to diagnostic angiography [36]. CTA is a rapid modality that can provide insight into the precise location of vessel occlusion, and in some centers it is supplanting arteriography as the test of choice prior to intervention [87]. It is particularly useful in patients who present with bilateral symptoms where inflow disease is suspected. However, its use should not delay definitive therapy. Additionally, the use of iodinated contrast agent for this modality can limit the ability to provide subsequent angiographic therapy because of the risk of contrast-induced nephropathy [88]. Similar to CE-MRA, nonenhanced MRA is time consuming and should only be used in patients with renal insufficiency where the determination between endovascular and surgical therapy remains obscure. Although there are references that report on studies with design limitations, 28 well-designed or good-quality studies provide good evidence.

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Rib Fractures

Introduction/Background Rib fracture is the most common thoracic injury and is present in 10% of all traumatic injuries and in almost 40% of patients who sustain severe nonpenetrating trauma [1,2]. Rib fractures typically affect the fifth through ninth ribs. This may be due to the fact that the shoulder girdle affords relative protection to the upper ribs, and the lower ribs are relatively mobile and may deflect before fracturing [1]. Although rib fractures can produce significant morbidity, the diagnosis of associated complications (such as pneumothorax, hemothorax, pulmonary contusion, atelectasis, flail chest, cardiovascular injury, and injuries to solid and hollow abdominal organs) is arguably more important as these complications are likely to have the most significant clinical impact [1,2]. When isolated, rib fractures have a relatively low morbidity and mortality [2,3]. Treatment of rib fractures is generally aimed at pain control and avoidance of respiratory distress and intubation, but the presence of multiple rib fractures, underlying organ injury, or in an elderly patient especially, may warrant transfer from a community hospital to tertiary care center [2,4-6]. Radiography Chest In combination with the physical examination, a standard posteroanterior (PA) chest radiograph should be the initial diagnostic test for detection of rib fractures. Despite the low sensitivity of the chest radiograph, which may miss 50% of rib fractures [2], studies suggest that failure to detect fractures does not necessarily alter patient management or outcome in uncomplicated cases. A review of 271 patients who presented to a community hospital emergency department after minor trauma showed no difference in treatment (use of pain medications, etc) between patients who did and did not have rib fractures diagnosed on physical examination or radiographs [3].

Rib Fractures. Introduction/Background Rib fracture is the most common thoracic injury and is present in 10% of all traumatic injuries and in almost 40% of patients who sustain severe nonpenetrating trauma [1,2]. Rib fractures typically affect the fifth through ninth ribs. This may be due to the fact that the shoulder girdle affords relative protection to the upper ribs, and the lower ribs are relatively mobile and may deflect before fracturing [1]. Although rib fractures can produce significant morbidity, the diagnosis of associated complications (such as pneumothorax, hemothorax, pulmonary contusion, atelectasis, flail chest, cardiovascular injury, and injuries to solid and hollow abdominal organs) is arguably more important as these complications are likely to have the most significant clinical impact [1,2]. When isolated, rib fractures have a relatively low morbidity and mortality [2,3]. Treatment of rib fractures is generally aimed at pain control and avoidance of respiratory distress and intubation, but the presence of multiple rib fractures, underlying organ injury, or in an elderly patient especially, may warrant transfer from a community hospital to tertiary care center [2,4-6]. Radiography Chest In combination with the physical examination, a standard posteroanterior (PA) chest radiograph should be the initial diagnostic test for detection of rib fractures. Despite the low sensitivity of the chest radiograph, which may miss 50% of rib fractures [2], studies suggest that failure to detect fractures does not necessarily alter patient management or outcome in uncomplicated cases. A review of 271 patients who presented to a community hospital emergency department after minor trauma showed no difference in treatment (use of pain medications, etc) between patients who did and did not have rib fractures diagnosed on physical examination or radiographs [3].

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Rib Fractures

In a study of 552 patients who had blunt chest trauma and resultant rib fracture (diagnosed on clinical or radiographic grounds), 93% of affected patients ultimately resumed daily activities without significant disability [2]. The chest radiograph may detect complications that are more important than the rib fractures themselves, such as pneumothorax, hemothorax, flail chest, or contusion [1,2]. Although a flail chest can usually be diagnosed at physical examination, it is conceivable that in a heavy patient a flail chest could be missed by clinical examination, but a chest radiograph almost always shows the displaced fragments. Dual-energy chest radiography with bone subtraction imaging has failed to show improved detection when aPanel Vice-Chair, University of California San Francisco, San Francisco, California. bPanel Chair, Vanderbilt University Medical Center, Nashville, Tennessee. cCharles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, Florida. dSouthern Illinois University School of Medicine, Springfield, Illinois; Society of Thoracic Surgeons. eUniversity of Iowa, Iowa City, Iowa; Society of Thoracic Surgeons. fMayo Clinic, Rochester, Minnesota. gUniversity of Michigan Medical Center, Ann Arbor, Michigan. hUniversity of Iowa Hospitals and Clinics, Iowa City, Iowa. iVanderbilt University Medical Center, Nashville, Tennessee; American College of Chest Physicians. jRadiology Imaging Associates, Englewood, Colorado. kUniversity of Texas Health Science Center at San Antonio, San Antonio, Texas. lJohn H. Stroger, Jr. Hospital of Cook County, Chicago, Illinois; American College of Physicians. mNational Institutes of Health, Bethesda, Maryland. nUniversity of Texas MD Anderson Cancer Center, Houston, Texas. oSpecialty Chair, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin. Reprint requests to: [email protected] Rib Fractures compared with standard radiographs.

Rib Fractures. In a study of 552 patients who had blunt chest trauma and resultant rib fracture (diagnosed on clinical or radiographic grounds), 93% of affected patients ultimately resumed daily activities without significant disability [2]. The chest radiograph may detect complications that are more important than the rib fractures themselves, such as pneumothorax, hemothorax, flail chest, or contusion [1,2]. Although a flail chest can usually be diagnosed at physical examination, it is conceivable that in a heavy patient a flail chest could be missed by clinical examination, but a chest radiograph almost always shows the displaced fragments. Dual-energy chest radiography with bone subtraction imaging has failed to show improved detection when aPanel Vice-Chair, University of California San Francisco, San Francisco, California. bPanel Chair, Vanderbilt University Medical Center, Nashville, Tennessee. cCharles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, Florida. dSouthern Illinois University School of Medicine, Springfield, Illinois; Society of Thoracic Surgeons. eUniversity of Iowa, Iowa City, Iowa; Society of Thoracic Surgeons. fMayo Clinic, Rochester, Minnesota. gUniversity of Michigan Medical Center, Ann Arbor, Michigan. hUniversity of Iowa Hospitals and Clinics, Iowa City, Iowa. iVanderbilt University Medical Center, Nashville, Tennessee; American College of Chest Physicians. jRadiology Imaging Associates, Englewood, Colorado. kUniversity of Texas Health Science Center at San Antonio, San Antonio, Texas. lJohn H. Stroger, Jr. Hospital of Cook County, Chicago, Illinois; American College of Physicians. mNational Institutes of Health, Bethesda, Maryland. nUniversity of Texas MD Anderson Cancer Center, Houston, Texas. oSpecialty Chair, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin. Reprint requests to: [email protected] Rib Fractures compared with standard radiographs.

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Rib Fractures

A review of 39 patients with a total of 204 rib fractures showed no statistically significant difference in sensitivity, specificity, or level of confidence between standard images and dual-energy subtraction images [9]. Radiography Rib Views While still performed in many practices, rib detail radiograph series rarely add additional information to the PA film that would change treatment as has been shown in two retrospective studies. In a review of 422 patients presenting to a university-affiliated emergency department for suspected rib fracture, Shuaib et al [10] found that rib series resulted in a change of management in only one patient (0.23%). Moreover, these authors found that, compared to standard PA radiographs, rib series negatively impacted patient care by prolonging report turnaround time [10]. Hoffstetter et al [11] retrospectively reviewed 609 patients that underwent rib series in the emergency department and found that while diagnosing a higher number of rib fractures as compared to PA radiographs alone, there was no statistically significant difference in the number of patients who received medical treatment. If rib series are to be performed, Park et al [12] showed that interpreting images with both conventional grayscale and inverted grayscale views may improve detection of rib fractures, although this study did not assess if the improved detection had an effect on outcomes. CT Chest The increased sensitivity of CT for the detection of rib fractures does not necessarily alter the management or clinical outcomes of patients without associated injuries. Kea et al [13] reported that CT detected rib fractures in 66 of 589 patients (11%) who had initial chest radiographs interpreted as normal at a level I trauma center, but none of the rib fractures were considered of major clinical significance. The presence and number of rib fractures, and the degree of displacement of the fractures, may carry prognostic significance.

Rib Fractures. A review of 39 patients with a total of 204 rib fractures showed no statistically significant difference in sensitivity, specificity, or level of confidence between standard images and dual-energy subtraction images [9]. Radiography Rib Views While still performed in many practices, rib detail radiograph series rarely add additional information to the PA film that would change treatment as has been shown in two retrospective studies. In a review of 422 patients presenting to a university-affiliated emergency department for suspected rib fracture, Shuaib et al [10] found that rib series resulted in a change of management in only one patient (0.23%). Moreover, these authors found that, compared to standard PA radiographs, rib series negatively impacted patient care by prolonging report turnaround time [10]. Hoffstetter et al [11] retrospectively reviewed 609 patients that underwent rib series in the emergency department and found that while diagnosing a higher number of rib fractures as compared to PA radiographs alone, there was no statistically significant difference in the number of patients who received medical treatment. If rib series are to be performed, Park et al [12] showed that interpreting images with both conventional grayscale and inverted grayscale views may improve detection of rib fractures, although this study did not assess if the improved detection had an effect on outcomes. CT Chest The increased sensitivity of CT for the detection of rib fractures does not necessarily alter the management or clinical outcomes of patients without associated injuries. Kea et al [13] reported that CT detected rib fractures in 66 of 589 patients (11%) who had initial chest radiographs interpreted as normal at a level I trauma center, but none of the rib fractures were considered of major clinical significance. The presence and number of rib fractures, and the degree of displacement of the fractures, may carry prognostic significance.

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Rib Fractures

Thus, detection of rib fractures by CT may be indicated under certain circumstances (especially if severe injury is suspected). Bugaev et al [14] retrospectively reviewed 245 patients that presented to a level 1 trauma center for a number of rib fractures and degree of displacement. They found that the number of rib fractures and the degree of fracture fragment displacement accurately predicted subsequent opioid requirements. Patients with rib fractures from a high-energy mechanism or with a high clinical suspicion of intrathoracic or intra-abdominal injury may warrant further evaluation with contrast-enhanced CT, whereas a low-energy injury or normal physical examination may obviate further testing. Dubinsky and Low [17] studied 69 patients with nonthreatening trauma (stable vital signs with no evidence of cardiac injury, solid or hollow viscus rupture, or fractures associated with significant blood loss) and found that neither rib studies nor chest radiographs were of clinical benefit in this scenario, but they concluded that clinical evidence of a complicated injury, such as pneumothorax, hemothorax, or flail chest, may warrant further evaluation. Similarly, Schurink et al [18] studied patients with lower rib fractures (ribs 7 through 12) and found that the negative predictive value of a negative physical examination for abdominal injury that is due to low-energy impact was 100%, but in patients with multiple injuries, lower rib fractures were associated with abdominal organ injury in 67% of patients. Matthes et al [19] found no association between right-sided lower rib fractures in 55 Rib Fractures trauma patients with hepatic injury when matched with 55 trauma patients without hepatic injury (there was a slight negative association of hepatic laceration with left-sided fractures) but ultimately concluded that the absence of rib fractures could not rule out hepatic injury.

Rib Fractures. Thus, detection of rib fractures by CT may be indicated under certain circumstances (especially if severe injury is suspected). Bugaev et al [14] retrospectively reviewed 245 patients that presented to a level 1 trauma center for a number of rib fractures and degree of displacement. They found that the number of rib fractures and the degree of fracture fragment displacement accurately predicted subsequent opioid requirements. Patients with rib fractures from a high-energy mechanism or with a high clinical suspicion of intrathoracic or intra-abdominal injury may warrant further evaluation with contrast-enhanced CT, whereas a low-energy injury or normal physical examination may obviate further testing. Dubinsky and Low [17] studied 69 patients with nonthreatening trauma (stable vital signs with no evidence of cardiac injury, solid or hollow viscus rupture, or fractures associated with significant blood loss) and found that neither rib studies nor chest radiographs were of clinical benefit in this scenario, but they concluded that clinical evidence of a complicated injury, such as pneumothorax, hemothorax, or flail chest, may warrant further evaluation. Similarly, Schurink et al [18] studied patients with lower rib fractures (ribs 7 through 12) and found that the negative predictive value of a negative physical examination for abdominal injury that is due to low-energy impact was 100%, but in patients with multiple injuries, lower rib fractures were associated with abdominal organ injury in 67% of patients. Matthes et al [19] found no association between right-sided lower rib fractures in 55 Rib Fractures trauma patients with hepatic injury when matched with 55 trauma patients without hepatic injury (there was a slight negative association of hepatic laceration with left-sided fractures) but ultimately concluded that the absence of rib fractures could not rule out hepatic injury.

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Thus, in patients with multiple injuries and lower rib fractures, contrast-enhanced CT might be indicated even in the setting of a normal clinical examination. Several studies have demonstrated a high prevalence of radiographically detected rib fractures in patients with aortic injury, although the positive predictive value is low. In a large prospective multicenter trial involving 50 trauma centers in North America, Fabian et al [20] reported multiple rib fractures in 46% of 274 patients with blunt aortic injury. Mirvis et al [21] found fractures of ribs 1 through 4 in 18% of 41 patients with traumatic aortic injury proved by angiography but with a positive predictive value of only about 21%. Lee et al [22] studied 548 patients who underwent angiography to evaluate for aortic injury and concluded that rib fractures were the only type of thoracic skeletal injury that had a higher incidence in patients with aortic injury (58%) versus those without aortic injury (43%), but the positive predictive value was only 14.8%. This has also been shown at autopsy, where Williams et al [23] retrospectively reviewed 530 motor vehicle fatalities. In 90 victims, 105 aortic injuries were found, and 78% had multiple rib fractures, including 42% with fractures of the first rib. In contrast, there is some evidence that rib fractures detected with CT (given the increased sensitivity) may not be associated with an increased risk of aortic injury. A review of 185 patients with rib fractures detected on spine CT found no association between presence of first-rib or second-rib fracture and the incidence of aortic injury on subsequent CT [24]; however, ribs 3 through 12 were not assessed. Increased likelihood of injury to the adjacent subclavian and innominate vessels has been reported with displaced first-rib and second-rib fractures, but this injury can usually be suspected on clinical grounds or from a chest radiograph [25].

Rib Fractures. Thus, in patients with multiple injuries and lower rib fractures, contrast-enhanced CT might be indicated even in the setting of a normal clinical examination. Several studies have demonstrated a high prevalence of radiographically detected rib fractures in patients with aortic injury, although the positive predictive value is low. In a large prospective multicenter trial involving 50 trauma centers in North America, Fabian et al [20] reported multiple rib fractures in 46% of 274 patients with blunt aortic injury. Mirvis et al [21] found fractures of ribs 1 through 4 in 18% of 41 patients with traumatic aortic injury proved by angiography but with a positive predictive value of only about 21%. Lee et al [22] studied 548 patients who underwent angiography to evaluate for aortic injury and concluded that rib fractures were the only type of thoracic skeletal injury that had a higher incidence in patients with aortic injury (58%) versus those without aortic injury (43%), but the positive predictive value was only 14.8%. This has also been shown at autopsy, where Williams et al [23] retrospectively reviewed 530 motor vehicle fatalities. In 90 victims, 105 aortic injuries were found, and 78% had multiple rib fractures, including 42% with fractures of the first rib. In contrast, there is some evidence that rib fractures detected with CT (given the increased sensitivity) may not be associated with an increased risk of aortic injury. A review of 185 patients with rib fractures detected on spine CT found no association between presence of first-rib or second-rib fracture and the incidence of aortic injury on subsequent CT [24]; however, ribs 3 through 12 were not assessed. Increased likelihood of injury to the adjacent subclavian and innominate vessels has been reported with displaced first-rib and second-rib fractures, but this injury can usually be suspected on clinical grounds or from a chest radiograph [25].

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Rib Fractures

US Chest Several articles have noted that ultrasound (US) can detect fractures not seen on conventional radiographs [26- 28]. Griffith et al [28] compared US and radiography (chest radiography plus one oblique rib radiograph) in 50 patients and found that radiographs detected only 8 of 83 (10%) sonographically detected rib fractures and were positive in only 6 of the 39 patients who had demonstrated fractures. In this study, US allowed evaluation of the costochondral junction, the costal cartilage, and the ribs and was able to show nondisplaced fractures. Kara et al [26] found rib fractures in 40.5% of 37 patients with minor blunt chest trauma and negative radiographs by using US; osseous fractures were more common in the elderly, and duration of pain was significantly longer in these patients compared to those with chondral injuries [26-28]. However, Hurley et al [29] found US to be only marginally superior to conventional radiographs, and its routine use was not indicated because of the lengthy time of the examination, averaging 13 minutes in this series, and patient discomfort from the pressure of the US probe, particularly since identification of the fracture was unlikely to impact patient care. Bone Scan Whole Body Nuclear medicine bone scans are sensitive but not specific for detection of rib fracture [30]. Bone scans are most commonly used for detection of osseous involvement in systemic processes (eg, metastatic disease) and may result in false-positive diagnosis of malignancy in a patient with rib fractures, although the pattern of tracer uptake can often help differentiate the two processes [30]. Bone scans have limited use in distinguishing acute and subacute or chronic rib fractures as they will usually be positive within 24 hours after an injury, but the return to normal can be slow (79% by 1 year, 93% by 2 years, and 100% in 3 years) [31].

Rib Fractures. US Chest Several articles have noted that ultrasound (US) can detect fractures not seen on conventional radiographs [26- 28]. Griffith et al [28] compared US and radiography (chest radiography plus one oblique rib radiograph) in 50 patients and found that radiographs detected only 8 of 83 (10%) sonographically detected rib fractures and were positive in only 6 of the 39 patients who had demonstrated fractures. In this study, US allowed evaluation of the costochondral junction, the costal cartilage, and the ribs and was able to show nondisplaced fractures. Kara et al [26] found rib fractures in 40.5% of 37 patients with minor blunt chest trauma and negative radiographs by using US; osseous fractures were more common in the elderly, and duration of pain was significantly longer in these patients compared to those with chondral injuries [26-28]. However, Hurley et al [29] found US to be only marginally superior to conventional radiographs, and its routine use was not indicated because of the lengthy time of the examination, averaging 13 minutes in this series, and patient discomfort from the pressure of the US probe, particularly since identification of the fracture was unlikely to impact patient care. Bone Scan Whole Body Nuclear medicine bone scans are sensitive but not specific for detection of rib fracture [30]. Bone scans are most commonly used for detection of osseous involvement in systemic processes (eg, metastatic disease) and may result in false-positive diagnosis of malignancy in a patient with rib fractures, although the pattern of tracer uptake can often help differentiate the two processes [30]. Bone scans have limited use in distinguishing acute and subacute or chronic rib fractures as they will usually be positive within 24 hours after an injury, but the return to normal can be slow (79% by 1 year, 93% by 2 years, and 100% in 3 years) [31].

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Rib Fractures

Furthermore, patients with known malignancy and benign rib fractures may exhibit false-positive findings on PET using the tracer fluorine- 18-2-fluoro-2-deoxy-D- glucose (FDG) studies performed 17 days to 8 weeks after injury [32]. Variant 2: Suspected rib fractures after cardiopulmonary resuscitation (CPR). Initial imaging. Radiography Chest Multiple studies [33-35] have shown that rib fractures are under-reported on radiography performed following cardiopulmonary resuscitation (CPR). In a retrospective analysis of 40 patients who survived CPR, Kim et al [33] reported that CT detected rib fractures in 26 patients (65%); whereas, anteroposterior chest radiography detected fractures in only 10 of the patients. Lederer et al [34] found that radiography detected only 14% of rib fractures compared to autopsy in 19 patients. Rib fractures from CPR are more commonly anterior, on the left side, and are more numerous in the elderly [34]. The diagnosis of such fractures in CPR survivors may be important since approximately half of CPR survivors with rib fractures experience complications, and the presence of rib fractures in these patients may impair Rib Fractures ventilation and compromise recovery. It should be noted that many of these patients are examined with portable supine radiography, which may contribute to underdiagnosis. Radiography Rib Views There is no strong indication in the literature that radiography rib series serves any significant use as an initial imaging modality to detect rib fractures after CPR. US Chest While focused US of the chest wall is more sensitive for detection of rib fractures than radiography in trauma patients [28], there is no direct evidence assessing the use of US in patients after CPR. Bone Scan Whole Body There is no strong indication in the literature that bone scan serves any significant use as an initial imaging modality to detect rib fractures after CPR.

Rib Fractures. Furthermore, patients with known malignancy and benign rib fractures may exhibit false-positive findings on PET using the tracer fluorine- 18-2-fluoro-2-deoxy-D- glucose (FDG) studies performed 17 days to 8 weeks after injury [32]. Variant 2: Suspected rib fractures after cardiopulmonary resuscitation (CPR). Initial imaging. Radiography Chest Multiple studies [33-35] have shown that rib fractures are under-reported on radiography performed following cardiopulmonary resuscitation (CPR). In a retrospective analysis of 40 patients who survived CPR, Kim et al [33] reported that CT detected rib fractures in 26 patients (65%); whereas, anteroposterior chest radiography detected fractures in only 10 of the patients. Lederer et al [34] found that radiography detected only 14% of rib fractures compared to autopsy in 19 patients. Rib fractures from CPR are more commonly anterior, on the left side, and are more numerous in the elderly [34]. The diagnosis of such fractures in CPR survivors may be important since approximately half of CPR survivors with rib fractures experience complications, and the presence of rib fractures in these patients may impair Rib Fractures ventilation and compromise recovery. It should be noted that many of these patients are examined with portable supine radiography, which may contribute to underdiagnosis. Radiography Rib Views There is no strong indication in the literature that radiography rib series serves any significant use as an initial imaging modality to detect rib fractures after CPR. US Chest While focused US of the chest wall is more sensitive for detection of rib fractures than radiography in trauma patients [28], there is no direct evidence assessing the use of US in patients after CPR. Bone Scan Whole Body There is no strong indication in the literature that bone scan serves any significant use as an initial imaging modality to detect rib fractures after CPR.

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Rib Fractures

CT Chest As described above, chest CT is more sensitive than radiography for the detection of rib fractures after CPR. Moreover, CT may show fracture-related complications that are radiographically occult. Kim et al [33] reported that CT found fracture-related complications in 6 of 40 patients (15%) who received CPR, including 1 pneumothorax, 1 subclavian vein injury, and 4 chest wall hematomas. This study did not indicate whether intravenous (IV) contrast was used, nor did it indicate whether CT was performed specifically for evaluation of rib fractures, or if the rib fractures were an incidental finding on a CT performed for other means (eg, suspected pulmonary embolism). Variant 3: Suspected pathologic rib fracture. Initial imaging. Radiography Chest Pathologic fractures may result from metabolic disorders or neoplasm, including primary bone tumor, metastatic disease of intrathoracic or extrathoracic primary, hematologic malignancy (eg, multiple myeloma, lymphoma), or direct extension of a tumor in the thorax. A PA chest radiograph may be sufficient for diagnosis of a pathologic fracture (or provide clues to an underlying diagnosis), but further evaluation using such modalities as CT, bone scan, or FDG-PET may be necessary to further characterize a lesion detected on radiography or to search for radiographically occult lesions [36-38]. Radiography Rib Views There is no strong indication in the literature that radiography rib series serves any significant use as an initial imaging modality to detect suspected pathologic rib fractures. US Chest There is no strong indication in the literature that US serves any significant use as an initial imaging modality to detect rib fractures. CT Chest CT may be useful for characterizing a pathologic fracture, and some features may be helpful in differentiating a primary malignant tumor of bone from metastasis [36].

Rib Fractures. CT Chest As described above, chest CT is more sensitive than radiography for the detection of rib fractures after CPR. Moreover, CT may show fracture-related complications that are radiographically occult. Kim et al [33] reported that CT found fracture-related complications in 6 of 40 patients (15%) who received CPR, including 1 pneumothorax, 1 subclavian vein injury, and 4 chest wall hematomas. This study did not indicate whether intravenous (IV) contrast was used, nor did it indicate whether CT was performed specifically for evaluation of rib fractures, or if the rib fractures were an incidental finding on a CT performed for other means (eg, suspected pulmonary embolism). Variant 3: Suspected pathologic rib fracture. Initial imaging. Radiography Chest Pathologic fractures may result from metabolic disorders or neoplasm, including primary bone tumor, metastatic disease of intrathoracic or extrathoracic primary, hematologic malignancy (eg, multiple myeloma, lymphoma), or direct extension of a tumor in the thorax. A PA chest radiograph may be sufficient for diagnosis of a pathologic fracture (or provide clues to an underlying diagnosis), but further evaluation using such modalities as CT, bone scan, or FDG-PET may be necessary to further characterize a lesion detected on radiography or to search for radiographically occult lesions [36-38]. Radiography Rib Views There is no strong indication in the literature that radiography rib series serves any significant use as an initial imaging modality to detect suspected pathologic rib fractures. US Chest There is no strong indication in the literature that US serves any significant use as an initial imaging modality to detect rib fractures. CT Chest CT may be useful for characterizing a pathologic fracture, and some features may be helpful in differentiating a primary malignant tumor of bone from metastasis [36].

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Inflammatory Back Pain Known or Suspected Axial Spondyloarthropathy PCAs

Introduction/Background Axial spondyloarthritis or axial spondyloarthropathy (axSpA) describes a heterogeneous group of inflammatory disorders affecting the axial skeleton that were historically classified separately as ankylosing spondylitis (AS), reactive arthritis, psoriatic spondyloarthritis, enteropathic spondyloarthritis, juvenile spondyloarthritis, and undifferentiated spondyloarthritis [1]. The prevalence of axSpA is estimated to be between 0.9% to 1.4% in the United States adult population [2]. There is a genetic component to axSpA, including a strong association with HLA-B27, which is positive in 74% to 89% of patients [1]. Patients with axSpA often present before age 45 with chronic back pain and stiffness and may have elevated inflammatory markers [3]. A clinical hallmark is the presence of inflammatory back pain, which is present in 70% to 80% of patients [4]. There are varying definitions for inflammatory back pain, although characteristically this pain includes the following features: insidious onset, improvement with exercise, no improvement with rest, occurring at night, and age of onset <40 years of age [4]. Inflammatory back pain symptoms, depending on the criteria used, have been reportedly been present in 5% to 6% of the general adult population [5], and in up to 15% of patients in the primary care setting [6]. Although recognition of axSpA is improving, a mean delay of 4.9 years from onset of symptoms to diagnosis was recently reported, highlighting the challenge of establishing this diagnosis early in the disease course [7]. Imaging plays a critical role in the diagnosis of axSpA. Historically, imaging diagnosis was based on radiographs using the modified New York criteria [15]; however, the radiographic changes of axSpA were subsequently found to evolve slowly over the course of years [16,17].

Inflammatory Back Pain Known or Suspected Axial Spondyloarthropathy PCAs. Introduction/Background Axial spondyloarthritis or axial spondyloarthropathy (axSpA) describes a heterogeneous group of inflammatory disorders affecting the axial skeleton that were historically classified separately as ankylosing spondylitis (AS), reactive arthritis, psoriatic spondyloarthritis, enteropathic spondyloarthritis, juvenile spondyloarthritis, and undifferentiated spondyloarthritis [1]. The prevalence of axSpA is estimated to be between 0.9% to 1.4% in the United States adult population [2]. There is a genetic component to axSpA, including a strong association with HLA-B27, which is positive in 74% to 89% of patients [1]. Patients with axSpA often present before age 45 with chronic back pain and stiffness and may have elevated inflammatory markers [3]. A clinical hallmark is the presence of inflammatory back pain, which is present in 70% to 80% of patients [4]. There are varying definitions for inflammatory back pain, although characteristically this pain includes the following features: insidious onset, improvement with exercise, no improvement with rest, occurring at night, and age of onset <40 years of age [4]. Inflammatory back pain symptoms, depending on the criteria used, have been reportedly been present in 5% to 6% of the general adult population [5], and in up to 15% of patients in the primary care setting [6]. Although recognition of axSpA is improving, a mean delay of 4.9 years from onset of symptoms to diagnosis was recently reported, highlighting the challenge of establishing this diagnosis early in the disease course [7]. Imaging plays a critical role in the diagnosis of axSpA. Historically, imaging diagnosis was based on radiographs using the modified New York criteria [15]; however, the radiographic changes of axSpA were subsequently found to evolve slowly over the course of years [16,17].

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Inflammatory Back Pain Known or Suspected Axial Spondyloarthropathy PCAs

Additionally, some patients with symptomatic AS did not have radiographic evidence of axSpA [18], driving the search for additional imaging biomarkers of early disease. As evolving literature accumulated on the utility of MRI in axSpA, the Assessment of SpondyloArthritis international Society (ASAS) established diagnostic criteria in 2009 for axSpA that included MRI in the diagnostic algorithm, promoting the diagnosis of both patients with radiographically evident axSpA (radiographic-axSpA or classic AS) as well as patients with negative radiographs who may have inflammatory changes demonstrated on MRI (nonradiographic-axSpA) [17,19]. It was later shown that a portion of patients with nonradiographic-axSpA will Reprint requests to: [email protected] Inflammatory Back Pain progress to radiographic-axSpA over the course of years [20], although it is uncertain if radiographic-axSpA and nonradiographic-axSpA represent a continuum of the same entity or if they are truly separate disease subsets. This is the topic of some debate [1,21-23]. The development of the ASAS criteria facilitated diagnosis of patients at an earlier stage of disease and allowed more patients with axSpA to be considered for biologic therapy [17,19,22]. However, care should be taken to acknowledge that the ASAS criteria are designed for use in clinical research, not for definitive clinical diagnosis. Beyond the important roles of imaging in early diagnosis and treatment in axSpA patients, those with advanced axSpA resulting in ankylosis are a subset of patients that warrants further discussion. These patients, classically considered to have AS, develop spinal rigidity combined with osteoporosis resulting in a risk of fracture even with low energy trauma or no apparent trauma [1,31-33]. These fractures are often unstable and involve all 3 spinal columns [31,34]. The cervical spine is most frequently involved [32,33,35].

Inflammatory Back Pain Known or Suspected Axial Spondyloarthropathy PCAs. Additionally, some patients with symptomatic AS did not have radiographic evidence of axSpA [18], driving the search for additional imaging biomarkers of early disease. As evolving literature accumulated on the utility of MRI in axSpA, the Assessment of SpondyloArthritis international Society (ASAS) established diagnostic criteria in 2009 for axSpA that included MRI in the diagnostic algorithm, promoting the diagnosis of both patients with radiographically evident axSpA (radiographic-axSpA or classic AS) as well as patients with negative radiographs who may have inflammatory changes demonstrated on MRI (nonradiographic-axSpA) [17,19]. It was later shown that a portion of patients with nonradiographic-axSpA will Reprint requests to: [email protected] Inflammatory Back Pain progress to radiographic-axSpA over the course of years [20], although it is uncertain if radiographic-axSpA and nonradiographic-axSpA represent a continuum of the same entity or if they are truly separate disease subsets. This is the topic of some debate [1,21-23]. The development of the ASAS criteria facilitated diagnosis of patients at an earlier stage of disease and allowed more patients with axSpA to be considered for biologic therapy [17,19,22]. However, care should be taken to acknowledge that the ASAS criteria are designed for use in clinical research, not for definitive clinical diagnosis. Beyond the important roles of imaging in early diagnosis and treatment in axSpA patients, those with advanced axSpA resulting in ankylosis are a subset of patients that warrants further discussion. These patients, classically considered to have AS, develop spinal rigidity combined with osteoporosis resulting in a risk of fracture even with low energy trauma or no apparent trauma [1,31-33]. These fractures are often unstable and involve all 3 spinal columns [31,34]. The cervical spine is most frequently involved [32,33,35].

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Inflammatory Back Pain Known or Suspected Axial Spondyloarthropathy PCAs

Associated neurologic deficits have been reported in 21% to 100% of patients, and other complications reported in 84% of patients [32]. The diagnosis can be delayed in 15% to 41% of cases, and therefore, clinical suspicion for fracture must be elevated in the appropriate setting given the severity of these injuries. Many patients undergo surgical fixation of these injuries, although unfavorable outcomes with relatively high morbidity and mortality are reported [32,35]. Early use of advanced imaging modalities is crucial in these patients to facilitate a timely diagnosis. OR Discussion of Procedures by Variant Variant 1: Inflammatory back pain. Suspected axial spondyloarthritis. Initial imaging. The body regions covered in this clinical scenario are the sacroiliac joints, cervical, thoracic, and lumbar spine. These body regions might be evaluated separately or in combination as guided by physical examination findings, patient history, and other available information. Bone Scan with SPECT or SPECT/CT Sacroiliac Joints Bone scintigraphy with single-photon emission computed tomography (SPECT) or SPECT/CT is not routinely obtained as the initial imaging modality in the evaluation of suspected axSpA, and there is no relevant literature supporting its use in this setting. Bone Scan with SPECT or SPECT/CT Spine Area of Interest Bone scintigraphy with SPECT or SPECT/CT is not routinely obtained as the initial imaging modality in the evaluation of suspected axSpA, and there is no relevant literature supporting its use in this setting. CT Sacroiliac Joints CT is not routinely obtained as the initial imaging modality in the evaluation of suspected axSpA, and there is no relevant literature supporting its use in this setting. Inflammatory Back Pain CT Spine Area of Interest CT is not routinely obtained as the initial imaging modality in the evaluation of suspected axSpA, and there is no relevant literature supporting its use in this setting.

Inflammatory Back Pain Known or Suspected Axial Spondyloarthropathy PCAs. Associated neurologic deficits have been reported in 21% to 100% of patients, and other complications reported in 84% of patients [32]. The diagnosis can be delayed in 15% to 41% of cases, and therefore, clinical suspicion for fracture must be elevated in the appropriate setting given the severity of these injuries. Many patients undergo surgical fixation of these injuries, although unfavorable outcomes with relatively high morbidity and mortality are reported [32,35]. Early use of advanced imaging modalities is crucial in these patients to facilitate a timely diagnosis. OR Discussion of Procedures by Variant Variant 1: Inflammatory back pain. Suspected axial spondyloarthritis. Initial imaging. The body regions covered in this clinical scenario are the sacroiliac joints, cervical, thoracic, and lumbar spine. These body regions might be evaluated separately or in combination as guided by physical examination findings, patient history, and other available information. Bone Scan with SPECT or SPECT/CT Sacroiliac Joints Bone scintigraphy with single-photon emission computed tomography (SPECT) or SPECT/CT is not routinely obtained as the initial imaging modality in the evaluation of suspected axSpA, and there is no relevant literature supporting its use in this setting. Bone Scan with SPECT or SPECT/CT Spine Area of Interest Bone scintigraphy with SPECT or SPECT/CT is not routinely obtained as the initial imaging modality in the evaluation of suspected axSpA, and there is no relevant literature supporting its use in this setting. CT Sacroiliac Joints CT is not routinely obtained as the initial imaging modality in the evaluation of suspected axSpA, and there is no relevant literature supporting its use in this setting. Inflammatory Back Pain CT Spine Area of Interest CT is not routinely obtained as the initial imaging modality in the evaluation of suspected axSpA, and there is no relevant literature supporting its use in this setting.

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Inflammatory Back Pain Known or Suspected Axial Spondyloarthropathy PCAs

Fluoride PET/CT Skull Base to Mid-Thigh F-18-fluoride PET/CT is not routinely obtained as the initial imaging modality in the evaluation of suspected axSpA, and there is no relevant literature supporting its use in this setting. MRI Sacroiliac Joints MRI is not routinely obtained as the initial imaging modality in the evaluation of suspected axSpA; however, it is known that the inflammatory changes of sacroiliitis on MRI can precede radiographic structural findings of sacroiliitis by three to seven years [36,37], resulting in a low sensitivity of radiographs for detection of early disease [16,17]. In cases of those with a short duration of symptoms, MRI of the sacroiliac joints could be considered as the initial imaging modality [22]. MRI Spine Area of Interest MRI is not routinely obtained as the initial imaging modality in the evaluation of suspected axSpA, and there is no relevant literature supporting MRI of the spine in this setting. US Sacroiliac Joints Ultrasound (US) is not routinely obtained as the initial imaging modality in the evaluation of suspected axSpA, and there is no relevant literature supporting its use in this setting. US Spine Area of Interest US is not routinely obtained as the initial imaging modality in the evaluation of suspected axSpA, and there is no relevant literature supporting its use in this setting. Variant 2: Inflammatory back pain. Suspected axial spondyloarthritis. Additional imaging following radiographs. Next imaging study. The body regions covered in this clinical scenario are the sacroiliac joints, cervical, thoracic, and lumbar spine. These body regions might be evaluated separately or in combination as guided by physical examination findings, patient history, and other available information. Inflammatory Back Pain Bone Scan with SPECT or SPECT/CT Sacroiliac Joints Bone scintigraphy is not routinely suggested in the evaluation of patients with suspected axSpA [22].

Inflammatory Back Pain Known or Suspected Axial Spondyloarthropathy PCAs. Fluoride PET/CT Skull Base to Mid-Thigh F-18-fluoride PET/CT is not routinely obtained as the initial imaging modality in the evaluation of suspected axSpA, and there is no relevant literature supporting its use in this setting. MRI Sacroiliac Joints MRI is not routinely obtained as the initial imaging modality in the evaluation of suspected axSpA; however, it is known that the inflammatory changes of sacroiliitis on MRI can precede radiographic structural findings of sacroiliitis by three to seven years [36,37], resulting in a low sensitivity of radiographs for detection of early disease [16,17]. In cases of those with a short duration of symptoms, MRI of the sacroiliac joints could be considered as the initial imaging modality [22]. MRI Spine Area of Interest MRI is not routinely obtained as the initial imaging modality in the evaluation of suspected axSpA, and there is no relevant literature supporting MRI of the spine in this setting. US Sacroiliac Joints Ultrasound (US) is not routinely obtained as the initial imaging modality in the evaluation of suspected axSpA, and there is no relevant literature supporting its use in this setting. US Spine Area of Interest US is not routinely obtained as the initial imaging modality in the evaluation of suspected axSpA, and there is no relevant literature supporting its use in this setting. Variant 2: Inflammatory back pain. Suspected axial spondyloarthritis. Additional imaging following radiographs. Next imaging study. The body regions covered in this clinical scenario are the sacroiliac joints, cervical, thoracic, and lumbar spine. These body regions might be evaluated separately or in combination as guided by physical examination findings, patient history, and other available information. Inflammatory Back Pain Bone Scan with SPECT or SPECT/CT Sacroiliac Joints Bone scintigraphy is not routinely suggested in the evaluation of patients with suspected axSpA [22].

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