Staging of Colorectal Cancer

Staging of Colorectal Cancer. CT Colonography Virtual colonoscopy (or CT colonography) has proven to be a valid tool in identifying both primary and synchronous colonic lesions. Limited information is available regarding the performance of CT colonography for rectal cancer staging. In a study of 45 patients with low rectal adenocarcinomas, CT colonography with multiplanar reformation demonstrated 89% accuracy for T stage [27].


Staging of Colorectal Cancer

Staging of Colorectal Cancer. FDG-PET/CT Skull Base to Mid-Thigh Limited recent information is available regarding the performance of fluorine-18-2-fluoro-2-deoxy-D-glucose (FDG)-PET/CT for local rectal cancer staging. In a study of 59 patients with rectal cancer, conventional FDG- PET/CT was found to be 73.5% accurate for T stage and to have a 64.3% sensitivity and 96.7% specificity for N stage [28]. In an evaluation of 44 pathologic and 19 control lymph nodes, the standardized uptake value (SUV)max and SUVmean were significantly higher in pathological lymph nodes than in control lymph nodes [29].


Staging of Colorectal Cancer

Staging of Colorectal Cancer. When used as a preoperative tool in advanced tumors, MRI has shown high diagnostic accuracy for both initial staging to determine surgical plan and determining resectability following neoadjuvant treatment [39-43]. Studies have shown MRI sensitivities ranging from 94% to 100% and specificities from 85% to 88% in assessment of the circumferential resection margin [44,45]. Hence, MRI is valuable in predicting complete resection with negative margins. In a multicenter cohort trial evaluating the use of high-resolution MRI with a phased-array coil in determining resectability, a total of 228 patients underwent curative-intent treatment based on the MRI characterization of tumor extent, with 95.6% of patients achieving margin-negative results [40]. High-risk MRI features (EMVI, extramural tumor depth >5 mm, T4 stage, involved circumferential resection margin) may correlate with a higher risk for distant metastases [46,47]. In addition to initial staging prognostic features, MRI response to neoadjuvant treatment has been shown to be an indicator of long-term outcomes, including recurrence and survival [48-51]. Reduced field of view diffusion-weighted images (DWI) may demonstrate better image quality than full field of view DWIs [52].


Staging of Colorectal Cancer

Staging of Colorectal Cancer. For lymph node involvement, the differentiation of benign from metastatic locoregional nodes remains challenging. MRI is sensitive for detecting enlarged lymph nodes but remains nonspecific for differentiating benign from malignant nodes with accuracies ranging from 59% to 83% [32,36,53,54]. However, studies have shown high negative predictive value in the setting of node-negative determination by MRI, with negative predictive value ranging from 78% to 87% [32,36,53,54]. In a study of 60 patients with rectal cancer, 68.3% of patients with nodal metastasis were correctly identified using a size threshold of 7.2 mm, and accuracy was not improved by morphologic criteria [55]. However, in a study of 52 patients with rectal cancer, prediction of N stage was improved


Staging of Colorectal Cancer

Staging of Colorectal Cancer

Staging of Colorectal Cancer. Staging of Colorectal Cancer


Staging of Colorectal Cancer

Staging of Colorectal Cancer. by considering dimension, morphology, and signal characteristics [56]. Standardized reporting systems and templates have been shown to result in more complete MRI reports [57].


Staging of Colorectal Cancer

Staging of Colorectal Cancer. US Pelvis Transrectal TRUS has been considered the reference standard for T-stage evaluation of rectal carcinoma with rich historical evidence to support its use. TRUS is able to differentiate the layers of the rectal wall and provides high accuracy in detecting and characterizing tumors within the superficial layers of the rectal wall. Reported accuracies range between 80% and 97% for T-stage determination [58]. The T-stage accuracy for TRUS (84.6%) is far superior to that of CT (70.5%) [23]. Evaluation of the extent of the tumor infiltration into the mesorectum (differentiating minimal from advanced T3 tumors and minimal T3 from T2 tumors) is of clinical interest in determining the need for neoadjuvant treatment but remains a challenge for TRUS [59,60]. Although TRUS performs better than MRI for T1 tumors, similar for T2 and T3, it may be less accurate in characterizing locally advanced T4 tumors with a tendency to understage [36]. The use of TRUS in assigning patients to transanal endoscopic microsurgery versus traditional surgery remains controversial. Despite some authors reporting good accuracy for some T stages, a retrospective evaluation of the use of TRUS in patients selected to undergo transanal endoscopic microsurgery for presumed early-stage disease showed disappointing results with inaccurate staging seen in 44.8% of the 165 patients who underwent TRUS preoperatively (32.7% were understaged and 12.1% were overstaged) [61]. In a 2019 study of 500 patients, neither TRUS or MRI distinguished between T1 and T2 disease [62].


Staging of Colorectal Cancer

Staging of Colorectal Cancer. A significant limitation of TRUS is the limited field of view that compromises assessment of the relationship of the tumor, mesorectal tumor implants, tumor invasion in extramural vessels, and malignant nodes to the mesorectal fascia. MRI may better evaluate these findings because it offers a larger field of view. TRUS is also limited in its assessment of high rectal tumors.


Staging of Colorectal Cancer

Staging of Colorectal Cancer. CT Abdomen and Pelvis Much of the literature on CT restaging was generated more than 5 years ago, demonstrating low accuracy for T- stage re-evaluation or assessment of complete response. CT may remain helpful in limited situations to assess for resection margin, overall decrease in tumor, or interval change in node size, and may be of benefit to assess for overall tumor susceptibility to CRT, or in rare cases to detect distant metastatic disease that has developed during the course of neoadjuvant CRT. In early studies, accuracy of CT in predicting pathological T stage after radiotherapy was low (37%) but more accurate in the identification of involved circumferential resection margin (71%) [67].


Staging of Colorectal Cancer

Staging of Colorectal Cancer. Other studies demonstrated higher accuracy of T stage, up to 61% and CT correlation with pathologic tumor regression, with frequent overstaging due to residual fibrotic change that could not be distinguished from tumor on CT [68]. Nodal involvement was difficult to assess by CT, although change in nodal size could be appreciated, with one early study demonstrating a sensitivity of 56% and a specificity of 74% for nodal involvement [69].


Staging of Colorectal Cancer

Staging of Colorectal Cancer. Staging of Colorectal Cancer More recent studies have supported these earlier conclusions, noting that CT restaging was able to document overall response versus nonresponse to neoadjuvant CRT with limited ability to predict pathologic T and N stage at surgical resection; for example, a study of 270 patients receiving CT, MRI, and US restaging revealed 45% accuracy for CT in predicting specific pT stage and 66% accuracy for pN stage [70]. Two surgical cohorts concluded that local restaging CT prompted 0% to 4% change in surgical management of LARC postneoadjuvant CRT and was mostly helpful in the setting of metastatic disease [71,72].


Staging of Colorectal Cancer

Staging of Colorectal Cancer. For lymph node involvement, like all modalities that rely primarily on size as determinant of involvement (eg, TRUS and MRI), CT remains relatively nonspecific for N-stage determination. There is little agreement on the critical cut-off diameter to determine if lymph nodes are involved in the disease process before or after neoadjuvant treatment. Nodal size is not seen as a predictor of nodal status at surgery [8,23]. Accuracies for CT detection of lymph node stage range from 56% to 84% [19,20,24-26].


Staging of Colorectal Cancer

Staging of Colorectal Cancer. CT Colonography There is no relevant literature regarding the use of CT colonography in the restaging evaluation rectal cancer postneoadjuvant CRT.


Staging of Colorectal Cancer

Staging of Colorectal Cancer. FDG-PET/CT Skull Base to Mid-Thigh FDG-PET/CT has traditionally been used in initial staging of rectal cancer to further evaluate equivocal findings on CT/MRI, to definitively exclude extrahepatic metastatic disease before surgical resection/liver directed therapy, and to identify occult disease in patients with rising carcinoembryonic antigen [73,74]. It is widely considered a specific but not sensitive examination for evaluating distant rather than local disease [75].


Staging of Colorectal Cancer

Staging of Colorectal Cancer. A meta-analysis of a combined 1,262 patients with LARC in 19 studies assessed the accuracy of both local tumor restaging as well as regional nodal restaging as determined by restaging MRI compared to surgical pathology of the


Staging of Colorectal Cancer

Staging of Colorectal Cancer. Circumferential resection margin (involvement or close approximation of the tumor to the mesorectal fascia) assessment may be slightly less predictive at post-CRT MRI compared with pretreatment MRI, again likely due to overstaging by post-CRT imaging [89]. Tumor height on pre- and post-CRT MRI has shown excellent correlation with endoscopic findings, however, and sphincter involvement/distance, with IV contrast MRI, is more helpful in defining the relationship to the sphincter [90,91].


Staging of Colorectal Cancer

Staging of Colorectal Cancer. Additional studies confirming that N+ patients had significantly larger nodes than N0 patients both pre- and post- CRT used size cutoff for post-CRT ypN-stage prediction of <2.5 mm and >5mm at MRI [97-99]. Conversely, with luminal tumor apparent complete response, lymph nodes over 7 mm to 8 mm have been more strongly correlated with locoregional node positive (N+) [100,101]. MRI has demonstrated 75% sensitivity and 71% specificity in determining node positive disease [93].


Staging of Colorectal Cancer

Staging of Colorectal Cancer. More recently, change in nodal size or DWI signal on restaging MRI has shown more promise in assessment of nodal disease. Lack of a lymph node signal on DWI high b value 1,000 was associated with a sensitivity of 100% and a specificity of 14% [102]; the positive predictive value was 24%, and the negative predictive value was 100%. Although the absence of nodes at DWI is not a frequent finding, it appears to be a reliable predictor of yN0 status after CRT and may support the decision to consider organ-preservation treatment. Decreased lymph node size posttreatment is significantly associated with disease-free survival [103].


Staging of Colorectal Cancer

Staging of Colorectal Cancer. US Pelvis Transrectal A significant limitation of TRUS is the limited field of view that compromises assessment of relationship of the tumor, mesorectal tumor implants, tumor invasion in extramural vessels, and malignant nodes to the mesorectal fascia. In addition, TRUS is limited in its assessment of high rectal tumors and can only be used in nonstenotic patients.


Staging of Colorectal Cancer

Staging of Colorectal Cancer. Local tumor staging in a direct comparison of TRUS to MRI in 34 patients, TRUS was accurate in tumor restaging after neoadjuvant CRT in 60% to 62% and high-resolution MRI in 68% [104,105], with a meta-analysis


Staging of Colorectal Cancer

Staging of Colorectal Cancer


Staging of Colorectal Cancer

Staging of Colorectal Cancer. demonstrating lower diagnostic accuracy than MRI post-CRT, and a statistically significant decline in T-stage accuracy compared with pre-CRT [106]. Sensitivity for complete response on TRUS is as low as 25% with a specificity of 94% [107]. Contrast-enhanced TRUS plus elastography was shown in one study to improve post-CRT local staging to 85% [108].


Staging of Colorectal Cancer

Staging of Colorectal Cancer. Detection of lymph node involvement with TRUS is limited to mesorectal nodes in the immediate vicinity of the tumor, which limits sensitivity. The sensitivity pretreatment ranges from 45% to 74% [63,64], and overall accuracy ranges from 62% to 83% [22], and this appears to be similar and even more variable posttreatment [105]. Post-CRT TRUS presents the same limitations of distance from the tumor as at baseline [104].


Staging of Colorectal Cancer

Staging of Colorectal Cancer. Variant 3: Colorectal cancer. Staging for distant metastases. Initial imaging. In this clinical scenario, a patient has been recently diagnosed with colon or rectal cancer and presents for evaluation of metastatic disease in the chest, abdomen, and pelvis.


Staging of Colorectal Cancer

Staging of Colorectal Cancer. CT Chest, Abdomen, and Pelvis Most studies show comparable or improved sensitivity for detection of colorectal liver metastases with IV conventional extracellular gadolinium agent-enhanced MRI compared with CT [110,111]. Abdominal/pelvic CT with IV contrast has a high negative predictive value of 90% [112].


Staging of Colorectal Cancer

Staging of Colorectal Cancer. Detection of possible lung metastases is also an important part of the initial imaging evaluation of patients with colorectal carcinoma. The National Comprehensive Cancer Network recommends that patients with newly diagnosed colorectal cancer undergo staging chest CT, because staging chest CT has been shown to detect more lung metastases than chest radiography [119]. In a series of 74 patients with newly diagnosed rectal cancer who underwent both chest CT and chest radiography, 37% of patients with a normal chest radiograph had a lesion visible only on the chest CT, and 17% of these patients were found to have at least one pulmonary metastasis [119]. Among patients with potentially resectable liver metastases and a negative initial chest PET, additional imaging with a chest CT revealed pulmonary metastases in 5% of patients [120]. A potential pitfall of chest CT is the detection of small indeterminate pulmonary nodules that are not metastases [121]. In another study, approximately one-fourth of the indeterminate lesions on preoperative CT ultimately developed into metastases and 1 in 10 into other lung malignancies [122]. Chest CT examinations performed to evaluate for pulmonary metastases were typically performed with IV contrast material [121,123,124].


Staging of Colorectal Cancer

Staging of Colorectal Cancer. FDG-PET/CT Skull Base to Mid-Thigh Although there is some evidence to support the use of PET/CT in the local staging of patients with rectal carcinoma, the more common clinical application of PET/CT is in identifying nodal and distant metastases [125-127]. PET/CT is useful for determining overall stage and identifying patients with metastatic disease (sensitivity of 89% and specificity of 64%); however, the accuracy on a lesion-by-lesion basis is relatively low compared with contrast- enhanced CT and MRI for liver metastases (55% versus 89% in a study comparing PET/CT to MDCT) [128,129]. PET/CT may help to exclude other sites of disease beyond the liver or, in complex cases, to improve staging accuracy in which it has been shown to result in a change in management in up to 8% to 11% of patients [128,130- 132]. Caution should be exercised, however, as the findings of PET/CT may be nonspecific and could result in a negative impact on patient care in up to 9% of patients [128]. Additionally, PET/CT has further reduced sensitivity


Staging of Colorectal Cancer

Staging of Colorectal Cancer

Staging of Colorectal Cancer. Staging of Colorectal Cancer


Staging of Colorectal Cancer

Staging of Colorectal Cancer. for lesions in the setting of neoadjuvant therapy and should be used in conjunction with IV contrast CT or MRI for presurgical planning of liver metastases [133]. PET/CT may add influence in the positive predictive value of avid lymph nodes because it has a higher specificity than other modalities. The sensitivity of detecting nodal metastases is only 43% with a specificity of 80%, and again size is not a helpful characteristic.


Staging of Colorectal Cancer

Staging of Colorectal Cancer. Because of limited sensitivity of MRI for lung nodules, a chest CT can be utilized in addition to abdominal MRI for complete staging. The National Comprehensive Cancer Network recommends that patients with newly diagnosed colorectal cancer undergo staging chest CT, because staging chest CT has been shown to detect more lung metastases than chest radiography [119]. In a series of 74 patients with newly diagnosed rectal cancer who underwent both chest CT and chest radiography, 37% of patients with a normal chest radiograph had a lesion visible only on the chest CT, and 17% of these patients were found to have at least one pulmonary metastasis [119]. Among patients with potentially resectable liver metastases and a negative initial chest PET, additional imaging with a chest CT revealed pulmonary metastases in 5% of patients [120]. A potential pitfall of chest CT is the detection of small indeterminate pulmonary nodules that are not metastases [121]. In another study, approximately one-fourth of the indeterminate lesions on preoperative CT ultimately developed into metastases and 1 in 10 into other lung malignancies [122]. Chest CT examinations performed to evaluate for pulmonary metastases were typically performed with IV contrast material [121,123,124].


Staging of Colorectal Cancer

Staging of Colorectal Cancer. Staging of Colorectal Cancer Supporting Documents The evidence table, literature search, and appendix for this topic are available at https://acsearch.acr.org/list. The appendix includes the strength of evidence assessment and the final rating round tabulations for each recommendation.


Staging of Colorectal Cancer

Staging of Colorectal Cancer. For additional information on the Appropriateness Criteria methodology and other supporting documents go to www.acr.org/ac.


Suspected Pulmonary Hypertension

Suspected Pulmonary Hypertension. Diagnosis of PH remains challenging because of the diverse group of diseases that can cause PH as well as its nonspecific symptoms. Signs and symptoms of PH include dyspnea, fatigue, palpitations, angina, peripheral edema, hepatomegaly, ascites, syncope, and, rarely, unilateral vocal cord paralysis [4,10]. A careful history evaluation is critical to evaluate for risk factors for PH, including family history, history of drugs and toxins associated with PH, collagen vascular disease, human immunodeficiency virus (HIV), portal hypertension, congenital or left heart disease, and venous thromboembolic disease. Clinical evaluation includes pulmonary function tests, arterial blood gases, routine biochemistry, hematology, thyroid function, and serological testing to evaluate for lung disease, liver disease, connective tissue disorders, and HIV, as well as cardiothoracic imaging [10,11].


Suspected Pulmonary Hypertension

Suspected Pulmonary Hypertension. 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.


Suspected Pulmonary Hypertension

Suspected Pulmonary Hypertension. Reprint requests to: publications@acr.org


Suspected Pulmonary Hypertension

Suspected Pulmonary Hypertension

Suspected Pulmonary Hypertension. Suspected Pulmonary Hypertension


Suspected Pulmonary Hypertension

Suspected Pulmonary Hypertension. 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.


Suspected Pulmonary Hypertension

Suspected Pulmonary Hypertension. OR Discussion of Procedures by Variant Variant 1: Suspected pulmonary hypertension. Initial imaging. Radiography Chest PH tends to present with nonspecific symptoms; thus, chest radiography is often the first imaging test performed [11]. Multiple historic studies have shown that chest radiography is a useful study in the initial evaluation of PH [13-19]. Miniati et al [20] found that chest radiography has a high sensitivity (96.9%) and specificity (99.1%) for detection of moderate to severe PH. Additionally, chest radiography can show findings of diffuse lung diseases that can be associated with PH, such as interstitial fibrosis and emphysema [10,13]. Although chest radiography does well in detecting the presence/absence of PH in moderate and severe cases of PH, it performs poorly in estimating the PH severity [14]. Additionally, it is known to be insensitive in the detection of mild PH. Thus, a normal chest radiograph does not exclude PH, and further imaging evaluation should be pursued if there are persistent unexplained symptoms such as dyspnea or risk factors for PH [13,15,17,20,21].


Suspected Pulmonary Hypertension

Suspected Pulmonary Hypertension. Findings of PH on chest radiography include enlargement of the central pulmonary arteries, with or without rapid tapering (pruning), and right heart chamber enlargement [10,17,19,21]. A study by Schmidt et al [17] found that the main PA (MPA) was enlarged (>35 mm from midline to left lateral border of the PA on posterior anterior radiograph) 96% of the time in PH. A measurement of the right descending PA >15 mm in women (>16 mm in men) at the hilum on a posterior anterior view has good sensitivity, specificity, and accuracy for PH (93%, 88%, and 92%, respectively) and is considered to be a very useful finding [16-18]. A diameter of the left descending PA >18 mm on the lateral view is also suggestive of PH, but although it has good sensitivity (93%), the specificity (67%) and accuracy (87%) are poorer [16]. Other studies, such as that of Schmidt et al [17], have found poorer sensitivity for the left descending PA measurement. Miniati et al [20] found the most prevalent radiographic findings in patients with PH were enlarged MPA (97%), enlarged right ventricle (95%), and enlarged right descending PA (93%).


Suspected Pulmonary Hypertension

Suspected Pulmonary Hypertension. US Echocardiography Transthoracic Resting Transthoracic Doppler echocardiography is a noninvasive test that is a useful part of the initial evaluation of suspected PH [22]. A recent meta-analysis by Ni et al [23] showed that, overall, it has good sensitivity and fair specificity (85% and 74%, respectively) for detecting moderate to severe PH. However, it does not perform as well in detecting mild PH, particularly cases of PH secondary to lung diseases. Transthoracic Doppler echocardiography uses continuous wave Doppler to measure the peak tricuspid regurgitation velocity, which is used in combination with various echocardiographic signs suggestive of PH to assign a low, intermediate, or high echocardiographic probability of PH [24-26].


Suspected Pulmonary Hypertension

Suspected Pulmonary Hypertension. Echocardiographic signs suggestive of PH fall into 3 categories: right ventricular (RV) findings, PA findings, and inferior vena cava (IVC)/right atrial (RA) findings. RV findings include RV/left ventricular (LV) basal diameter ratio >1 and flattening of the interventricular septum. PA findings include PA diameter >25 mm, early diastolic


Suspected Pulmonary Hypertension

Suspected Pulmonary Hypertension. Transthoracic Doppler echocardiography is also useful in the assessment of multiple right heart parameters that are influenced by PH, including RA and RV size, RV systolic function, RV strain, tricuspid annular plane systolic excursion, and biventricular index. A biventricular index (RV end-diastolic area to LV end-diastolic area) >0.93 is associated with an increased risk of death in patients with PH [22,27]. The presence of pericardial effusion as well as valvular morphology and function are also easily assessed by echocardiography. An echocardiographic bubble study using agitated saline can be performed during the examination to assess for intracardiac shunts [11]. Studies have shown that real-time 3-D echocardiography evaluates RV volumes and the ejection fraction more accurately than conventional 2-D echocardiography [28]. In addition, pressure gradient-volume diagrams derived from 3-D echocardiography data can be used to reliably estimate RV stroke work in patients with PH [29].


Suspected Pulmonary Hypertension

Suspected Pulmonary Hypertension. Populations including those with a known genetic mutation associated with PAH, first degree relative with PAH, scleroderma spectrum, congenital heart disease, and portal hypertension before liver transplant are at high risk of developing PAH and may benefit from screening with echocardiography [30]. Patients with a high echocardiographic probability for PH have poorer postsurgical outcomes; thus, PH echocardiographic probability can also be used to risk stratify patients with risk factors for PH before a procedure/surgery [27,31]. As mentioned above, transthoracic Doppler echocardiography will not reliably detect mild, asymptomatic PH. Further evaluation with additional noninvasive examinations including CT and MRI may be obtained if there is persistent, high clinical suspicion for PH. RHC is also useful for further evaluation [10,24].


Suspected Pulmonary Hypertension

Suspected Pulmonary Hypertension. V/Q Scan Lung There are no data to suggest ventilation-perfusion (V/Q) scintigraphy as an initial test in the workup of suspected PH. However, current guidelines recommend V/Q scintigraphy of the lungs in all patients with unexplained PH to assess for CTEPH [24]. Identification of CTEPH is important because it allows for potentially curative surgical therapy [33]. V/Q scintigraphy typically shows mismatched wedge-shaped, segmental defects in the setting of CTEPH that can normalize after surgical treatment [34].


Suspected Pulmonary Hypertension

Suspected Pulmonary Hypertension. The high sensitivity and specificity of V/Q scintigraphy is useful for CTEPH detection [34]. A recent study by Mehari et al [35] comparing V/Q scintigraphy and multidetector CT pulmonary angiography (CTPA) for CTEPH detection found that V/Q scintigraphy had excellent sensitivity (90%) and good specificity (75%), whereas CTPA suffered from poor sensitivity (37%), although it had excellent specificity (100%). This is comparable to a prior study by Tunariu et al [36], which found that V/Q scintigraphy was more sensitive than multidetector CTPA in detecting chronic thromboembolic pulmonary disease amenable to surgery, with V/Q scans demonstrating a sensitivity of 96% to 97% and a specificity of 90% to 95% compared with a sensitivity of 51% and specificity of 99% for multidetector CTPA. However, a study that compared V/Q scanning versus CTPA by He et al [37] showed both techniques had good sensitivity, specificity, and accuracy at a center with significant CTEPH experience (100% versus 92%, 94% versus 95%, and 97% versus 94%, respectively). Compared with planar V/Q scanning, V/Q single-photon emission CT improves sensitivity and specificity, resulting in an accuracy of 94% [38]. The slightly lower specificity of V/Q scintigraphy relative to multidetector CTPA is secondary in patients with idiopathic


Suspected Pulmonary Hypertension

Suspected Pulmonary Hypertension. Suspected Pulmonary Hypertension PAH (IPAH) in whom abnormal V/Q scans can also be demonstrated whom can also demonstrate abnormal V/Q scans [33,38].


Suspected Pulmonary Hypertension

Suspected Pulmonary Hypertension. Although V/Q scintigraphy has excellent sensitivity for CTEPH, its greatest power lies with its negative predictive value. A normal or low-probability scan essentially excludes the diagnosis of CTEPH, although the V/Q scan may be normal in other causes of PH [10,24,33].


Suspected Pulmonary Hypertension

Suspected Pulmonary Hypertension. CT Chest CT chest is another noninvasive technique that can assess for PH. CT chest can be performed with or without intravenous (IV) contrast but is ideally performed with IV contrast to adequately visualize the pulmonary vasculature. CT chest without IV contrast is not a first-line test for suspected PH but may be useful to help look for etiologies of PH in patients who already hold a diagnosis of PH. There are no data support obtaining a CT chest with and without IV contrast in the setting of suspected PH.


Suspected Pulmonary Hypertension

Suspected Pulmonary Hypertension. In addition to demonstrating findings suggestive of PH, chest CT can also characterize various pulmonary etiologies that cause PH, including IPAH, pulmonary capillary hemangiomatosis (PCH), pulmonary veno-occlusive disease (PVOD), and many diffuse lung diseases. IPAH is characterized by plexiform lesions, which are networks of capillary-like channels in the wall of a dilated muscular PA that appear as ground glass centrilobular nodules. IPAH findings on CT include dilated central pulmonary arteries, centrilobular ground glass nodules associated with enlarged tortuous centrilobular arterioles, and pericardial effusion [21,46]. PCH, a diffuse proliferation of capillaries in the pulmonary interstitium, and PVOD, a disease of pulmonary venous hypertension secondary to pulmonary vein intimal fibrosis and subsequent venous occlusion, are rare diseases whose diagnosis can be suggested by findings on CT. On CT, PCH will have enlarged pulmonary arteries, centrilobular ground glass nodules, and interlobular septal thickening. PVOD presents on CT with enlarged pulmonary arteries, lymphadenopathy, pleural effusion, and interlobular septal thickening in the setting of a normal size left atrium. Surgical biopsy is necessary to confirm the diagnosis of PCH and PVOD [46-48].


Suspected Pulmonary Hypertension

Suspected Pulmonary Hypertension


Suspected Pulmonary Hypertension

Suspected Pulmonary Hypertension. uncommon finding in PH, has also been reported at CTA [52,53]. As with chest CT, evaluation with RHC remains necessary to confirm PH suspected on CTPA before initiating therapy [24].


Suspected Pulmonary Hypertension

Suspected Pulmonary Hypertension. MRI Heart Function and Morphology MRI can also noninvasively assess the MPA and right ventricle for PH with good sensitivity and specificity (92% and 80%, respectively) and is useful for RV morphology and function assessment. RV functional abnormalities secondary to PH-related cardiac remodeling include RV hypokinesis, leftward bowing and/or paradoxical movement of the interventricular septum, RV dysfunction (increased end-diastolic volume, reduced ejection fraction, reduced cardiac index, reduced stroke volume), and pulmonary and tricuspid insufficiency [59-62]. RV mass and LV mass can also be accurately determined, which can then be used to calculate a ventricular mass index (RV mass/LV mass), with a ratio >0.6 being abnormal [61,63,64]. Cardiac MRI shows many of the morphologic changes of PH that are also depicted by chest CT and CTPA: PA enlargement, MPA to adjacent ascending aorta ratio > 1, RV enlargement and hypertrophy, straightening of the interventricular septum, and pericardial thickening and effusion [61,65,66]. Measured parameters of RV ejection fraction, RV end diastolic volume, and RV-PA coupling metrics measured on cardiac MR have been shown to be important prognostic indicators of PH [59,65].


Suspected Pulmonary Hypertension

Suspected Pulmonary Hypertension. Additional characteristic findings of PH on cardiac MRI include findings on late gadolinium enhancement, T1 mapping, and phase-contrast sequences. Enhancement of the RV insertion points on late gadolinium enhancement imaging is commonly present in individuals with PH and is compatible with fibrosis related to RV stress [60,62,63,67]. T1 mapping will also show abnormally prolonged values at the RV insertion points in PH [68,69]. Cardiac MRI phase-contrast imaging techniques can measure average blood flow velocity of the MPA, which correlates with mPAP. Patients with PH have sluggish PA flow as demonstrated by prolonged acceleration times on phase-contrast imaging. Severity of tricuspid regurgitation can be accurately quantified with 2-D phase-contrast imaging and used to estimate MPA pressure [65,70,71]. More recently, 4-D flow has been used to assess the MPA and detect the hemodynamic alterations that occur with PH: decreased wall shear stress, increased tricuspid regurgitation velocity, and abnormal vortex blood flow pattern within the MPA that is associated with early-onset systolic retrograde flow [65,72-74].


Suspected Pulmonary Hypertension

Suspected Pulmonary Hypertension. MRA Chest Pulmonary MR angiography (MRA) shows morphologic changes of PH that are also depicted by MRI heart and CT/CTPA: PA enlargement, MPA to adjacent ascending aorta ratio >1, RV enlargement and hypertrophy, straightening of the interventricular septum, and pericardial thickening and effusion [61,65,66]. MRA has lower sensitivity for the detection of acute and chronic pulmonary embolism compared with CTPA [61]. There are no data to support the use of MRA chest alone as a first-line test for suspected PH; however, the combination of MRA


Suspected Pulmonary Hypertension

Suspected Pulmonary Hypertension. Catheterization Right Heart RHC is an invasive procedure that defines cardiopulmonary hemodynamics and is performed after all noninvasive examinations have been completed to confirm the diagnosis of PH before initiating treatment per current guidelines [24]. RHC directly measures the PAP to confirm the diagnosis of PH as well as the PAWP and cardiac function (thermodilution or Fick method), which are both necessary to determine PVR. The mean PAP, PAWP, and PVR values obtained from RHC are used to classify PH into precapillary PH, isolated postcapillary pH, or combined pre- and postcapillary PH [78-80]. Vasoreactivity testing of the pulmonary circulation may also be performed at the time of RHC in selected patients with IPAH, heritable PAH, and drug-induced PAH to determine candidacy for calcium channel blocker treatment [79]. RHC has morbidity and mortality rates of 1.1% and 0.055%, respectively [81].


Suspected Pulmonary Hypertension

Suspected Pulmonary Hypertension. Supporting Documents The evidence table, literature search, and appendix for this topic are available at https://acsearch.acr.org/list. The appendix includes the strength of evidence assessment and the final rating round tabulations for each recommendation.


Suspected Pulmonary Hypertension

Suspected Pulmonary Hypertension. For additional information on the Appropriateness Criteria methodology and other supporting documents go to www.acr.org/ac.


Suspected Pulmonary Hypertension

Suspected Pulmonary Hypertension

Suspected Pulmonary Hypertension. Suspected Pulmonary Hypertension


Suspected Physical Abuse Child

Suspected Physical Abuse Child. Introduction/Background Based on reports to child and protective service agencies, an estimated 3.2 million children were investigated for maltreatment (neglect, emotional abuse, sexual abuse, and physical abuse) in the United States in 2013, and an estimated 679,000 (9.1/1000 children) were victims of abuse [1]. The youngest children are most vulnerable; children in their first year of life had the highest rate of victimization at 23.1/1000. An estimated 1520 children died from abuse, with three-fourths of these under 3 years of age. However, the full extent of child abuse is not known because of underreporting [2,3].


Suspected Physical Abuse Child

Suspected Physical Abuse Child. Overview of Imaging Modalities X-ray skeletal survey The radiographic skeletal survey is the primary imaging examination for detecting fractures [11]. The skeletal survey should be composed of frontal and lateral views of the skull, lateral views of the cervical spine and thoracolumbosacral spine, and single frontal views of the long bones, hands, feet, chest, and abdomen. Oblique views of the ribs should be obtained to increase the accuracy of diagnosing rib fractures [12,13], which are strong positive predictors and may be the only skeletal manifestation of abuse [14,15].


Suspected Physical Abuse Child

Suspected Physical Abuse Child. The images should be obtained using high-detail imaging systems and coned to the specific area of interest for each of the body parts, with separate views of each arm, forearm, thigh, leg, hand, and foot to improve image quality and diagnostic accuracy [16] (see Appendix 1). Fractures most often involve the long bones and ribs, with lesser involvement of the skull and clavicles and even less frequent involvement of the pelvis, spine, hands, and feet [17]. It has therefore been questioned whether the radiation exposure outweighs the potential benefit of imaging the pelvis, spine, hands, and feet on initial skeletal survey [17-20]. Although not part of American


Suspected Physical Abuse Child

Suspected Physical Abuse Child. Reprint requests to: publications@acr.org


Suspected Physical Abuse Child

Suspected Physical Abuse Child. College of Radiology (ACR) or American Academy of Pediatrics guidelines, some add lateral radiographs of the long bones, which have been shown to increase detection of metaphyseal fractures by 50% [21]. A repeat skeletal survey performed approximately 2 weeks after the initial examination can provide additional information on the presence and age of child abuse fractures [22] in up to 12% of children and should be performed when abnormal or equivocal findings are found on the initial study and when abuse is suspected on clinical grounds [23]. To limit radiation exposure, pelvis, spine, and skull radiographs can be omitted if no injury was initially seen in these regions [24-26]. However, it is not possible to exactly date fractures by radiography [27].


Suspected Physical Abuse Child

Suspected Physical Abuse Child. Tc-99m bone scan whole body In experienced hands, bone scintigraphy is a complementary/adjunctive examination for detecting bone injuries [28,29] but is usually not considered an alternative to skeletal survey. It should be used when the radiographic skeletal survey is negative but clinical suspicion remains high and a search for further evidence of skeletal trauma is warranted. It may aid by detecting bony injury that is occult, equivocal, or subtle on plain radiographs, but it requires venipuncture and often requires sedation. In addition to standard images, the use of pinhole collimators [29] and differential counts of the metaphyses may improve sensitivity. A bone scan is especially good for detecting periosteal reaction and rib, spine, pelvic, and acromion fractures [23,30]. However, skull fractures and fractures near the growth plates, because of normally increased activity in the growth plate, may be difficult to appreciate [31,32]. Bone scan is also not useful in dating of fractures, as the scan may be active for up to a year after injury [29].


Suspected Physical Abuse Child

Suspected Physical Abuse Child. CT head without contrast Unenhanced computed tomography (CT) of the head is the examination of choice to evaluate children with suspected abusive head trauma (AHT) [33]. These include children who had skeletal survey for suspected child abuse, children with neurological changes, and children with facial injuries raising concern for abuse. Multiplanar reformations and 3-D volume rendering of the skull increase sensitivity for fracture and intracranial hemorrhage [34,35].


Suspected Physical Abuse Child

Suspected Physical Abuse Child. MRI head without contrast Magnetic resonance imaging (MRI) is sensitive for the detection of small-volume extra-axial hemorrhage and for evolving parenchymal injury [36]. In addition to standard sequences, diffusion-weighted imaging and susceptibility-weighted imaging increase sensitivity for detection of parenchymal ischemia, diffuse axonal injury, and microhemorrhage and can provide prognostic information in AHT. The addition of contrast-enhanced MRI sequences can be used in select cases to improve evaluation of extra-axial collections [37] as it increases the sensitivity for the detection of membranes in subdural collections, a finding that indicates a chronic component [37]. Care must be taken when attempting to date subdural collections, however, as the imaging appearance depends not just on the age of blood products but also on the potential presence of cerebrospinal fluid accumulation in the subdural space through an arachnoid laceration (hematohygroma) [38]. Thrombosis of bridging veins in the subdural space also suggest abusive trauma [39,40].


Suspected Physical Abuse Child

Suspected Physical Abuse Child. The MRI should include T1- and T2-weighted imaging as well as T2 FLAIR and T2* (gradient-echo or susceptibility-weighted imaging) sequences. Diffusion-weighted sequences are required to indicate whether acute cerebral injury is present [36]. Susceptibility-weighted imaging may be useful in detection of blood products in the brain as well as retinal hemorrhages [41,42]. MRI is a particularly good choice to image children at high risk for AHT in the nonemergent setting but is a lengthy scan often requiring sedation, so it is typically not utilized in the emergent setting.


Suspected Physical Abuse Child

Suspected Physical Abuse Child. MRI spine Recent evidence supports that spine injury is common in children with AHT. In recent retrospective studies [43- 45], ligamentous injury at the craniocervical junction and spinal subdural hemorrhage (SDH) are reported in 36% to 78% and 44% to 63% of AHT cases, respectively. MRI of the cervical spine, including fat-suppressed fluid- sensitive sequences, a sagittal short tau inversion recovery or T2 fat-saturated sequence, should be performed in all cases where the skeletal survey demonstrates any fractures or when clinical concern for craniocervical junction or spinal injury is high. The prevalence of spine fracture is increased to almost 10% in the setting of a positive skeletal survey and is significantly associated with intracranial injury [18]. The high incidence of cervical injuries in abused children with bilateral hypoxic-ischemic brain injuries suggests a causal relationship [44].


Suspected Physical Abuse Child

Suspected Physical Abuse Child. The value of routine screening of the whole spine in suspected AHT is still debated. In a subgroup of 38 children with AHT who underwent thoracolumbar spine imaging, 24 (63%) had thoracolumbar SDH, whereas only 1 of 70


Suspected Physical Abuse Child

Suspected Physical Abuse Child. patients with accidental trauma had spinal SDH in the same study [43]. None of the children had spinal cord compression or long-term complications from the presence of the spinal SDH, and that imaging was performed mostly because of concern for thoracic or abdominal injury. Although not usually prompting change in management, detection of spinal SDH is significantly increased when imaging is extended through the thoracolumbar spine [45]. The presence of thoracolumbar SDH does not imply direct trauma to the thoracolumbar spine and may be related to redistribution of blood products. Nevertheless, this finding has medicolegal implications as it may document otherwise undetected injury and may help distinguish between abusive and accidental injury.


Suspected Physical Abuse Child

Suspected Physical Abuse Child. CT chest without contrast CT of the chest is more sensitive than chest radiography in detection of rib fractures; chest radiography defines only about 60% of the fractures that are detected by CT [46]. Anterior and posterior fractures are better seen by CT, as are bilateral fractures. However, the need for sedation in noncooperative children makes this test a useful adjunct rather than a first-line test in the imaging workup of nonaccidental trauma (NAT). A reduced-dose chest CT may detect rib fractures in infants with high suspicion for NAT and a normal initial 4-view chest, with a sub- millisievert radiation dose equaling twice that of a 4-view chest [47]. Multiplanar reformatted images may aid in rib fracture detection [48]. In addition, chest CT may detect scapular and spine fractures not evident on skeletal survey [47].


Suspected Physical Abuse Child

Suspected Physical Abuse Child. CT chest with contrast A CT scan of the chest with intravenous (IV) contrast is reserved for children with clinical suspicion of intrathoracic traumatic injury. IV contrast allows for detection of vascular injuries.


Suspected Physical Abuse Child

Suspected Physical Abuse Child. CT abdomen and pelvis with contrast CT of the abdomen and pelvis with IV contrast is utilized for children with suspected intra-abdominal and/or intrapelvic injury [49]. Portal venous phase imaging is most helpful for detecting solid-organ injury. Delayed excretory-phase imaging may be useful in a few selected cases when imaging findings suggest disruption of the genitourinary tract. Noncontrast abdominal CT is not recommended. The need for oral contrast is at the discretion of the radiologist, and its use may be considered when there is concern for duodenal hematoma [23].


Suspected Physical Abuse Child

Suspected Physical Abuse Child. Tc-99m bone scan whole body Bone scintigraphy is a complementary/adjunctive examination for detecting bone injuries [28,29] but is usually not considered an alternative to skeletal survey. It should be used when the radiographic skeletal survey is


Suspected Physical Abuse Child

Suspected Physical Abuse Child. negative but clinical suspicion remains high and search for further evidence of skeletal trauma is warranted. It may aid by detecting bony injury that is occult, equivocal, or subtle on plain radiographs, but it requires venipuncture and often requires sedation.


Suspected Physical Abuse Child

Suspected Physical Abuse Child. CT head and MRI head There are varying opinions on how to image suspected abuse victims who show no evidence suggesting intracranial injury. Although skull radiographs may detect fractures associated with intracranial pathology, they do not provide adequate screening, since significant traumatic intracranial pathology may occur in the absence of skull fractures [58,59]. Children, especially those <12 months of age, may have significant intracranial injury without signs or symptoms of head injury or retinal hemorrhage [60-62]. Unenhanced CT of the head is the examination of choice for initial evaluation for intracranial injury in child abuse [33]. MRI is a good choice to image children for abusive head injury in the nonemergent setting.


Suspected Physical Abuse Child

Suspected Physical Abuse Child. A study of abused children without clinical suspicion of intracranial injury showed that 11 (29%) of the 51 children had positive neuroimaging including subdural hematoma, epidural hematoma, or cerebral edema; most of them had negative skeletal surveys and no retinal hemorrhage. Eight of the 11 children were <12 months of age [60]. In another prospective study of infants <6 months of age evaluated for possible physical abuse, the presence of apparently isolated bruises (seen in 146 children) at presentation correlated with new injury on neuroimaging in 40 children (27%) [50]. In yet another study [61], 37% of children <2 years of age with high-risk criteria (defined as rib fractures, multiple fractures, facial injury, or <6 months of age) and without overt signs of head injury who underwent head CT or MRI had occult head injury; nearly all with occult head injury were <1 year of age. Intracranial injury is also associated with spinal trauma seen on skeletal survey [18]. Given these studies, clinicians should have a relatively low threshold for performing either CT (emergent setting and more sensitive for detection of nondisplaced fractures) or MRI of the head in children with suspected abuse.


Suspected Physical Abuse Child

Suspected Physical Abuse Child. In summary, there is no strong evidence to recommend universal screening with neuroimaging. However, clinicians should have low threshold for performing head CT or MRI in young children with suspected child abuse.


Suspected Physical Abuse Child

Suspected Physical Abuse Child. Variant 2: Suspected physical abuse. Child >24 months of age. Neurological or visceral injuries not clinically suspected. Initial imaging evaluation. X-ray area of interest Children >2 years of age are often able to verbalize the area(s) of injury or pain during clinical examination. Thus, initial imaging should focus on the areas of clinical concern.


Suspected Physical Abuse Child

Suspected Physical Abuse Child. Tc-99m bone scan whole body Bone scintigraphy is a complementary/adjunctive examination for detecting bone injuries. It may aid by detecting bony injury that is occult, equivocal, or subtle on plain radiographs, but the study requires venipuncture and often requires sedation.


Suspected Physical Abuse Child

Suspected Physical Abuse Child. CT head and MRI head Unenhanced CT of the head is the examination of choice for acute evaluation for intracranial injury in child abuse [33]. However, there is no strong evidence to recommend universal screening with neuroimaging in the absence of clinical suspicion for AHT. This is particularly true in older children where the neurological examination is typically more reliable, except for children with chronic disabilities.


Suspected Physical Abuse Child

Suspected Physical Abuse Child. MRI is a good choice to image children for abusive head injury in the nonemergent setting. MRI is useful in the detection of small-volume extra-axial hemorrhage and for evolving parenchymal injury [36]. Diffusion-weighted imaging and susceptibility-weighted imaging increase the sensitivity for detection of parenchymal ischemia, diffuse axonal injury, and microhemorrhage. The addition of contrast-enhanced MRI sequences can be utilized in select cases to improve evaluation of extra-axial fluid collections.


Suspected Physical Abuse Child

Suspected Physical Abuse Child. Variant 3: Child with one or more of the following: neurologic signs or symptoms, apnea, complex skull fracture, other fractures, or injuries highly suspicious for child abuse. Initial imaging evaluation. X-ray skeletal survey The skeletal survey is the primary examination for detecting fractures [11]. Fractures occur in up to 55% of physically abused children [29]; 80% of abused children with fractures are <18 months of age [4]. Thus, skeletal survey is recommended in all children <2 years of age in whom there is suspicion of abuse [51,52].


Suspected Physical Abuse Child

Suspected Physical Abuse Child. Tc-99m bone scan whole body Bone scintigraphy is a complementary/adjunctive examination for detecting bone injuries. It may aid by detecting bony injury that is occult, equivocal, or subtle on plain radiographs. Skull fractures and fractures near the growth plates, however, may be difficult to appreciate [31,32].


Suspected Physical Abuse Child

Suspected Physical Abuse Child. In children with skull fractures or clinical signs and symptoms of intracranial injury, an immediate noncontrast CT scan of the head should be performed. Contrast administration for the head CT examination is not indicated. If the CT scan does not detect significant lesions that require rapid neurosurgical intervention and the clinical presentation warrants further assessment, a MRI scan of the head should be performed.


Suspected Physical Abuse Child

Suspected Physical Abuse Child. MRI head Additional diagnostic information will be found on MRI over CT in about 25% of patients [36], and MRI can also contribute to prognosis. In a child with an abnormal CT, additional assessment with MRI should be considered to further assess the extent of post-traumatic injury. Care should be taken in trying to determine the age of subdural hematomas by CT or MRI [67,68]. Although hyperdense blood products can be considered acute, collections of low or intermediate density do not indicate necessarily chronic blood products, as lacerations of the arachnoid may result in subdural hygromas or hematohygromas in the early or late post-traumatic periods. MR venography utilizing unenhanced 2-dimensional time-of-flight technique can be used to assess patency of the dural venous sinuses and deep venous system.


Suspected Physical Abuse Child

Suspected Physical Abuse Child. Neuroimaging should not be performed as a screening examination in all children but should be used for further evaluation of all abnormal initial examinations and in cases of clinical suspicion [36]. The clinician should have a relatively low threshold for performing either CT (emergent setting) or MRI of the head (nonemergent setting), especially in children under 1 year of age [60,61].


Suspected Physical Abuse Child

Suspected Physical Abuse Child. MRI cervical spine MRI of the cervical spine should be strongly considered at the time of MRI brain imaging, as unsuspected spinal injuries may be demonstrated in >36% of cases [44]. Cervical spine injury, particularly at the craniocervical junction, is highly associated with bilateral hypoxic-ischemic injury. Most cervical spine injury detected by MRI in abused infants is ligamentous.


Suspected Physical Abuse Child

Suspected Physical Abuse Child. MRI complete spine MRI of the entire spine may show thoracolumbar SDH, most commonly from redistribution of blood products; however, it rarely results in cord compression or alters clinical management. An MRI of the total spine should be reserved for cases where the distinction between abusive and accidental trauma is not clear, since thoracolumbar SDH is more commonly seen with abusive trauma [43].


Suspected Physical Abuse Child

Suspected Physical Abuse Child. Variant 4: Child. Suspected physical abuse. Suspected thoracic or abdominopelvic injuries (eg, abdominal skin bruises, distension, tenderness, or elevated liver or pancreatic enzymes). Initial imaging evaluation. X-ray skeletal survey As most children with thoracic or abdominopelvic injury from child abuse have polytrauma [69], skeletal survey is recommended in all children 24 months of age or younger and should be considered in older children.


Suspected Physical Abuse Child

Suspected Physical Abuse Child. Tc-99m bone scan whole body Bone scintigraphy is a complementary/adjunctive examination for detecting bone injuries. It may aid by detecting bony injury that is occult, equivocal, or subtle on plain radiographs.


Suspected Physical Abuse Child

Suspected Physical Abuse Child. CT head and MRI head CT or MRI of the head should also be performed in children with neurologic symptoms or risk factors for intracranial injuries (see variant 3).


Suspected Physical Abuse Child

Suspected Physical Abuse Child. CT of the abdomen and pelvis Nonskeletal injuries to the chest, abdomen, and pelvis can occur as the result of child abuse. Child abuse should be considered in any child with thoracoabdominal injuries that are not consistent with the provided history.


Suspected Physical Abuse Child

Suspected Physical Abuse Child. Up to 10% of abused children have intra-abdominal injury [49]; 15% of children aged 0 to 4 years hospitalized for abdominal injury are victims of child abuse [70,71]. Victims of nonaccidental abdominal trauma tend to be younger and have a more delayed presentation than those who experience accidental trauma [72]. Clinical findings of abdominal pain, abdominal distension, vomiting, abdominal wall bruising, and hypoactive or absent bowel sounds may suggest intra-abdominal injury [73-75]. Abnormal liver transaminases and pancreatic enzymes may be seen with occult abdominal trauma [74,75].


Suspected Physical Abuse Child

Suspected Physical Abuse Child. One series suggested that nearly half of abused children with abdominal injury require surgical intervention [76]. In addition, independent of concomitant injury, blunt trauma due to child abuse is associated with a 6-fold increase in odds of death compared to children whose injuries resulted from accidental trauma [70]. Nonskeletal abdominopelvic injuries include pancreatitis, pancreatic pseudocysts, and lacerations and contusions of the liver, adrenal gland, spleen, kidneys, and bowel (especially duodenum) [77,78]. Bowel injuries and pancreatic injuries are seen disproportionately more often in child abuse compared to accidental trauma [49]. Contrast-enhanced CT of the abdomen is indicated in acute evaluation of the child with suspected abdominopelvic injuries. The use of ultrasound in the acute setting is limited, as both focused abdominal scan in trauma and standard abdominopelvic ultrasound are less sensitive than CT in detection of hemoperitoneum and solid-organ injuries [79,80]. Noncontrast CT of the abdomen is not adequately sensitive in detection of intrathoracic or intra-abdominal trauma. Routine CT scan screening for abdominal or chest injury is not recommended [72].


Suspected Physical Abuse Child

Suspected Physical Abuse Child. CT of the chest Injuries to the chest (other than the ribs) are uncommon and include hemopericardium, cardiac contusions and lacerations, pleural effusion, and lung contusions [23,64,77,81]. Contrast-enhanced CT of the chest is indicated in acute evaluation of the child with these types of suspected nonskeletal intrathoracic injury; noncontrast CT of the chest is not adequately sensitive. Routine CT scan screening for chest injury is not recommended [72].


Suspected Physical Abuse Child

Suspected Physical Abuse Child. In children <24 months of age, a repeat skeletal survey performed approximately 2 weeks after the initial examination can detect fractures not seen on initial skeletal survey, can clarify equivocal findings, and can provide information on the age of child abuse fractures [22,26,83]. Nine to 12% of infants have healing fractures on follow-up survey after a negative initial survey [82,84], and up to one-third of follow-up surveys yield new information [84]. Half to three-fourths of these newly detected fractures are rib fractures [26,82,84]; classic metaphyseal lesions are the second most common [83]. As such, many authors have suggested a more limited follow-up skeletal survey, as described above. However, it is not possible to exactly date fractures by radiography [27].


Suspected Physical Abuse Child

Suspected Physical Abuse Child. Tc-99m bone scan whole body In selected cases, when it is not possible to wait 2 weeks for a follow-up skeletal survey radiograph, a bone scan can be considered. Bone scan is sensitive in detecting radiographically occult fractures. It is particularly useful in detection of fractures of the ribs, scapula, spine, and pelvis [30]. It is not sensitive, however, in the detection of skull fractures [29]. Metaphyseal injury may be difficult to see because of the adjacent normal metabolically


Suspected Physical Abuse Child

Suspected Physical Abuse Child. active physis. Radiation exposure is higher than a skeletal survey [29]. If used in follow-up, radiographs of areas of abnormal uptake should also be performed.


Suspected Physical Abuse Child

Suspected Physical Abuse Child. CT chest Low-dose noncontrast CT of the chest also offers a time advantage over repeat skeletal survey. It is useful in the detection of rib, scapula, and thoracic spine fractures not seen on skeletal survey [47]. Anterior and posterior rib fractures are detected more often by CT than by skeletal survey [46]. Fractures may also be dated as acute, subacute, or chronic [46,85]. It would not replace contrast-enhanced chest CT in initial evaluation of nonskeletal thoracic injuries, such as hemopericardium, cardiac contusions and lacerations, pleural effusion, and lung contusions [23,64,77,81].


Suspected Physical Abuse Child

Suspected Physical Abuse Child. CT head and MRI head Follow-up neuroimaging is usually not indicated in the setting of a negative skeletal survey and absence of clinical suspicion of AHT. If there is suspicion for injury after the initial evaluation, neuroimaging should be considered. Noncontrast CT is useful in the evaluation of healing skull fractures, whereas MRI is the method of choice to evaluate the intracranial compartment.


Suspected Physical Abuse Child

Suspected Physical Abuse Child. Summary of Recommendations The appropriate imaging of pediatric patients being evaluated for suspected physical abuse depends upon the age of the child, the presence of neurological signs and symptoms, and evidence of visceral thoracic or abdominopelvic injuries. A skeletal survey is indicated in the initial imaging evaluation of a child 24 months of age or younger. In older children, it is usually appropriate to target imaging to the area(s) of suspected injury. Skeletal survey and CT head without contrast are indicated in the emergent/initial imaging evaluation of a child with neurologic signs and symptoms, complex skull fracture, apnea, multiple fractures, spine trauma, or facial injury. These examinations are not indicated for general screening.


Suspected Physical Abuse Child

Suspected Physical Abuse Child. MRI head may provide additional diagnostic information to head CT in about 25% of children. MRI of the cervical spine should be considered at the time of head MRI, as unsuspected injury (usually ligamentous) may be present in over 33% of children with intracranial injury.


Suspected Physical Abuse Child

Suspected Physical Abuse Child. Skeletal survey and CT chest/abdomen/pelvis with IV contrast are indicated if there are signs or symptoms of intrathoracic or intra-abdominal visceral injury (abdominal pain/distension/bruising, abnormal liver, or pancreatic enzymes, etc). In children 24 months of age or younger with equivocal skeletal survey or with a high clinical suspicion for abuse and a negative initial skeletal survey, a repeat limited/focused skeletal survey performed at 2 weeks may add diagnostic information.


Suspected Physical Abuse Child

Suspected Physical Abuse Child. Although there are references that report on studies with design limitations, 2 good-quality studies provide good evidence.


Suspected Physical Abuse Child

Suspected Physical Abuse Child. Relative Radiation Level Information Potential adverse health effects associated with radiation exposure are an important factor to consider when selecting the appropriate imaging procedure. Because there is a wide range of radiation exposures associated with different diagnostic procedures, a relative radiation level (RRL) indication has been included for each imaging examination. The RRLs are based on effective dose, which is a radiation dose quantity that is used to estimate population total radiation risk associated with an imaging procedure. Patients in the pediatric age group are at inherently higher risk from exposure, both because of organ sensitivity and longer life expectancy (relevant to the long latency that appears to accompany radiation exposure). For these reasons, the RRL dose estimate ranges for


Suspected Physical Abuse Child

Suspected Physical Abuse Child. Supporting Documents For additional information on the Appropriateness Criteria methodology and other supporting documents go to www.acr.org/ac.


Tinnitus

Tinnitus. Introduction/Background Tinnitus is a symptom defined by the perception of sound in the absence of external stimuli. It affects more than 50 million Americans, equally among men and women, and is most commonly noted in patients between 40 and 70 years of age [1]. Tinnitus may range from innocuous to devastating, with significant negative impacts on psychosocial well-being and quality of life. In a survey conducted in 2008, approximately 10% of the United States adult population experienced endorsed at least 1 episode of tinnitus lasting more than 5 minutes in the preceding year [2].


Tinnitus

Tinnitus. It is important to know the otoscopy examination findings in patients with PT because it guides the imaging algorithm. In the setting of PT, the possibility of a vascular retrotympanic lesion leads to a different set of differential diagnostic considerations compared to the absence thereof and therefore influences the decision for which imaging studies to pursue and in what order. However, the detection of retrotympanic lesions can be difficult without appropriate equipment.


Tinnitus

Tinnitus. The American Academy of Otolaryngology and Head and Neck Surgery Foundation (AAO-HNS) guidelines recommend targeted history and clinical examination as the initial evaluation and determination as to whether the tinnitus is bothersome or not, before any imaging. The guidelines also recommend a prompt and comprehensive audiological examination in patients with hearing problems or with unilateral persistent tinnitus. The guidelines make a strong recommendation against any imaging studies of the head and neck for the subset of patients in whom tinnitus does not localize to 1 ear, is nonpulsatile, and is not associated with focal neurological abnormalities or an asymmetric hearing loss. The guidelines also suggest that some patients with severe anxiety, depression, or psychological disturbances may need prompt identification and intervention [6,7].


Tinnitus

Tinnitus. aMetroHealth Medical Center, Cleveland, Ohio. bPanel Chair, University of Iowa Hospitals and Clinics, Iowa City, Iowa. cPanel Vice-Chair, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Massachusetts. dThe Ohio State University Wexner Medical Center, Columbus, Ohio; American Academy of Otolaryngology-Head and Neck Surgery. eFroedtert Memorial Lutheran Hospital Medical College of Wisconsin, Milwaukee, Wisconsin. fHouston Methodist Hospital, Houston, Texas. gHouston Methodist Hospital, Houston, Texas. hThe University of Texas MD Anderson Cancer Center, Houston, Texas. iNew York University Langone Medical Center, New York, New York. jMayo Clinic, Rochester, Minnesota; Commission on Nuclear Medicine and Molecular Imaging. kSentara Norfolk General Hospital/Eastern Virginia Medical School, Norfolk, Virginia; American College of Emergency Physicians. lJohns Hopkins University School of Medicine, Baltimore, Maryland; American Geriatrics Society. mMayo Clinic Arizona, Phoenix, Arizona. nColumbia University Medical Center, New York, New York; American Academy of Neurology. oEvansville Primary Care, Evansville, Indiana; American Academy of Family Physicians. pGeorge Washington University Hospital, Washington, District of Columbia. qUniversity of Colorado Denver, Denver, Colorado. rSpecialty Chair, Montefiore Medical Center, Bronx, New York.


Tinnitus

Tinnitus. 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.


Tinnitus

Tinnitus. Reprint requests to: publications@acr.org


Tinnitus

Tinnitus. Special Imaging Considerations CT angiography (CTA) can be performed to include a mixed arterial and venous phase through the head and neck in selected clinical scenarios. In these cases, imaging can be performed after peak arterial timing and can be obtained approximately 20 to 25 seconds after injection of intravenous (IV) contrast material. This allows for a single test with lower total radiation dose when compared to separate CTA and CT venography (CTV) examinations. Overlapping of vessels is not problematic, and it shows not only both arterial and venous anatomy and pathology adequately in this balanced phase but also the bony details of the temporal bone when reconstructed in thin bone window settings [1,11,12].


Tinnitus

Tinnitus. MR brain, when performed for temporal bone/skull base evaluation of tinnitus, is usually performed using specialized internal auditory canal (IAC) protocols, which include thin-section, heavily T2-weighted sequences to evaluate for vascular loops and small vestibular schwannomas. Volumetric postcontrast T1-weighted images are also increasingly becoming a part of this protocol, which has the added benefit of assessment of the transverse and sigmoid sinuses. Functional MRI in patients with tinnitus is still a research tool and is not used in routine applications [13,14]. Venous arterial spin-labeling technique has a high sensitivity and specificity for the presence of a dural arteriovenous fistula (dAVF), and the addition of spin-labeling increases confidence in the diagnosis of this entity on MRI [15].


Tinnitus

Tinnitus. Time-resolved gadolinium-enhanced MR angiography (MRA) is a technique which combines many factors like T1 shortening effect of gadolinium, digital subtraction technique, dynamic imaging, and parallel imaging to provide high temporal resolution MRA images. Use of intelligent k-space sampling technique can further improve the spatial and temporal resolution. The rapid acquisition of multiple 3-D volumes with high temporal and spatial resolution renders excellent depiction of the vessels to detect dAVFs [16-18].


Tinnitus

Tinnitus. OR Discussion of Procedures by Variant Variant 1: Pulsatile tinnitus, unilateral or bilateral; no retrotympanic lesion on otoscopy. Initial imaging. PT has many causes, and no single imaging study is appropriate for all patients. A diagnostic algorithm based on a detailed history and clinical evaluation should progress from less invasive to more invasive imaging studies. The history and clinical assessment have implications on the choice of imaging modality [12,19]. For example, an otoscopic examination is extremely useful to help guide optimal imaging evaluation of PT.


Tinnitus

Tinnitus. Tinnitus Sigmoid sinus wall dehiscence and sigmoid sinus diverticulum are collectively called sigmoid sinus wall abnormalities (SSWA) and are increasingly recognized causes of PT [19,25-27].


Tinnitus

Tinnitus. Structural and anatomic causes of PT can be found in up to 44% to 91% of patients; however, in some studies, many patients remained idiopathic even after extensive workup [28,29].


Tinnitus

Tinnitus. The history and physical examination may also suggest PT due to systemic causes such as pregnancy-related hemodynamic changes, anemia, thyrotoxicosis, or due to mechanical causes like palatal or tympanic myoclonus, Eustachian tube contractions, or temporomandibular joint problems [30-34].


Tinnitus

Tinnitus. Arteriography Cervicocerebral Arteriography is an invasive test, which can diagnose many conditions causing PT, and is used when noninvasive tests like CTA and MRA are inconclusive and there is persistent clinical suspicion for a vascular lesion. It is particularly useful for detecting dAVFs and other lesions with arteriovenous shunts such as AVM and carotid cavernous sinus fistulas [35]. These lesions may cause PT, and arteriography has a higher sensitivity and specificity than MRA or CTA, which are used for screening. Therefore, arteriography is still useful if CTA/MRA is negative but dAVF remains suspected to be the cause of PT [23,29]. It is also useful for preoperative planning and embolization for paragangliomas [36]. A study found an incidence of 24% for arteriovenous shunts in patients who were referred for digital subtraction angiography (DSA) for evaluation of PT. Other retrospective studies showed a prevalence of 2% to 27% for arteriovenous shunts in patients with PT undergoing DSA [35]. Cervical artery dissection (carotid or vertebral) can also cause PT in 8% to 10% of patients with PT and can be diagnosed by CTA, MRA, or catheter arteriography. Catheter arteriography is rarely required for this indication; however, because of the excellent accuracy of CTA and MRA [37,38].


Tinnitus

Tinnitus. CT Head With IV Contrast There is no relevant literature to support the use of CT head with IV contrast for evaluation of PT when otoscopy does not show a vascular retrotympanic lesion.


Tinnitus

Tinnitus. CT Head Without and With IV Contrast There is no relevant literature to support the use of CT head without and with IV contrast for evaluation of PT when otoscopy does not show a vascular retrotympanic lesion.


Tinnitus

Tinnitus. CT Head Without IV Contrast There is no relevant literature to support the use of CT head without IV contrast for evaluation of PT when otoscopy does not show a vascular retrotympanic lesion.


Tinnitus

Tinnitus. CT Temporal Bone With IV Contrast There is no relevant literature to support the use of CT temporal bone with IV contrast for evaluation of PT when otoscopy does not show a vascular retrotympanic lesion. IV contrast is not needed in the assessment of semicircular canal dehiscence, enlarged vestibular aqueduct, SSWA, jugular bulb dehiscence, or glomus jugulare paraganglioma. This may detect transverse sinus stenosis and some cases of dAVFs but cannot assess the neck vessels.


Tinnitus

Tinnitus. CT Temporal Bone Without and With IV Contrast There is no relevant literature to support the use of CT temporal bone without and with IV contrast for evaluation of PT when otoscopy does not show a vascular retrotympanic lesion.


Tinnitus

Tinnitus. CT Temporal Bone Without IV Contrast CT temporal bone without IV contrast does not show the arterial abnormalities in the neck, or intracranial vascular abnormalities such as dAVF, AVM, and transverse sinus stenosis, which are potential causes in this setting. High- resolution CT (HRCT) of the temporal bone can detect some other conditions that cause PT but do not always present as a vascular retrotympanic mass, such as otospongiosis, Paget disease, sigmoid sinus diverticulum and sigmoid sinus dehiscence, high-riding jugular bulb, and SSCD [39]. SSCD is a known cause of PT and other symptoms of peripheral vestibulopathy and is readily diagnosed on CT temporal bone [40,41]. SSWAs are known causes of PT and may be the most common identifiable causes in this group [25]. They are much more frequently seen on CT temporal bone in patients with PT compared with the general population and are a common and treatable cause of PT [19,26,27,42]. It can be readily diagnosed with either CT temporal bone or CTA/CTV of the head [19]. One study found that SSWA was seen in all patients with venous PT in addition to other venous abnormalities [43]. IV contrast is not necessary. CT temporal bone has a smaller field-of-view and a higher resolution to evaluate the temporal bone compared with CTA.


Tinnitus

Tinnitus. Tinnitus Labyrinthine sequestrum is a very rare infective condition in which there is destruction of the inner ear structures and can cause tinnitus in addition to other symptoms. On CT, one may see erosion of the bony labyrinth. On MRI, there may be abnormal enhancement of the labyrinthine contents on the postcontrast images [44].


Tinnitus

Tinnitus. Slight modification from usual CTA bolus timing can allow for a balanced phase examination facilitating detection of both arterial and venous etiologies of PT in the head and neck. Therefore, it is the imaging modality of choice in patients with PT without a suspected retrotympanic lesion because it can show both arterial and venous pathologies in the head, skull base, and neck, in addition to the bony details of the temporal bone. Temporal bone anatomy is also well seen on thin bone window reconstructions, which cannot be assessed on MRA/MRI. Bony reconstructions from CTA thus can show SSWA such as diverticulum and wall dehiscence due to bony contour abnormalities [27]. However, 1 study reported a cause of PT being found only in 68% to 72% of patients with PT despite an extensive workup with CTA, MRI, and ultrasound (US) [12].


Tinnitus

Tinnitus. Fibromuscular dysplasia of the carotids, atherosclerotic disease, vascular dissection, and carotid aneurysms in the neck can also cause PT, which can be accurately diagnosed by CTA head and neck [1,23,28,46,49].


Tinnitus

Tinnitus. Slight modification from usual CTA bolus timing can allow for a balanced phase examination facilitating detection of both arterial and venous etiologies of PT in the head and neck. Therefore, it is the imaging modality of choice in patients with PT without a suspected retrotympanic lesion because it can show both arterial and venous pathologies in the head, skull base, and neck, in addition to the bony details of the temporal bone. Temporal bone anatomy is also well seen on thin bone window reconstructions, which cannot be assessed on MRA/MRI. Bony reconstructions from CTA thus can show SSWA such as diverticulum and wall dehiscence due to bony contour abnormalities [27]. However, 1 study reported a cause of PT being found only in 68% to 72% of patients with PT despite an extensive workup with CTA, MRI, and US [12].


Tinnitus

Tinnitus. CTA head does not cover the neck and therefore will not be able to detect the vascular abnormalities in the neck that can cause PT.


Tinnitus

Tinnitus. CTV Head With IV Contrast CTV can readily show various venous causes of PT such as transverse sinus stenosis and SSWA such as dehiscence and diverticulum. Transverse sinus stenosis, sigmoid sinus diverticulum, and sigmoid sinus dehiscence have been proposed as potential causes for PT [50]. Thin-section bone window reconstructions from the CTV are used to detect wall dehiscence, whereas diverticulum is seen on both CTV and bone window reconstruction images. The SSWAs are seen because of bony contour abnormalities, and contrast offers confirmatory value in diverticulum but is not imperative. SSWAs are much more frequently seen on CT temporal bones among patients with PT compared to the general population [26]. SSWAs are a known cause of vascular PT, and 4% to 32% of PT patients may have it, and they can be successfully treated by wall reconstruction or endovascular stenting [51-55].


Tinnitus

Tinnitus. Some studies have shown that the degree of transverse sinus stenosis seen on CTV correlates well with transstenotic pressure gradient measured on catheter manometry [26,43,56]. Transverse sinus stenosis could be a cause or result


Tinnitus

Tinnitus. Tinnitus of IIH or SSWA [26,56]. Approximately 60% of the patients of IIH experience tinnitus. Stent placement in transverse sinus stenosis for disabling cases of PT can be curative [57]. Abrupt change in the luminal caliber of the transverse sinus is proposed as a possible etiology for PT and can be seen on CTV of the head. Unilateral dominant size of the venous system is a normal variant in the general population but is equivocal as a causal factor for PT [45]. Venous causes of PT are more frequent than arterial causes [11]. CTV cannot detect arterial abnormalities, whereas a CTA/CTV can detect both arterial and venous abnormalities.


Tinnitus

Tinnitus. MRA Head With IV Contrast MRA head with IV contrast can diagnose dAVF, AVM, and larger glomus jugulare tumors, which can cause PT. A study on 54 patients with PT found excellent accuracy of combined MRA and MRI head without and with IV contrast to detect various pathologies causing PT such as dAVF, AVM, and paragangliomas [58]. IV contrast improves the sensitivity to detect dAVF, AVM, and vascular tumors like glomus jugulare. Time-resolved gadolinium-enhanced MRA is a useful technique in showing vessels with high temporal and spatial resolution to detect dAVFs. It is a reliable technique in the screening and surveillance of DAVF [16,18].


Tinnitus

Tinnitus. Catheter angiography has better sensitivity and may still be considered if MR studies are negative and dAVF is still suspected [1,23,29]. MRA head cannot identify bony lesions like jugular fossa dehiscence, SSWA, SSCD, intracranial mass lesions, and venous causes of PT. It is usually combined with MRI head with and without contrast for a better evaluation of intracranial pathologies which can cause PT.


Tinnitus

Tinnitus. MRA Head Without and With IV Contrast MRA head without and with IV contrast may be used to detect dAVF, AVM, larger glomus jugulare tumors, carotid dissection, and carotid cavernous fistula for evaluation of PT when otoscopy does not show a vascular retrotympanic lesion. Catheter angiography has better sensitivity and may still be considered if MR studies are negative and dAVF is still suspected [1,23,29]. MRA head cannot identify bony lesions like jugular fossa dehiscence, SSWA, SSCD, intracranial mass lesions, and venous causes of PT. It is usually combined with MRI head without and with contrast for a better evaluation of intracranial pathologies that can cause PT.


Tinnitus

Tinnitus. MRA Head Without IV Contrast MRA head without IV contrast can diagnose AVM and aberrant ICA but has less sensitivity to diagnose dAVF, smaller AVM, and small glomus tumors. MRA would not be able to diagnose bony lesions like jugular fossa dehiscence, SSWA, and SSCD, intracranial mass lesions, and venous causes of PT. MRA head without IV contrast is usually combined with MRI head with and without IV contrast for a better evaluation of intracranial pathologies, which can cause PT [58]. Source images of 3-D time-of-flight MRA and DSA can detect moderate to high-flow dAVF; however, it is not as sensitive as catheter angiography [59]. Catheter angiography has better sensitivity and may still be considered if MR studies are negative and dAVF is still suspected [1,23,29].


Tinnitus

Tinnitus. MRI Head and Internal Auditory Canal With IV Contrast There is no relevant literature to support the use of MRI head and IAC with IV contrast for evaluation of PT.


Tinnitus

Tinnitus. MRI Head and Internal Auditory Canal Without and With IV Contrast Vascular loops in contact with cranial nerve (CN) VIII are a normal variant and may be seen in up to one-third of normal patients. However, they may contribute to otological symptoms due to neurovascular compression. Patients with PT are 80 times more likely to have vascular loops in contact with CN VIII than patients without PT [60]. Heavily T2-weighted thin-section sequences of MRI head can detect the neurovascular loops in patients with PT [61,62]. Typewriter tinnitus is described as paroxysmal attacks of staccato sounds, thought to be caused by neurovascular compression of the cochlear nerve, and responds well to carbamazepine.


Tinnitus

Tinnitus. MRI can be helpful for detection and evaluation of the extension of the glomus jugulare in the internal jugular vein. Mass lesions in the IAC and posterior fossa such as schwannoma, meningioma, and endolymphatic sac tumor, are readily diagnosed by MRI. Vestibular schwannomas cause NPT more commonly than PT. Other masses can rarely cause tinnitus [49,63,64].


Tinnitus

Tinnitus. Postgadolinium 3-D images through the brain show detailed anatomy of the transverse and sigmoid dural venous sinuses and can be used to detect the transverse sinus stenosis. The sigmoid sinus diverticulum can also be seen on these images.


Tinnitus

Tinnitus. MRI 4-D flow can detect abnormal flow patterns in the transverse sinuses in patients with venous PT [65]. It was able to detect increased blood flow and blood velocity in patients who had markers of venous PT such as SSWA and transverse sinus stenosis [43].


Tinnitus

Tinnitus. Tinnitus MRI Head and Internal Auditory Canal Without IV Contrast Vascular loops in contact with CN VIII are a normal variant and may be seen in up to one-third of normal patients. However, they may contribute to otological symptoms due to neurovascular compression. Patients with PT are 80 times more likely to have vascular loops in contact with CN VIII than patients without PT [60]. Heavily T2- weighted thin-section sequences of MRI head can detect the neurovascular loops in patients with PT [61,62]. Typewriter tinnitus is described as paroxysmal attacks of staccato sounds, thought to be caused by neurovascular compression of the cochlear nerve, and responds well to carbamazepine. MRI without IV contrast can also detect some larger mass lesions like glomus jugulare and AVM that can cause PT. However, absence of contrast would limit its ability to detect smaller masses and AVM.


Tinnitus

Tinnitus. MRV Head With IV Contrast MRV head with IV contrast is a robust tool for detecting stenosis in the transverse sinuses, which could lead to tinnitus in association with IIH. Dural venous sinus stenosis could be from an intrinsic or extrinsic cause [66,67]. The source images can potentially detect a prominent sigmoid sinus diverticulum. However, MRV does not provide bony details to evaluate other pathologies that can cause PT such as sigmoid wall dehiscence and jugular foramen dehiscence.


Tinnitus

Tinnitus. MRV Head Without and With IV Contrast MRV head with IV contrast is a robust tool to detect stenosis in the transverse sinuses, which could lead to tinnitus in association with IIH as described in the previous section. However, MRV does not provide bony details to evaluate other pathologies that can cause PT such as sigmoid wall dehiscence and jugular foramen dehiscence. There is no added benefit in simultaneously performing MRV head without IV contrast also.


Tinnitus

Tinnitus. MRV Head Without IV Contrast MRV head without IV contrast can detect transverse sinus stenosis, but flow-related artifacts can limit optimal evaluation of the transverse sinus stenosis and sigmoid sinus diverticulum [56]. Arachnoid granulations can mimic transverse sinus stenosis.


Tinnitus

Tinnitus. US Duplex Doppler Carotid Artery US duplex Doppler carotid artery is useful to detect atherosclerotic narrowing of the carotids, which is a cause of PT. Atherosclerosis can lead to arterial stiffness, which is also associated with tinnitus [68]. Duplex US may be performed when there is a bruit in the neck and carotid stenosis is suspected. However, most other conditions which cause PT cannot be evaluated by US. US can also detect parameters of low flow resistance, high-flow velocity and high-flow volume in external carotid arteries in patients with suspected dAVF as a cause of PT [69]. However, sensitivity is lower than CTA, MRA, and conventional angiography.


Tinnitus

Tinnitus. US Duplex Doppler Transcranial There is no relevant literature to support the use of US duplex Doppler transcranial for evaluation of PT when otoscopy does not show a vascular retrotympanic lesion.


Tinnitus

Tinnitus. US Head There is no relevant literature to support the use of US head for evaluation of PT when otoscopy does not show a vascular retrotympanic lesion.


Tinnitus

Tinnitus. Variant 2: Pulsatile tinnitus, unilateral or bilateral; suspected retrotympanic lesion on otoscopy. Initial imaging. PT has many causes, and no single imaging study is appropriate for all patients. A diagnostic algorithm based on detailed history and clinical evaluation should progress from less invasive to more invasive imaging studies, and a targeted history and clinical assessment can have implications on the choice of imaging modality [12,19]. Otoscopic examination is extremely useful to guide the correct imaging in evaluation of the PT. When a vascular retrotympanic lesion is seen, the main differential diagnoses are glomus tympanicum, glomus jugulotympanicum, and vascular variants like aberrant ICA, dehiscent jugular foramen, and persistent stapedial artery (PSA). Otosclerosis can also appear as a pinkish retrotympanic lesion (Schwartz sign). It is extremely important to diagnose the vascular variants because inadvertent biopsy can have devastating complications. High-resolution thin-section temporal bone CT (HRCT) without IV contrast has excellent accuracy to make these diagnoses by carefully evaluating the contour of the bone and air spaces. IV contrast is not necessary to diagnose these conditions. HRCT of the temporal bone would also show some other conditions that cause PT but do not present as a vascular retrotympanic lesion. These conditions include high-riding jugular bulb, jugular bulb diverticulum, SSWA, SSCD, and Paget disease.


Tinnitus

Tinnitus. Tinnitus Arteriography Cervicocerebral There is no relevant literature to support the use of cervicocerebral arteriography for evaluation of PT when otoscopy shows a vascular retrotympanic lesion.


Tinnitus

Tinnitus. CT Head With IV Contrast There is no relevant literature to support the use of CT head with IV contrast for evaluation of PT.


Tinnitus

Tinnitus. CT Head Without and With IV Contrast There is no relevant literature to support the use of CT head without and with IV contrast for evaluation of PT.


Tinnitus

Tinnitus. CT Head Without IV Contrast There is no relevant literature to support the use of CT head without IV contrast for evaluation of PT.


Tinnitus

Tinnitus. CT Temporal Bone With IV Contrast There is no relevant literature to support the use of CT temporal bone with IV contrast for evaluation of PT when otoscopy shows a vascular retrotympanic lesion. CT temporal bone without contrast is adequate as described in the next section, and IV contrast does not offer any significant benefits in those indications. Changes in contour of air and bone in the temporal bone study are the key features in making the diagnosis.


Tinnitus

Tinnitus. CT Temporal Bone Without and With IV Contrast There is no relevant literature to support the use of CT temporal bone without and with IV contrast for evaluation of PT.


Tinnitus

Tinnitus. CT Temporal Bone Without IV Contrast CT temporal bone without IV contrast is useful as a first-line imaging modality when a vascular retrotympanic lesion is seen on otoscopic examination. Retrotympanic lesion may be because of a retrotympanic mass such as a glomus tumor (paraganglioma), or vascular variants. It is imperative to distinguish between the two to avoid unnecessary biopsies, which can have devastating complications. CT temporal bone without contrast can show masses like glomus tympanicum, otic capsule lesions such as otosclerosis, or vascular variants like aberrant or lateralized internal carotid artery (ICA), PSA, and dehiscent jugular foramen [1,36].


Tinnitus

Tinnitus. HRCT of the temporal bone can also detect some other conditions that cause PT but do not always present as a vascular retrotympanic mass, such as otospongiosis, Paget disease, sigmoid sinus diverticulum and sigmoid sinus dehiscence, high-riding jugular bulb, and SSCD [39].


Tinnitus

Tinnitus. Tinnitus Although CTA can detect a lot of the pathologies that can be the cause of PT when there is a retrotympanic vascular lesion, CT of temporal bone can accomplish the same, and perhaps better, because of a smaller field-of-view and higher resolution, and therefore that is preferred over the CTA.


Tinnitus

Tinnitus. CTV Head With IV Contrast Thin-section bone reconstructions from the source images of the CTV provide enough resolution and details to detect bony abnormalities, vascular variants, and glomus tympanicum, which present as vascular retrotympanic lesions. Contrast is not necessary to make diagnosis of aberrant ICA, PSA, high-riding jugular bulb, dehiscent jugular foramen, or glomus tympanicum, because changes in bony and air contour in the temporal bone are sufficient to make a diagnosis. Although CTV can be used for a lot of the pathologies that can be the cause of PT when there is a retrotympanic vascular lesion, CT of temporal bone can accomplish the same, and perhaps better, because of a smaller field-of-view and higher resolution, and therefore that is preferred over the CTV.


Tinnitus

Tinnitus. MRA Head With IV Contrast There is no relevant literature to support the use of MRA head with IV contrast for evaluation of PT when otoscopy shows a vascular retrotympanic lesion. Aberrant ICA can be diagnosed by MRA head with IV contrast. However, it is not a good test to diagnose other conditions like glomus tympanicum, PSA, glomus jugulotympanicum, or dehiscent jugular foramen, which can present as vascular retrotympanic lesions.


Tinnitus

Tinnitus. MRA Head Without and With IV Contrast There is no relevant literature to support the use of MRA head without and with IV contrast for evaluation of PT when otoscopy shows a vascular retrotympanic lesion.


Tinnitus

Tinnitus. MRA Head Without IV Contrast There is no relevant literature to support the use of MRA head without IV contrast for evaluation of PT when otoscopy shows a vascular retrotympanic lesion. Aberrant ICA can be diagnosed by MRA head without IV contrast. However, it is not a good test to diagnose other conditions like glomus tympanicum, PSA, glomus jugulotympanicum, or dehiscent jugular foramen, which can present as vascular retrotympanic lesions.


Tinnitus

Tinnitus. MRI Head and Internal Auditory Canal With IV Contrast There is no relevant literature to support the use of MRI head and IAC with IV contrast for evaluation of PT when a retrotympanic lesion is suspected on otoscopy.


Tinnitus

Tinnitus. MRI Head and Internal Auditory Canal Without and With IV Contrast The usual etiologies for vascular retrotympanic lesions are glomus tympanicum, glomus jugulotympanicum, aberrant ICA, PSA, and dehiscent jugular bulb. Small glomus tympanicum and glomus jugulotympanicum may be difficult to see on the MRI head and are easily seen on the CT temporal bone. There is no relevant literature to support the use of MRI head for detection of vascular variants that may present as vascular retrotympanic lesions.


Tinnitus

Tinnitus. MRI Head and Internal Auditory Canal Without IV Contrast The usual etiologies for vascular retrotympanic lesions are glomus tympanicum, glomus jugulotympanicum, aberrant ICA, PSA, and dehiscent jugular bulb. Tiny glomus tympanicum may be difficult to see on the MRI head and are easily seen on the CT temporal bone. There is no relevant literature to support the use of MRI head for detection of vascular variants that may present as vascular retrotympanic lesions.


Tinnitus

Tinnitus. MRV Head With IV Contrast There is no relevant literature to support the use of MRV head with IV contrast for evaluation of PT when a retrotympanic lesion is suspected on otoscopy.


Tinnitus

Tinnitus. MRV Head Without and With IV Contrast There is no relevant literature to support the use of MRV head without and with IV contrast for evaluation of PT when a retrotympanic lesion is suspected on otoscopy.


Tinnitus

Tinnitus. MRV Head Without IV Contrast There is no relevant literature to support the use of MRV head without contrast for evaluation of PT when a retrotympanic lesion is suspected on otoscopy.


Tinnitus

Tinnitus. US Duplex Doppler Carotid Artery There is no relevant literature to support the use of US duplex doppler carotid artery for evaluation of PT when a retrotympanic lesion is suspected on otoscopy.


Tinnitus

Tinnitus. Tinnitus US Duplex Doppler Transcranial There is no relevant literature to support the use of US duplex doppler transcranial for evaluation of PT when otoscopy shows a vascular retrotympanic lesion.


Tinnitus

Tinnitus. US Head There is no relevant literature to support the use of US head for evaluation of PT when otoscopy shows a vascular retrotympanic lesion.


Tinnitus

Tinnitus. Arteriography Cervicocerebral There is no relevant literature to support the use of conventional arteriography for evaluation of unilateral NPT.


Tinnitus

Tinnitus. CT Head with IV Contrast There is no relevant literature to support the use of CT head with IV contrast for evaluation of unilateral NPT.


Tinnitus

Tinnitus. CT Head Without and With IV Contrast There is no relevant literature to support the use of CT head without and with IV contrast for evaluation of unilateral NPT.


Tinnitus

Tinnitus. CT Head Without IV Contrast There is no relevant literature to support the use of CT head without IV contrast for evaluation of unilateral NPT.


Tinnitus

Tinnitus. CT Temporal Bone With IV Contrast CT temporal bone with IV contrast may be considered in a few patients if they need imaging to evaluate for retrocochlear pathology and MRI cannot be performed. Larger mass lesions such as vestibular schwannomas and meningiomas can be seen. However, small lesions, especially when located in the IAC rather than the cerebellopontine angle cistern, can be missed on CT because of the limited contrast resolution.


Tinnitus

Tinnitus. Middle ear adenomatous tumors are rare tumors in the middle ear that can cause NPT. They show significant contrast enhancement on CT and MRI but no vascular blush on angiography [70]. Otoscopic examination reveals a retrotympanic mass.


Tinnitus

Tinnitus. CT Temporal Bone Without and With IV Contrast There is no relevant literature to support the use of CT temporal bone without and with IV contrast for evaluation of unilateral NPT.


Tinnitus

Tinnitus. CT Temporal Bone Without IV Contrast CT can diagnose cochlear nerve aperture stenosis, which is associated with cochlear nerve hypoplasia, a condition in which patients can present with sensorineural hearing loss and tinnitus [75]. CT temporal bone is considered if


Tinnitus

Tinnitus. Tinnitus chronic inflammation in the middle ear is suspected to differentiate otitis media from cholesteatoma [76]. It can also be considered for abnormalities of the vestibular aqueduct.


Tinnitus

Tinnitus. CTA Head and Neck With IV Contrast There is no relevant literature to support the use of CTA head and neck with IV contrast for evaluation of unilateral NPT.


Tinnitus

Tinnitus. CTA Head With IV Contrast There is no relevant literature to support the use of CTA head with IV contrast for routine evaluation of unilateral NPT.


Tinnitus

Tinnitus. CTV Head With IV Contrast There is no relevant literature to support the use of CTV head with IV contrast for evaluation of unilateral NPT.


Tinnitus

Tinnitus. MRA Head With IV Contrast There is no relevant literature to support the use of MRA head with IV contrast for evaluation of unilateral NPT.


Tinnitus

Tinnitus. MRA Head Without and With IV Contrast There is no relevant literature to support the use of MRA head without and with IV contrast for evaluation of unilateral NPT.


Tinnitus

Tinnitus. MRA Head Without IV Contrast There is no relevant literature to support the use of MRA head without IV contrast for evaluation of unilateral NPT.


Tinnitus

Tinnitus. MRI Head and Internal Auditory Canal With IV Contrast There is no relevant literature to support the use of MRI head and IAC with IV contrast for evaluation of unilateral NPT. The study should be performed without and with IV contrast as described in the next section.