Pelvic Floor Dysfunction in Females

Pelvic Floor Dysfunction in Females. Finally, anatomic evaluation of the peripheral nerves with MR neurography may play a role in assessment of chronic or recurrent pain in patients after surgery. Although there are no studies evaluating the utility of gadolinium IV contrast after surgical repair in the pelvic floor, certain complications such as collections or fistula may be better depicted after contrast as is the case in other parts of the body. Thus, MRI of the pelvis with gadolinium IV contrast is a preferred examination for depiction of the majority of subacute or chronic complications after surgical repair of pelvic floor. US Pelvis Transabdominal Postoperative complications such as urinary retention and acute retropubic hematomas can be assessed with US; however, to our knowledge, there is no relevant literature regarding the use of TAUS for subacute or chronic complications of pelvic floor surgical repair. US Pelvis Transperineal TPUS images are obtained via cine loops in multiple planes during rest, strain, and Kegel maneuvers with both 2- D and 3-D imaging for anatomic and functional pelvic floor assessment. Patients may be positioned semi-upright or in the dorsal lithotomy position. With regard to anatomic evaluation, TPUS can detect levator muscle avulsion both before and after surgical repair for POP [47]. TPUS can visualize urethral bulking agents, urethral slings, and vaginal mesh [107]. TPUS is more sensitive for locating mesh and sling material compared with physical examination and urethrocystoscopy [112]. TPUS with tomographic reconstructions has been used to assess the location of midurethral slings after surgery [113]. Anterior and posterior components of sacrocolpopexy vaginal mesh can be seen with TPUS; however, evaluation of apical and cranial components of the sacrocolpopexy mesh is limited on TPUS [114]. TPUS is not able to visualize retropubic components of urethral slings or extrapelvic components of slings or mesh that traverse the obturator foramen or ischiorectal fossa.


Infective Endocarditis

Infective Endocarditis.  Introduction/Background Infective endocarditis can involve a normal, abnormal, or prosthetic cardiac valve. In recent years, infective endocarditis of normal right-sided valves has become more frequent because of intravenous (IV) injection of illicit drugs, indwelling IV catheters, and implantable cardiac devices [1-3]. In patients with implanted cardiac devices, it has become increasingly important to consider infections of the device leads, device generator, and device pocket [4]. The clinical presentation of endocarditis is heterogeneous, with patients often presenting with acute heart failure due to severe valve destruction, but many presenting insidiously. The physical examination often reveals a new heart murmur, most commonly due to valvular insufficiency, and evidence of heart failure or a myriad of potential embolic and inflammatory/immune-mediated sequelae. At the first clinical suspicion of infective endocarditis, the workup typically includes serial blood cultures and transthoracic echocardiography (TTE) [5,6]. Although infective endocarditis is typically diagnosed clinically with persistently positive blood cultures in association with characteristic symptoms and physical findings [5,7], and then further evaluated by echocardiography, blood cultures may be negative in the setting of antibiotic use. Imaging is used to support the diagnosis by demonstrating vegetations of cardiac valves and, in complicated cases, paravalvular abscesses affecting native [8] and prosthetic [9] valves. Imaging is also used to assess the severity of valvular damage, identify complications, recognize the presence and severity of heart failure, and inform the next steps in patient management [7,10]. 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


Infective Endocarditis

Infective Endocarditis. aResearch Author, VA Palo Alto Health Care System, Palo Alto, California and Stanford University, Stanford, California. bKaiser Permanente, Los Angeles, California. cPanel Chair, Duke University Medical Center, Durham, North Carolina. dPanel Vice-Chair, Massachusetts General Hospital, Boston, Massachusetts. eUniversity of Louisville School of Medicine, Louisville, Kentucky. fUniversity of Utah, Department of Radiology and Imaging Sciences, Salt Lake City, Utah. gThe University of Chicago Medical Center, Chicago, Illinois; American College of Physicians. hQueen's University, Kingston, Ontario, Canada; Cardiology expert. iUniversity of California San Diego, San Diego, California. jHarvard Medical School, Boston, Massachusetts. kCleveland Clinic, Cleveland, Ohio; American College of Emergency Physicians. lNaval Medical Center Portsmouth, Portsmouth, Virginia. mMassachusetts General Hospital, Boston, Massachusetts. nUniversity of Virginia Health Center, Charlottesville, Virginia; Society of Cardiovascular Computed Tomography. oAscension Healthcare Wisconsin, Milwaukee, Wisconsin; Nuclear cardiology expert. pMedstar Washington Hospital Center, Georgetown University, Washington, District of Columbia; Society for Cardiovascular Magnetic Resonance. qSpecialty Chair, UT Southwestern Medical Center, Dallas, Texas. The American College of Radiology seeks and encourages collaboration with other organizations on the development of the ACR Appropriateness Criteria through representation of such organizations on expert panels. Participation on the expert panel does not necessarily imply endorsement of the final document by individual contributors or their respective organization. Reprint requests to: publications@acr.org Infective Endocarditis required element. This corresponds to the definitions that the CMS has applied to the Current Procedural Terminology codes. OR Discussion of Procedures by Variant Variant 1: Suspected infective endocarditis. Initial imaging.


Infective Endocarditis

Infective Endocarditis. Arteriography Coronary There is limited evidence in the literature for the use of catheterization for assessing patients with suspected infective endocarditis. The primary indication is for presurgical evaluation of the coronary arteries [12]. CT Chest There is limited evidence in the literature for the use of CT chest to assess patients with suspected infective endocarditis. The primary role of CT chest is in evaluating pulmonary complications of infective endocarditis and can be particularly helpful in right-sided endocarditis for demonstrating septic pulmonary infarcts and abscesses [13,14]. CT Heart Function and Morphology CT is less accurate than TTE and transesophageal echocardiography (TEE) for identifying valvular vegetation. Consequently, the primary role of CT is in evaluating complications of infective endocarditis such as paravalvular and myocardial abscesses and pseudoaneurysms [15-20]. In depicting aortic valve pseudoaneurysms, one study showed a sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 100%, 87.5%, 91.7%, and 100%, respectively [18]. The primary weakness of CT is in detecting native aortic valve vegetations <1 cm in size for which the NPV was 55.5%. However, the sensitivity, specificity, PPV, and NPV were all 100% for vegetations >1 cm in size [18]. One study also showed CT to lack sensitivity for detecting valve perforations when compared with TEE [17]. Compared with echocardiography, CT may be superior in both detecting and visualizing the full extent of a paravalvular abscess, pseudoaneurysm, or fistula, particularly in patients with prosthetic valves [7,10,20-23]. CT may be equivalent or superior to echocardiography in identifying vegetations and valve dehiscence in suspected prosthetic valve endocarditis [7,22,24]. CT may also be utilized to assess for abnormalities in the mobility of mechanical heart valves [24].


Infective Endocarditis

Infective Endocarditis. CTA Chest There is limited evidence in the literature for the use of CTA chest for assessing patients with suspected infective endocarditis. The primary role of CTA chest is in evaluating complications of infective endocarditis such as septic pulmonary infarcts and abscesses as well as paravalvular abscess, depending on CTA acquisition technique [13,14]. CTA Coronary Arteries There is limited evidence in the literature for the use of coronary CTA (CCTA) for assessing patients with suspected infective endocarditis. CCTA has a role in preoperative planning and assessment of coronary artery disease before surgery [15,17], wherein the risks of selective coronary angiography may be considerable. Given the well- established high NPV of CCTA, its use for the presurgical assessment of significant coronary artery disease allows for a noninvasive alternative to cardiac catheterization [15,25,26]. Although the use of CCTA and CT-derived fractional flow reserve has not been studied in a patient population with suspected infective endocarditis, extrapolating from the available literature suggests that selective CT-derived fractional flow reserve in patients found to have coronary artery disease on CCTA may play a role in guiding treatment decisions [27,28]. Infective Endocarditis FDG-PET/CT Heart There is limited evidence in the literature for the use of fluorine-18-2-fluoro-2-deoxy-D-glucose (FDG)-PET/CT in suspected infective endocarditis. One prospective study showed a low sensitivity of 39% for diagnosing infective endocarditis when compared with the modified Duke criteria [29]. Another retrospective study showed a sensitivity of 0% for diagnosing native valve endocarditis when compared with the modified Duke criteria [30]. Some recent studies have shown potential clinical value of FDG-PET/CT in infective endocarditis [31].


Infective Endocarditis

Infective Endocarditis. A prospective study with 72 patients showed that adding abnormal FDG uptake around a prosthetic valve to the modified Duke criteria at admission increased the sensitivity for the diagnosis of prosthetic valve endocarditis from 70% to 97% [32]. Another smaller prospective study showed that adding PET/CT to the modified Duke criteria in patients with an intermediate probability of infective endocarditis and an implantable cardiac device increased diagnostic accuracy [33]. However, when looking at a cohort of patients with native and prosthetic valves, one study showed a relatively low sensitivity of 39% for the diagnosis of infectious endocarditis [29]. Another retrospective study showed a sensitivity of 0% for diagnosing native valve endocarditis when compared with the modified Duke criteria [30]. In patients with congenital heart disease and intravascular or intracardiac prosthetic material, one prospective study showed that the use of PET/CT in addition to the modified Duke criteria, increased the diagnostic accuracy from 61.2% to 85.1% [34]. Fluoroscopy Heart There are no data to support the use of cardiac fluoroscopy in suspected infective endocarditis. On rare occasions, cardiac fluoroscopy may be indicated for evaluating mechanical prosthetic cardiac valves afflicted with endocarditis [35]. Valve fluoroscopy is used to detect excess mobility of the mechanical prosthetic valve during the cardiac cycle (a finding highly suggestive of valve dehiscence due to infective endocarditis) or to detect immobility of mechanical prosthetic valve leaflets secondary to infected pannus or thrombus. WBC Scan Heart White blood cells (WBCs) may be labeled with either indium-111 (In-111), Tc-99m, or gallium-67 (Ga-67) [36]. There is limited evidence in the literature for the use of WBC scans in suspected infective endocarditis. One center reported a sensitivity of 0% for the detection of valvular vegetations by In-111 WBC in 7 patients with known vegetations seen by TEE [37].


Infective Endocarditis

Infective Endocarditis. Radiography Chest The chest radiograph is used to determine cardiac chamber size and the presence and severity of pulmonary venous hypertension and edema. It is also used to monitor the severity of the hemodynamic consequences of valvular regurgitation caused by infective endocarditis and to assess the response to treatment. In right-sided endocarditis, the chest radiograph may be effective in demonstrating pulmonary infarcts and abscesses as sequelae of septic emboli. US Echocardiography Transthoracic Resting TTE resting plays an important role in the evaluation of infective endocarditis and is currently the only imaging criterion included in the modified Duke criterion used for a diagnosis of infective endocarditis [39]. It can demonstrate vegetations on cardiac valves, valvular regurgitation, and paravalvular abscess. It is the most frequently used imaging study for confirming the diagnosis of infective endocarditis. The demonstration of vegetations by echocardiography is 1 of the 2 major modified Duke criteria required for the diagnosis of a definite endocarditis [39,40]. Studies show that criteria for the diagnosis, which include the findings on TTE [40,41], were significantly better than traditional criteria based on clinical and bacteriologic criteria. Several studies evaluated the diagnostic value of TTE and TEE in relation to the pretest probability of infective endocarditis based on clinical assessment in pediatric [42] and adult [43] patients. These studies concluded that Infective Endocarditis TTE has a lower yield in patients with low probability of endocarditis. TEE is the procedure of choice for patients with intermediate or high probability of endocarditis. In right-sided endocarditis, TTE and TEE performed comparably, demonstrating similar numbers of vegetations and frequency of tricuspid regurgitation [1,44].


Infective Endocarditis

Infective Endocarditis. In left-sided native valve Staphylococcus aureus endocarditis, the presence of an intracardiac abscess and left ventricular ejection fraction <40% on echocardiography have been shown to be independent predictors of in- hospital mortality [45]. In this same group of patients, intracardiac abscess and valve perforation on echocardiography have been shown to be independent predictors of 1-year mortality [45]. One large retrospective study has shown that in low- to intermediate-risk patients using a strict negative criterion on TTE beyond the absence or presence of valvular vegetations increases the sensitivity and NPV of TTE (sensitivity: 98% versus 43%; NPV: 97% versus 87%) [46]. US Echocardiography Transesophageal TEE plays an important role in the evaluation of infective endocarditis [39]. It is used in suspected infective endocarditis to directly identify or exclude valvular vegetations, paravalvular abscess, and valvular regurgitation [47,48]. It is the most sensitive imaging technique for identifying vegetations, the presence of which is the hallmark for a definitive diagnosis of infective endocarditis [40]. Ultrasound (US) diagnosis of infective endocarditis provides better diagnostic accuracy than using clinical criteria alone [41]. TEE has been shown to have up to a 98.6% NPV in suspected infective endocarditis [49]. TEE has better sensitivity than TTE for detecting vegetations [40]. TEE has better sensitivity and accuracy than TTE for identifying paravalvular abscesses [40]. TEE is indicated for suspected infective endocarditis of prosthetic valves; it is significantly more accurate than TTE [40]. Authors of a review in 2010 noted that TEE has sensitivity and specificity of >90% for detecting intracardiac lesions associated with infective endocarditis [40]. Several studies evaluated the diagnostic value of TTE and TEE in relation to the pretest probability of infective endocarditis based on clinical assessment in pediatric [42] and adult [43] patients.


Infective Endocarditis

Infective Endocarditis. These studies concluded that TTE has a lower yield in patients with low probability of endocarditis. TEE is the procedure of choice for patients with intermediate or high probability of endocarditis. Although TEE has been shown to have significantly higher sensitivity than TTE for identifying vegetations [40], specificities were similar at 91% to 100% for TEE and 91% to 98% for TTE. In right-sided endocarditis, TTE and TEE performed comparably, demonstrating similar numbers of vegetations and frequency of tricuspid regurgitation [1,44]. The size and other characteristics of vegetations on echocardiography have been shown to be useful in predicting complications such as peripheral embolization [50]. In left-sided native valve S. aureus endocarditis, the presence of an intracardiac abscess and left ventricular ejection fraction <40% on echocardiography has been shown to be independent predictors of in-hospital mortality [45]. In this same group of patients, intracardiac abscess and valve perforation on echocardiography have been shown to be independent predictors of 1-year mortality [45]. Variant 2: Known or suspected infective endocarditis. Additional imaging to direct patient management or treatment. Arteriography Coronary The primary role of catheterization is for the presurgical evaluation of the coronary arteries [7,12]. It may be used to assess the severity of valvular dysfunction and ventricular function, but this use has largely been replaced by echocardiography [12]. CT Chest The primary role of CT chest is in evaluating complications of infective endocarditis after a diagnosis has been made. Routine CT chest can be helpful in right-sided endocarditis for demonstrating septic pulmonary infarcts and abscesses, osteomyelitis, and for preoperative assessment and surgical planning [25]. CT Heart Function and Morphology The primary role of CT heart is in evaluating complications of infective endocarditis such as paravalvular and myocardial abscesses and pseudoaneurysms [15-20,51].


Infective Endocarditis

Infective Endocarditis. In depicting aortic valve pseudoaneurysms, one study showed a sensitivity, specificity, PPV, and NPV of 100%, 87.5%, 91.7%, and 100%, respectively [18]. Compared with echocardiography, CT may be superior in both detecting and visualizing the full extent of a paravalvular Infective Endocarditis abscess, pseudoaneurysm, or fistula, particularly in patients with prosthetic valves [7,10,20-23]. CT may be equivalent or superior to echocardiography in identifying vegetations and valve dehiscence in suspected prosthetic valve endocarditis [7,22,24]. CT may also be utilized to assess for abnormalities in the mobility of mechanical heart valves and to identify causes of mechanical valve dysfunction that are missed on echocardiography and fluoroscopy [24]. CTA Chest The primary role of CTA chest is in evaluating complications of infective endocarditis such as septic pulmonary infarcts and abscesses, paravalvular abscess depending on CTA acquisition technique [13,14], and aortic pseudoaneurysms. CTA chest can also be helpful for preoperative assessment of vasculature and surgical planning [25]. CTA Coronary Arteries CCTA has a role in preoperative planning and assessment of coronary artery disease before surgery [15,17], where the risks of selective coronary angiography may be considerable. Given the well-established high NPV of CCTA, its use for the presurgical assessment of significant coronary artery disease allows for a noninvasive alternative to cardiac catheterization [15,25,26]. Although the use of CCTA and CT-derived fractional flow reserve has not been studied in a patient population with suspected infective endocarditis, extrapolating from the available literature suggests that selective CT-derived fractional flow reserve in patients found to have coronary artery disease on CCTA may play a role in guiding treatment decisions [27,28]. FDG-PET/CT Heart Some recent studies have shown potential clinical value of FDG-PET/CT in infective endocarditis [31].


Infective Endocarditis

Infective Endocarditis. One study showed that FDG-PET/CT detected clinically unsuspected sites of extracardiac infection in up to 24% of cases [52]. Several single-center studies have shown promise in identifying cardiovascular implantable electronic device infections using FDG-PET/CT with sensitivities ranging from 60% to 100% and specificities ranging from 86% to 100% [4,53-55]. In cases in which TTE and TEE were normal or equivocal, 2 studies showed that FDG-PET/CT was able to detect periprosthetic abscesses [56,57], which has been shown to occur in nearly 30% of cases [47]. Fluoroscopy Heart Cardiac fluoroscopy may be indicated for evaluating mechanical prosthetic cardiac valves afflicted with endocarditis [35]. Valve fluoroscopy is used to detect excess mobility of the mechanical prosthetic valve during the cardiac cycle (a finding highly suggestive of valve dehiscence due to infective endocarditis) or to detect immobility of mechanical prosthetic valve leaflets secondary to infected pannus or thrombus. WBC Scan Heart WBCs may be labeled with either In-111, Tc-99m, or Ga-67 [36]. This may be used for identifying and localizing infected vegetations and paravalvular abscesses [39,58]. When echocardiography is inconclusive in suspected prosthetic valve endocarditis, a WBC scan has been shown to have a lower sensitivity than FDG-PET/CT (64% versus 93%, respectively) but a higher specificity (100% versus 71%, respectively) for the diagnosis of endocarditis [39,59]. Radiography Chest The chest radiograph is used to determine cardiac chamber size and the presence and severity of pulmonary venous hypertension and edema. It is also used to monitor the severity of the hemodynamic consequences of valvular regurgitation caused by infective endocarditis and to assess the response to treatment. In right-sided endocarditis, the chest radiograph may be effective in demonstrating pulmonary infarcts and abscesses as sequelae of septic emboli. Infective Endocarditis


Asymptomatic Patient at Risk for Coronary Artery Disease PCAs.  Introduction/Background In the United States, atherosclerotic cardiovascular disease (ASCVD) remains the leading cause of death for both men and women [1]. Although improvements in awareness, knowledge, and medications have led to a decrease in death rates, the burden of disease remains very high [1,2]. Identification of patients who may benefit from early intervention prior to development of symptoms has been shown to reduce mortality and morbidity [3]. There is a well-established discordance between the prognostic accuracy of current risk estimation scores versus imaging when directly measuring the burden of atherosclerosis for the assessment of individual ASCVD risk as a guide to optimally manage preventive therapies [6]. Imaging allows for the detection of subclinical coronary atherosclerosis. Patients with familial hyperlipidemia in particular have a high prevalence of subclinical coronary atherosclerosis that is independently associated with cardiovascular risk [7]. The coronary artery calcium (CAC) score is a validated measure of overall coronary atherosclerotic burden, the strongest known imaging measure of risk in asymptomatic individuals. Individual data derived from this and other imaging tests provide useful prognostic information for patient management and can complement current risk prediction models [8]. The purpose of this document is to discuss the use of diagnostic imaging tests in asymptomatic patients who are at elevated risk of future cardiovascular events related to atherosclerosis. The tests are to improve targeted preventive efforts based on patient risk and are aimed at identification of CAD. aPanel Vice-Chair, Massachusetts General Hospital, Boston, Massachusetts. bResearch Author, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts. cPanel Chair, Duke University Medical Center, Durham, North Carolina. dUniversity of Louisville School of Medicine, Louisville, Kentucky.


Asymptomatic Patient at Risk for Coronary Artery Disease PCAs. eUniversity of Utah, Department of Radiology and Imaging Sciences, Salt Lake City, Utah. fThe University of Chicago Medical Center, Chicago, Illinois; American College of Physicians. gKaiser Permanente, Los Angeles, California. hSanger Heart and Vascular Institute, Charlotte, North Carolina; Cardiology Expert. iUniversity of Washington, Seattle, Washington. jUniversity of California San Diego, San Diego, California. kHarvard Medical School, Boston, Massachusetts. lNaval Medical Center Portsmouth, Portsmouth, Virginia. mMassachusetts General Hospital, Boston, Massachusetts. nLoyola University Medical Center, Maywood, Illinois; Society for Cardiovascular Magnetic Resonance. oUniversity of Virginia Health Center, Charlottesville, Virginia; Society of Cardiovascular Computed Tomography. pAscension Healthcare Wisconsin, Milwaukee, Wisconsin; Nuclear Cardiology Expert. qSpecialty Chair, UT Southwestern Medical Center, Dallas, Texas. The American College of Radiology seeks and encourages collaboration with other organizations on the development of the ACR Appropriateness Criteria through representation of such organizations on expert panels. Participation on the expert panel does not necessarily imply endorsement of the final document by individual contributors or their respective organization. Reprint requests to: publications@acr.org Asymptomatic Patient at Risk for CAD Resting image modalities (ultrasound [US], scintigraphy, CT, and MRI) depict late findings of CAD, such as ventricular dilatation and wall-motion abnormalities, and can directly visualize the morphology of infarcted myocardial segments. Intravascular US, an invasive technique, can detect both calcified and noncalcified plaque.


Asymptomatic Patient at Risk for Coronary Artery Disease PCAs. Myocardial perfusion can be assessed by stress, rest, and/or delayed imaging, which can be accomplished by US (via assessment of wall-motion changes at stress versus rest, or with contrast echocardiography); cardiac perfusion scintigraphy (via comparison of first-pass radiotracer perfusion to the ventricle at stress versus rest, or measurement of coronary blood flow); and MRI (via comparison of wall-motion or first-pass gadolinium enhancement of the ventricle during stress versus rest). Cardiac MRI is performed with ECG synchronization and may be performed without and with IV contrast and before and after vasodilators or inotropes if stress myocardial perfusion assessment is desired. MR angiography (MRA) of the coronary arteries is possible without or with IV contrast, but it only depicts luminal blood and cannot depict calcified plaque. Myocardial scarring, infarction, and viability can be assessed by cardiac MRI or cardiac PET. All elements are essential: 1) timing, 2) reconstructions/reformats, and 3) 3-D renderings. Standard CTs with contrast also include timing issues and reconstructions/reformats. Only in CTA, however, is 3-D rendering a required element. This corresponds to the definitions that the CMS has applied to the Current Procedural Terminology codes. OR Discussion of Procedures by Variant Variant 1: Asymptomatic patient. Low risk for coronary artery disease. Initial imaging. CT Coronary Calcium The CAC score first became available and validated with electron beam CT, and in the modern era, MDCT is used to acquire this data. Several multicenter trials have assessed the use of CAC in asymptomatic patients at intermediate risk for CAD. In the Multi-Ethnic Study of Atherosclerosis (MESA), Joshi et al [14] followed 6,814 participants CTA Coronary Arteries There is no relevant literature supporting the use of coronary CTA (CCTA) in asymptomatic patients at low risk of CAD.


Asymptomatic Patient at Risk for Coronary Artery Disease PCAs. Choi et al [19] identified atherosclerotic plaques in 215 of 1,000 middle-aged asymptomatic patients with 2% prevalence of plaque in the low-risk group. US Echocardiography Transthoracic Resting There is no relevant literature supporting the use of transthoracic echocardiography (TTE) resting in asymptomatic patients at low risk of CAD. US Echocardiography Transthoracic Stress There is no relevant literature supporting the use of TTE stress in asymptomatic patients at low risk of CAD. The sensitivity and specificity of the test is 72% to 83% and 84% to 95%, respectively, for identification of ischemic myocardium and has been validated only in elevated risk populations [20]. MRI Heart Function with Stress There is no relevant literature supporting the use of MRI heart function with stress in asymptomatic patients at low risk of CAD. MRI Heart Function and Morphology Weir-McCall et al [22] demonstrated an overall low utility of resting MRI via abnormal late gadolinium enhancement in asymptomatic low-risk volunteers (0.67% of whom were found to have abnormalities, including myocardial infarction), with only 0.2% of volunteers having a previously unrecognized myocardial infarction. Radiography Chest There is no relevant literature to support the use of chest radiographs to evaluate asymptomatic patients at low risk of CAD. Asymptomatic Patient at Risk for CAD Variant 2: Asymptomatic patient. Intermediate risk for coronary artery disease. Initial imaging. CT Coronary Calcium Kondos et al [24] found that any measurable coronary calcium was independently related to hard (death and myocardial infarction) and soft (revascularization procedure) events in men and women at low to intermediate pretest risk; this finding provided incremental prognostic information over conventional risk factors.


Asymptomatic Patient at Risk for Coronary Artery Disease PCAs. CTA Coronary Arteries In a recent study, Di Cesare et al [33] showed utility of CCTA in asymptomatic patients at intermediate risk of stenosis detection in 112 out of 185 (60.5%) patients: 56 patients (30.2%) had mild stenosis, 49 patients (26.5%) had moderate stenosis, only 3 patients (1.6%) had severe stenosis, and in 4 patients (2.2%) evaluation could not be determined. US Echocardiography Transthoracic Resting There is no relevant literature supporting the use of TTE resting in asymptomatic patients at intermediate risk of CAD. Asymptomatic Patient at Risk for CAD US Echocardiography Transthoracic Stress The sensitivity and specificity of stress TTE is 85% and 89%, respectively, has been validated only in populations at elevated risk, and is best utilized to search for obstructive major epicardial coronary stenosis [34]. There is no relevant literature to support the use of stress TTE in asymptomatic patients at intermediate risk of CAD. MRA Coronary Arteries MRA of the coronary arteries can assess for arterial patency and pathologic wall thickening but not calcific burden, and it cannot reliably assess small distal vessels [35,36]. There is no relevant literature to support the use of MRA of the coronary arteries in asymptomatic patients at intermediate risk of CAD. MRI Heart Function and Morphology There is no relevant literature to support the use of MRI heart function and morphology to evaluate asymptomatic patients at intermediate risk of CAD. MRI Heart Function with Stress The IMPACT II study demonstrated a sensitivity of 67% and specificity of 61% for detection of ischemic heart disease, including 533 patients in the intermediate-risk population [37]. The vast majority of the patients in this study were symptomatic, with angina pectoris. The sensitivity and specificity of the test in the asymptomatic intermediate-risk population has not been validated.


Asymptomatic Patient at Risk for Coronary Artery Disease PCAs. Radiography Chest There is no relevant literature to support the use of chest radiographs alone as a test to evaluate asymptomatic patients at intermediate risk of CAD. Asymptomatic Patient at Risk for CAD plaque only seen on CTA. With a mean follow-up period of 2.65 years, MACE rate was 0% in CAD negative and higher (1.2%) in CAD positive by CTA. In a large multicenter registry of 27,125 patients (which included both symptomatic and asymptomatic patients), Min et al [45] found that CCTA improved discrimination by maximal stenosis, number of obstructive vessels, and segment stenosis score (C-index 0.77, 0.77, and 0.78, respectively) beyond age, gender, and CAC score (C-index 0.64) in a small subset of 400 asymptomatic patients. Similarly, CCTA findings improved risk reclassification by per patient maximal stenosis (integrated discrimination improvement [IDI] index, 0.03; P = . 03) and number of obstructive vessels (IDI index, 0.06; P = . 002), and by trend for segment stenosis score (IDI, 0.03; P = . 06). US Echocardiography Transthoracic Resting There is no relevant literature supporting the use of resting TTE in asymptomatic patients at high risk of CAD. US Echocardiography Transthoracic Stress TTE performed at rest and stress can assess for inducible wall-motion abnormalities, thus revealing ischemic heart disease. The sensitivity and specificity of the test is 72% to 83% and 84% to 95%, respectively, and has been validated only in symptomatic elevated risk populations and is best utilized to identify obstructive major epicardial coronary stenosis [20]. There is no relevant literature to support the use of stress TTE in asymptomatic patients at high risk of CAD. MRA Coronary Arteries MRA of the coronary arteries can assess for arterial patency and pathologic wall thickening but not calcific burden, and it cannot reliably assess small, distal vessels [35,36].


Suspected Spine Trauma Child PCAs

Suspected Spine Trauma Child PCAs.  In general, the diagnostic evaluation of children with traumatic spine injury is determined by clinical findings, such as pain, limitation of movements, and neurological deficits, as well as injury mechanisms (eg, high- versus low-energy trauma mechanisms) [6]. However, the clinical assessment of spine injuries in children may be limited in unconscious or intubated patients, in children with intellectual disabilities, and in children who lack the ability to communicate because of their developmental stage (typically <2 years of age) [7,8]. Two major clinical decision rules, the National Emergency X-Radiography Utilization Study (NEXUS) criteria [13] and the Canadian C-Spine Rule [14], were demonstrated to have high negative predictive values (97% and 100%, respectively) to rule out cervical spine injury in adults without the need for imaging. The first NEXUS validation study [15] included children, but the sample size was small and there were few young children with cervical spine injury and none <2 years of age. A later pediatric validation study showed that no clinically important injuries were missed when the NEXUS clinical decision rule was used [16]; however, this validation study was also limited by a low incidence of cervical spine injury and small numbers of very young children [17]. The American College of Radiology seeks and encourages collaboration with other organizations on the development of the ACR Appropriateness Criteria through society representation on expert panels. Participation by representatives from collaborating societies on the expert panel does not necessarily imply individual or society endorsement of the final document. Reprint requests to: publications@acr.org The Pediatric Emergency Care Applied Research Network (PECARN) study identified risk factors associated with cervical spine injury in children in a large case control study [18].


Suspected Spine Trauma Child PCAs

Suspected Spine Trauma Child PCAs. The advantage of these risk factors is that they were based on a pediatric population and demonstrated 98% sensitivity. However, these risk factors have not yet been prospectively validated in a pediatric population. We decided to use the PECARN age <16 years to frame the variants in this document. There has only been one study evaluating predictors of cervical spine injury in blunt trauma in patients <3 years of age [19]. The study used a large cohort and a retrospective study design and there were no subsequent validation studies [19] (see Appendix 1). Several congenital disorders have been associated with a higher risk for cervical injury in athletes. For example, increased ligamentous laxity in patients with Down syndrome is associated with higher rates of spinal cord injury; patients with achondroplasia and spinal stenosis are at risk for significant spinal cord injury at the cervicomedullary junction with hyperflexion and hyperextension; similar injury risks related to atlantoaxial instability probably apply in patients with mucopolysaccharidosis type VI and Marfan syndrome [20]. In addition, children receiving systemic glucosteroid therapy for inflammatory diseases, such as juvenile dermatomyositis, juvenile idiopathic arthritis, systemic lupus erythematosus, systemic arthritis, and systemic vasculitis, are at higher risk for vertebral body fractures [21,22]. Children may have cartilaginous injuries that are not visualized on radiographs but are better detected with MRI [24]. In adults, MRI is the modality of choice to evaluate thoracolumbar trauma patients with neurologic deficits, abnormal CT scans, and high clinical suspicion despite negative radiographic evaluation [25]. Recently, a scoring system based on injury morphology, neurological status, and integrity of the thoracolumbar posterior ligament complex has been introduced to guide treatment decisions in adults >17 years of age [26].


Suspected Spine Trauma Child PCAs

Suspected Spine Trauma Child PCAs. It was shown that MRI facilitates the ability to classify thoracolumbar fractures in adults and children [27,28]. Sacral fractures account for only 0.16% of all pediatric trauma patients [3]. In a retrospective study of 89 patients, only 5% sacral fractures were found, all of which were Denis zone 1 fractures [3], which are located lateral to the neural elements and commonly involve the sacral alae [29]. Adequate radiographs still miss 35% of sacral fractures; therefore, CT and MRI are superior to radiographs in the diagnosis of sacral fractures [29]. Imaging plays a crucial role in the detection and classification of traumatic spinal injuries in children. Failure to identify patients with an unstable spine injury and potential spinal cord compromise can lead to increased patient morbidity [7]. Conversely, the ability to identify patients without spinal injury can avoid unnecessary imaging and aids in the decision to discontinue spinal precaution protocols, which can result in skin breakdown and ulceration when used over prolonged periods of time [7]. Discussion of Procedures by Variant Variant 1: Child, 3 to 16 years of age, acute cervical spine trauma, meets low risk criteria (based on PECARN or NEXUS). Initial imaging. Radiography Cervical Spine The routine radiograph of the cervical spine in children with head trauma has a very low yield; in fact, the two cases of cervical injury in a cohort of 905 infants (0.02%) were due to an abusive trauma mechanism [4] (based on PECARN or NEXUS in Appendix 1). CT Cervical Spine In adult populations, CT is the superior screening modality for patients who are at very high risk for cervical spine injury. In children, there is no evidence in favor of replacing screening radiographs with CT in children at low risk for cervical spine injury [30].


Suspected Spine Trauma Child PCAs

Suspected Spine Trauma Child PCAs. Normal variants in young children <8 years of age, such as pseudosubluxation of C2-C3, absence of lordosis, C3 vertebral wedged appearance, widening of the atlantodental interval, prevertebral soft-tissue thickening, Young children and those with developmental delays may require sedation in order to obtain adequate CT and MR images. The risks of sedation should be balanced against the benefit of a CT, particularly when radiographs are normal [19]. MRI Cervical Spine MRI is not routinely used in the evaluation of suspected pediatric spine trauma in the absence of risk factors (based on PECARN or NEXUS in Appendix 1). Arteriography Cervicocerebral Cervicocerebral arteriography is not routinely used in the evaluation of suspected pediatric spine trauma in the absence of risk factors (based on PECARN or NEXUS in Appendix 1). US Cervical Spine Ultrasound (US) is not routinely used in the evaluation of suspected pediatric spine trauma in the absence of risk factors (based on PECARN or NEXUS in Appendix 1). CT Myelography Cervical Spine Myelography is not routinely used in the evaluation of suspected pediatric spine trauma in the absence of risk factors (based on PECARN or NEXUS in Appendix 1). For suspected ligamentous injury in conscious children, it was shown that cervical flexion and extension views in children and adults with acute blunt cervical trauma are unlikely to yield additional results [36,38-41] and are rarely needed in children [42]. Neck pain and muscle spasm may limit spinal motion of flexion and extension views in the acute setting and prevent the diagnosis of ligamentous injury from being made [34]. CT Cervical Spine CT cervical spine may be of value as a follow-up examination in patients who had radiographs with abnormal or ambiguous findings. The strengths of CT without intravenous (IV) contrast include its superior visualization of bony detail and ability to differentiate congenital variants from traumatic injuries.


Suspected Spine Trauma Child PCAs

Suspected Spine Trauma Child PCAs. Dealing with an uncooperative child may lengthen the Normal variants in children <8 years of age, such as pseudosubluxation of C2-C3, absence of lordosis, C3 vertebral wedged appearance, widening of the atlantodental interval, prevertebral soft-tissue thickening, intervertebral widening, and pseudo-Jefferson fracture, can adversely affect the accuracy of CT imaging interpretations [19]. In addition, children <8 years of age may need to be sedated to obtain adequate cross- sectional imaging studies, which carries a low complication risk [19]. Cervical ligamentous injury may remain undetected on CT imaging [19], and CT is not considered an effective modality for evaluation of this type of injury [49]. CT alone performs similarly in the classification of subaxial cervical spine injury as CT and MRI combined [50]. Fat-saturated T2-weighted MRI has been shown to be superior to CT and radiographs in children with craniocervical junction and soft-tissue injury [51]. In cases where MRI is not available or the patient cannot safely undergo MRI, CT performs similarly to MRI in the evaluation of unstable cervical trauma [52]. The spine in children >8 years of age is considered to be similar to the adult spine in that the cervical spine fulcrum is located at the C3-C4 level [12]. In this age group, the lower cervical spine is more commonly injured with trauma and may be difficult to confidently evaluate on radiographs [17]. In a study of unconscious intubated adult patients, lateral radiographs were shown to have a sensitivity of only 51.7% for unstable injuries, while CT showed sensitivity of 98.1%, specificity of 98.8%, and a negative predictive value of 99.7% [30,43]. There is no pediatric scientific literature to support the use of contrast-enhanced CT in the setting of spinal trauma, although IV contrast may be given when whole-body CT is performed to evaluate for other traumatic injuries [53-55].


Suspected Spine Trauma Child PCAs

Suspected Spine Trauma Child PCAs. MRI Cervical Spine MRI of cervical spine may be of value as a follow-up examination in patients who have an abnormal neurological examination. MRI without IV contrast is considered the reference standard for evaluation of soft tissues [48,56], although one study showed that MRI detected osseous injury in children with a sensitivity of 100% and a specificity of 97% [48]. MRI was shown to be superior to CT and radiographs in children with craniocervical junction injuries to ligaments and the spinal cord, including soft-tissue injuries that are best seen on fat-saturated T2 sequences [51]. It was shown in adults that while MRI has high sensitivity for soft-tissue injury, its lack of specificity makes it less suitable for operative decision making [45]. MRI is the modality of choice in children who fulfill criteria for myelopathy or SCIWORA [51,57-59]. It has been shown in children and adults that MRI following a completed cervical CT did not add any clinically significant information [7,60-64]. Some reports stated that adult cervical injuries were detected with MRI and not with CT and that these changed management [65,66]. A study of 45 patients showed that children with normal radiography and CT may have signs of traumatic cervical injury on MRI [51]. However, a recent meta-analysis showed that the pooled incidence of unstable injuries detected by MRI but missed on CT was 0.0029% [67]. MRI can identify vascular intramural hematomas and early ischemic spinal cord injuries and thus identify patients who may benefit from additional vascular imaging and management of ischemic complications [68]. Disadvantages include lengthy examination times in an environment where patient monitoring can be difficult. The requirement for a motion-free examination and the need for optimal positioning in children may lengthen examination times or require sedation.


Suspected Spine Trauma Child PCAs

Suspected Spine Trauma Child PCAs. There are no pediatric studies comparing IV contrast versus noncontrast MRI for the detection of spinal cord injury, but adult studies have shown that contrast-enhanced MRI may be more effective in the evaluation of severe soft-tissue injury but is not more effective for the detection of spinal cord injury [77]. CTA Neck There are currently no sufficient reports regarding outcomes of vascular imaging in children with spinal trauma. Cervical vascular injury in pediatric blunt trauma can be seen in 11.5% of pediatric patients [68]. CT angiography (CTA) has been validated against digital subtraction angiography (DSA) for imaging of cerebrovascular injury in adults, but DSA remains the reference standard [68]. When compared to DSA, CTA has the benefit of being less time intensive, having a lower risk of iatrogenic injury, and having fewer complications than those associated with DSA (such as stroke or death, arterial dissection, and vasospasm) [68,78]. CTA can also be easily performed in conjunction with other CT examinations, and the noninvasive nature of CTA makes it better suited as a screening tool in cervical trauma patients [68,78-80]. Both CTA and MR angiography (MRA) may be considered in children with cervical trauma [68]. Certain risk factors can indicate the need for vascular screening, such as fractures involving the transverse foramen, traumatic facet dislocations (with or without fracture), ligamentous injury, neurological deficits, and fractures of C1-C3 [68,80-82]. Injury patterns at C2 that are specifically associated with vertebral artery injury in adults are dens fractures and traumatic spondylolisthesis [83]. Cerebrovascular injury after blunt trauma was diagnosed with CTA in 5.8% of 137 children with blunt trauma [84]. Scoring systems to identify adult patients that should undergo vascular imaging exist, but they have not been validated in children [85]. MRA Neck In adults, the role of MRA relative to DSA is less well established [68].


Suspected Spine Trauma Child PCAs

Suspected Spine Trauma Child PCAs. Studies comparing CTA, MRA, and DSA have found that CTA has comparable accuracy compared to DSA, while MRA tended to overestimate stenosis and occlusion [68]. Lower-grade vascular injuries may be missed with CTA but not with DSA, even though they are usually asymptomatic [80]. A benefit of MRA over CTA and DSA is its ability to identify intramural hematomas and early ischemic injuries [68]. To date, despite the benefits of MRI as a noninvasive examination, the Eastern Association for the Surgery of Trauma states that MRA should not be considered as the sole imaging modality for blunt cerebrovascular injury based on lower sensitivity of MRA relative to DSA in detecting traumatic vascular injuries in adults [86]. Arteriography Cervicocerebral DSA remains the reference standard for cerebrovascular injury in adults [68]. There is no recent scientific literature evaluating the use of DSA in children with spinal trauma. DSA is more time consuming and associated with severe risks, including thrombosis, that could lead to stroke or death, arterial dissection, and vasospasm [68,78]. US Cervical Spine The value of US has only recently been explored in pediatric cervical spine trauma and is not yet established [87]. Integrity of the posterior ligamentous complex plays an integral role for stability of the spine, and presence of posterior ligamentous complex injury may indicate more severe damage and change treatment interventions [88]. MRI is the modality of choice for evaluation of the posterior ligamentous complex, but it was shown that its sensitivity and specificity are lower than previously thought [89]. CT Myelography Cervical Spine CT myelography is rarely performed and has been largely replaced with MRI. Exceptional indications may exist for patients with contraindications to MRI and in whom impending cord compression is suspected [90].


Suspected Spine Trauma Child PCAs

Suspected Spine Trauma Child PCAs. Variant 3: Child, younger than 3 years of age, acute cervical spine trauma, Pieretti-Vanmarcke weighted score greater than or equal to 2 to 8 points. Initial imaging. Radiography Cervical Spine In children <3 years of age and in children with delays or other deficits, lack of verbal and cognitive skills represents the main limiting factor for establishing appropriate imaging indications based on the clinical examination. Anatomically, in children <3 years of age the dentocentral synchondrosis is still open and the C3-C7 neural arches have not yet fused [91]. A review of the National Trauma Data Bank showed that 48% of cervical spine injuries in children <3 years of age occurred in the lower cervical spine [54]. Nonetheless, children <3 years of age on average and children in forward-facing car seats can experience odontoid fractures, particularly with rapid deceleration with flexion [91]. Radiographs in conjunction with NEXUS criteria were used to clear 80% of cervical spine injuries in a cohort of 575 patients <3 years of age [42]. Certain clinical criteria have been proposed specifically in children <3 years of age to determine the necessity of imaging [19]. A study comparing cervical spine clearance in unconscious pediatric patients using plain cervical radiographs, flexion-extension under fluoroscopy, CT, and MRI imaging found that flexion-extension fluoroscopy in children with negative cervical radiographs and/or CT imaging is superior to MRI because MRI lacks specificity with regards to differentiating ligamentous edema from rupture [44,45]. CT Cervical Spine CT cervical spine may be of value as a follow-up examination in patients who had radiographs with abnormal or ambiguous findings.


Suspected Spine Trauma Child PCAs

Suspected Spine Trauma Child PCAs. Normal variants in children <3 years of age, such as pseudosubluxation of C2-C3, absence of lordosis, C3 vertebral wedged appearance, widening of the atlantodental interval, prevertebral soft-tissue thickening, intervertebral widening, and pseudo-Jefferson fracture, can adversely affect the accuracy of CT imaging interpretations [19]. In addition, children <3 years of age may need to be sedated to obtain adequate cross- sectional imaging studies, which carries a low complication risk [19]. There is no pediatric scientific literature to support the use of contrast-enhanced CT in the setting of spinal trauma, although IV contrast may be given when whole-body CT is performed to evaluate for other traumatic injuries [53-55]. MRI Cervical Spine MRI of cervical spine may be of value as a follow-up examination in patients who have an abnormal neurological examination. The best imaging modality for evaluation of newborn spinal cord injury secondary to cervical spine trauma is MRI [92]. Neonatal spinal cord injury is a rare condition with an estimated incidence of 1 in 80,000 live births. MRI was shown to be superior to CT and radiographs in children with craniocervical junction injuries, including soft-tissue injuries that are best seen on fat-saturated T2 sequences [51]. CTA Neck There are currently no sufficient reports regarding outcomes of vascular imaging in children with spinal trauma. Cervical vascular injury in pediatric blunt trauma can be seen in 11.5% of pediatric patients [68]. CTA has been validated against DSA for imaging of cerebrovascular injury in adults, but DSA remains the reference standard [68]. When compared to DSA, CTA has the benefit of being less time intensive, having a lower risk of iatrogenic injury, and having fewer complications than those associated with DSA (such as stroke or death, arterial dissection, and vasospasm) [68,78].


Suspected Spine Trauma Child PCAs

Suspected Spine Trauma Child PCAs. CTA can also be easily performed in conjunction with other CT examinations, and the noninvasive nature of CTA makes it better suited as a screening tool in cervical trauma patients [68,78-80]. Both CTA and MRA may be considered in children with cervical trauma [68]. Certain risk factors can indicate the need for vascular screening, such as fractures involving the transverse foramen, traumatic facet dislocations (with or without fracture), ligamentous injury, neurological deficits, and fractures of C1-C3 [68,80-82]. Injury patterns at C2 that are specifically associated with vertebral artery injury in adults are dens fractures and traumatic spondylolisthesis [83]. Cerebrovascular injury after blunt trauma was diagnosed with CTA in 5.8% of 137 children with blunt trauma [84]. Scoring systems to identify adult patients that should undergo vascular imaging exist, but they have not been validated in children [85]. MRA Neck In adults, the role of MRA relative to DSA is less well established [68]. Studies comparing CTA, MRA, and DSA have found that CTA has comparable accuracy compared to DSA, while MRA tended to overestimate stenosis and occlusion [68]. Lower-grade vascular injuries may be missed with CTA but not with DSA, even though they are usually asymptomatic [80]. A benefit of MRA over CTA and DSA is its ability to identify intramural hematomas and early ischemic injuries [68]. To date, despite the benefits of MRI as a noninvasive examination, the Eastern Association for the Surgery of Trauma states that MRA should not be considered as the sole imaging Arteriography Cervicocerebral DSA remains the reference standard for cerebrovascular injury in adults [68]. There is no recent scientific literature evaluating the use of DSA in children with spinal trauma. DSA is more time consuming and associated with severe risks that include thrombosis that could lead to stroke or death, arterial dissection, and vasospasm [68,78].


Suspected Spine Trauma Child PCAs

Suspected Spine Trauma Child PCAs. US Cervical Spine The value of US has only recently been explored in pediatric cervical spine trauma and is not yet established [87]. Integrity of the posterior ligamentous complex plays an integral role for stability of the spine, and presence of posterior ligamentous complex injury may indicate more severe damage and change treatment interventions [88]. MRI is the modality of choice for evaluation of the posterior ligamentous complex, but it was shown that its sensitivity and specificity are lower than previously thought [89]. CT Myelography Cervical Spine CT myelography is rarely performed and has been largely replaced with MRI. Exceptional indications may exist for patients with contraindications to MRI and in whom impending cord compression is suspected [90]. Variant 4: Child, younger than 16 years of age, acute thoracolumbar spine trauma. Initial imaging. Radiography Thoracic and Lumbar Spine It was estimated that only 0.6% to 0.9% of all pediatric spinal injuries affect the thoracolumbar supine [93]. There are currently no national guidelines to inform clinicians whether an imaging examination would be beneficial for an individual patient or not [93]. Thoracic and lumbar spine injuries are most commonly seen in children >9 years of age [3]. The clinical diagnosis of thoracolumbar spine fractures in children is frequently difficult because the clinical assessment has only 81% sensitivity and 68% specificity [24]. This argues in favor of screening children with thoracolumbar trauma with radiographs, regardless of clinical symptoms. However, a prospective study in 50 children with thoracolumbar trauma showed that AP and lateral radiographs missed 22% of fractures when compared to MRI [24]. As shown in adults, it may be useful to screen for thoracolumbar fractures by using reconstructed spine images from chest, abdomen, and pelvis MDCT when available [94-96]. Sacral fractures account for only 0.16% of all pediatric trauma patients [3].


Suspected Spine Trauma Child PCAs

Suspected Spine Trauma Child PCAs. In a retrospective study of 89 patients, only 5% sacral fractures were found, all of which were Denis zone 1 fractures [3], which are located lateral to the neural elements and commonly involve the sacral alae [29]. Another study reported that adequate radiographs miss 35% of sacral fractures and, therefore, CT and MRI are superior to radiography in the diagnosis of sacral fractures [29]. CT Thoracic and Lumbar Spine CT spine may be of value as a follow-up examination in patients who had radiographs with abnormal or ambiguous findings. There are not sufficient data to support the routine use of MDCT without IV contrast in the clearance of pediatric blunt spinal trauma. As shown in adults, it may be useful to screen for thoracolumbar fractures by using reconstructed spine images from chest, abdomen, and pelvis MDCT, when available [94-96]. Adequate radiographs miss 35% of sacral fractures; therefore, CT and MRI are superior to radiography in the diagnosis of sacral fractures [29]. A recent study in adults showed that CT can identify posterior ligament complex injuries with satisfactory reliability, which can be useful for the classification of thoracolumbar fractures [97]. MRI Thoracic and Lumbar Spine MRI of the spine may be of value as a follow-up examination in patients who have an abnormal neurological examination. MRI without IV contrast has become the modality of choice for imaging of children with thoracolumbar trauma and is especially useful in detecting injuries that require surgical intervention and that may be missed on CT, such as epidural hematoma or traumatic disk herniation [93]. SCIWORA is more common in children <8 years of age and mostly affects the cervical spine, but thoracic spine involvement is seen in 13% of cases [93]. It has been reported that SCIWORA was found in up to 38% of pediatric patients with myelopathy and no fracture or ligamentous injury on radiographs or CT [91].


Suspected Spine Trauma Child PCAs

Suspected Spine Trauma Child PCAs. In adults with SCIWORA, MRI screening did not yield positive findings in a substantial number of patients [98], but examinations in children were able to diagnose cord transection, contusion, and concussion in children <8 years of age with significant prognostic correlations [59]. In addition, children may have cartilaginous injuries that are not visualized on radiographs but are better detected with MRI [24]. It was shown that MRI facilitates the ability to classify thoracolumbar fractures in adults and children to aid in clinical decision making [27,28]. Adequate radiographs miss 35% of sacral fractures; therefore, CT and MRI are superior to radiography in the diagnosis of sacral fractures [29]. CTA Thoracic and Lumbar Spine CTA is not routinely used in the evaluation of children with thoracolumbar trauma. MRA Thoracic and Lumbar Spine MRA is not routinely used in the evaluation of children with thoracolumbar trauma. Arteriography Thoracic and Lumbar Spine Arteriography is not routinely used in the evaluation of children with thoracolumbar trauma. US Thoracic and Lumbar Spine Integrity of the posterior ligamentous complex plays an integral role for stability of the spine, and presence of posterior ligamentous complex injury may indicate more severe damage and change treatment interventions [88]. MRI is the modality of choice for evaluation of the posterior ligamentous complex, but it was shown that its sensitivity and specificity are lower than previously thought [89]. In a prospective study of 18 adult patients with acute thoracolumbar burst fractures, US was used to assess the posterior ligament complex and achieved a sensitivity of 99% and a specificity of 75% (P < . 05) when compared to operative results and preoperative radiographs, CT, and MRI [99]. CT Myelography Thoracic and Lumbar Spine CT myelography is rarely performed and has been largely replaced with MRI.


Suspected Spine Trauma Child PCAs

Suspected Spine Trauma Child PCAs. Exceptional indications may exist for patients with contraindications to MRI and in whom impending cord compression is suspected [90]. Summary of Recommendations Variant 1: Imaging is not recommended for the initial imaging of children 3 to 16 years of age with acute cervical spine trauma that meets low risk criteria (based on PECARN or NEXUS). Variant 2: Radiographs of the cervical spine are usually appropriate for the initial imaging of children 3 to 16 years of age with acute cervical spine trauma with at least one risk factor with reliable clinical examination (based on PECARN or NEXUS). The panel did not agree on recommending CT cervical spine without IV contrast or MRI cervical spine without IV contrast in children 3 to 16 years of age with this clinical condition. There is insufficient medical literature to conclude whether or not these patients would benefit from these procedures. CT cervical spine without IV contrast or MRI cervical spine without IV contrast as the initial imaging of children 3 to 16 years of age with acute cervical spine trauma and at least one risk factor with reliable clinical examination (based on PECARN or NEXUS) is controversial but may be appropriate. Variant 3: Radiographs of the cervical spine are usually appropriate for the initial imaging of children younger than 3 years of age with acute cervical spine trauma with a Pieretti-Vanmarcke weighted score greater than or equal to 2 to 8 points. The panel did not agree on recommending MRI cervical spine without IV contrast in children younger than 3 years of age with this clinical condition. There is insufficient medical literature to conclude whether or not these patients would benefit from these procedures. MRI cervical spine without IV contrast as the initial imaging of children younger than 3 years of age with acute cervical spine trauma with a Pieretti-Vanmarcke weighted score greater than or equal to 2 to 8 points is controversial but may be appropriate.


Suspected New Onset and Known Nonacute Heart Failure.  Introduction/Background Heart failure (HF) is a highly prevalent and complex clinical syndrome resulting from any structural or functional impairment of ventricular filling or ejection of blood [1]. HF may result from disorders of the pericardium, myocardium, valves, or great vessels as well as from certain systemic metabolic abnormalities [1]. While survival after the initial manifestation of HF has improved because of greater evidence-based treatment of risk factors and complications [6,7], the death rate remains high, with approximately 50% of HF cases dying within 5 years of initial diagnosis [7,8]. One in 9 deaths had HF mentioned on the death certificate, and HF was the underlying cause in over 60,000 deaths in 2013 [9]. There is significant financial impact associated with HF, which is likely to increase in coming decades. In 2012, the total expense related to HF nationally was estimated to be $30.7 billion, with 68% attributable to direct medical costs [4]. By 2030, the total annual expense of HF is projected to increase by almost 127% to $69.7 billion [4]. The American College of Radiology seeks and encourages collaboration with other organizations on the development of the ACR Appropriateness Criteria through society representation on expert panels. Participation by representatives from collaborating societies on the expert panel does not necessarily imply individual or society endorsement of the final document. Reprint requests to: publications@acr.org Suspected New-Onset and Known Nonacute Heart Failure HFrEF is typically found in the setting of a form of dilated cardiomyopathy, representing a large group of heterogeneous myocardial disorders characterized by ventricular dilation and depressed myocardial contractility in the absence of abnormal loading conditions (eg, hypertension or valvular disease) [1].


Suspected New Onset and Known Nonacute Heart Failure. In clinical practice and multicenter HF trials, the etiology of HF has often been categorized into either ischemic cardiomyopathy or nonischemic cardiomyopathy [1,14]. Thus, once a case of HFrEF has been identified, the basic distinction between an ischemic etiology and a nonischemic etiology with the support from imaging (see Variant 3) facilitates further diagnostic assessment and therapeutic planning, with guidance in further imaging provided by other reports on appropriate use of imaging [15]. Overview of Imaging Modalities Radiography Chest Information provided by chest radiography about: (1) noncardiovascular (eg, lung parenchymal disease) and cardiovascular (eg, cardiomegaly) anatomy of the chest [16]; (2) pulmonary vascular and edema patterns (eg, stages of pulmonary venous hypertension) [17]; and (3) vascular (eg, chronic coronary atherosclerosis) [18] and nonvascular (eg, calcified pericardial thickening) [19] calcification has potential applications to evaluation of the aforementioned HF variants. The appropriateness of the chest radiograph in the setting of suspicion of acute or potentially unstable chronic cardiopulmonary disease by history or physical examination has been previously established [20]. US Echocardiography Transthoracic Stress or Resting Echocardiography relies on ultrasonic waves to produce dynamic, usually tomographic versus volumetric images emphasizing a wide range of functional measures of cardiac chamber function and intravascular and intracavity flow in normal and various disease states, including HF, from which important hemodynamic measurements can be made in most patients noninvasively by transthoracic echocardiography (TTE) [21,22]. Despite its relatively weaker anatomic and histologic evaluation capabilities compared to some other cardiac imaging modalities, its risk-free nature, unless performed more invasively as transesophageal echocardiography (TEE), facilitates its use in the assessment of HF.


Suspected New Onset and Known Nonacute Heart Failure. SPECT or SPECT/CT MPI Rest and Stress Utilizing intravenously administered tracers, Single-photon emission computed tomography (SPECT) or SPECT/CT (ie, SPECT with CT attenuation correction) can provide insights into cardiac pathophysiology, including abnormalities of ventricular function (global and regional) and myocardial perfusion imaging (MPI) [23-25]. FDG-PET/CT Heart and Rb-82 PET/CT Heart Utilizing rubidium-82 (Rb-82), PET/CT is capable of reflecting myocardial physiology, including perfusion, wall motion, and cardiac flow reserve; this can be valuable in assessing HF [23-25]. Evaluation of myocardial viability can be performed utilizing fluorine-18-2-fluoro-2-deoxy-D-glucose (FDG) as the PET agent [23-25]. MRI Heart Cardiac MRI remains heavily reliant on electrocardiographic referencing of imaging data acquisition to the cardiac cycle and uses a magnetic field and radio waves to create detailed tomographic or volumetric images of high contrast. Depending upon the imaging acquisition employed and whether or not a gadolinium-based contrast agent was used and how and when administered relative to data acquisition, images demonstrating a range of abnormalities of (1) anatomy (eg, reduced thickness of ventricular wall, enlargement of atrial cavity, or increased thickness of pericardial sac); (2) histology (eg, myocardial edema, infiltration, deposition, or fibrosis); or (3) physiology (eg, depressed LVEF, restrictive transatrioventricular diastolic inflow, or reduced resting versus stress-induced myocardial strain or first-pass perfusion) [26-28]. These capabilities are potentially beneficial in assessing HF. Potential complications must be considered on a patient-by-patient basis before its use.


Suspected New Onset and Known Nonacute Heart Failure. CTA Coronary Arteries Referencing of image acquisition to the electrocardiographic recording facilitates high temporal and spatial resolution images of cardiovascular tissues that, when combined with intravenously administered iodinated contrast agents, permits primarily for the evaluation of coronary artery disease (CAD) as an etiology for newly diagnosed HF (coronary CT angiography [CTA]). Additionally, these advances can also be used for imaging during dynamic bolus contrast enhancement for the assessment of first-pass tissue perfusion (eg, myocardium) at rest or during pharmacologically induced stress, or the volumetric visualization of intraluminal/intracavity anatomy (eg, coronary artery, LV chamber) or arterial wall changes in static images (ie, CTA; or, without the use Suspected New-Onset and Known Nonacute Heart Failure of intravenous contrast for coronary calcification, calcium scoring for risk stratification). Delayed imaging helps further the detection of fibrous or fatty tissue replacement in cardiac structures (eg, LV wall) [26,29,30]. Despite marked improvements, prevailing concerns about potential complications are still limitations to the use of this modality. Arteriography Coronary Although a traditional gold standard for diagnosing disease of the coronary arteries or ventricles, conventional catheter-based selective coronary angiography is increasingly focused (eg, 38%) on patient-centric atherosclerotic CAD treatment planning or postrevascularization assessment [31]. It is supported by several complementary technologies allowing further characterization of plaque significance (eg, intravascular ultrasonography [US], fractional flow reserve) [32,33]. While concurrent LV ventriculography is dissuaded for LVEF determinations [34], direct hemodynamic measurements reflecting cardiac function maintain a distinct role in assessing a range of cardiovascular conditions in complicated clinical cases.


Suspected New Onset and Known Nonacute Heart Failure. Stress Examinations The objective of stress testing is typically to evaluate the extent and adequacy of the hyperemic response, thereby assessing the ability of the coronary circulation to augment flow to meet increasing work demand (ie, coronary flow reserve) [35]. When used in combination with imaging, depending on the degree and duration of induced ischemia, stress testing elicits and evaluates the ischemic endpoints that relate to coronary supply or demand imbalance characteristic of CAD. This ischemic cascade includes sequential abnormalities in the following order: perfusion, myocardial stiffening, wall motion abnormalities, electrocardiographic stress test segment changes, and chest pain. When appropriate, exercise-based stress testing is preferred to pharmacologically induced stress testing; unfortunately, it is impractical in many imaging environments, moreover for patients unable to adequately exercise [35]. Thus, the pharmacologic stress perfusion endpoint (achieved with a coronary artery dilating agent, such as adenosine or regadenoson) of induced coronary flow heterogeneity is used with the various forms of MPI; the functional ischemic endpoint (achieved with a myocardial inotropic agent, such as dobutamine) of induced wall motion abnormalities is detected and monitored during dynamic myocardial contraction imaging. Discussion of Procedures by Variant Prompt evidence-based diagnosis and treatment of new-onset nonacute HF may help decrease hospital stay, costs related to treatment, and mortality. Unfortunately, the accurate diagnosis of HF in the primary care setting is difficult and partly related to frequent suboptimal access to, and use of, cardiac imaging [36]. Variant 1: Suspected new-onset nonacute heart failure, not previously diagnosed. Initial imaging. Radiography Chest Historically, chest radiograph has been commonly used in the assessment of patients with suspected new-onset HF in the outpatient setting.


Suspected New Onset and Known Nonacute Heart Failure. Regardless of the acuity of new-onset HF, it is prudent to consider the impact of the training, experience, and focus of the chest radiography interpreter. For patients presenting to the emergency department (ED) with supportive clinical and laboratory evidence of HF, the accuracy in identifying HF on chest radiograph can vary from 78% for first-year emergency medicine residents, 85% for emergency medicine attendees, and 95% for radiologists [37]. A radiological score based on the sum of selected signs of congestion on chest radiograph correlates well with both findings on physical examination and lung impedance measurements during periods of sudden onset of HF [38]. Accordingly, in patients presenting to an ED with signs and symptoms of HF, those with sudden onset more likely demonstrate evidence of congestion on chest radiograph than those without sudden onset [39]. However, in ambulatory patients being evaluated in the community for suspected new-onset HF with standardized diagnostic evaluation, including chest radiography and TTE, a combination of 3 items from history plus 6 from physical examination have independent diagnostic value (c-statistic 0.83), increasing when supplemented by N- terminal pro-B-type natriuretic peptide (NT-proBNP) (c-statistic 0.86); chest radiography does not make a significant diagnostic contribution [40]. US Echocardiography Transthoracic Resting and Stress Evaluation of cardiac structure and function for newly suspected or potential HF, with rest-only echocardiography for the assessment of cardiac structure and function can be made accurately to guide therapy. Multicenter studies Suspected New-Onset and Known Nonacute Heart Failure


Suspected New Onset and Known Nonacute Heart Failure. Independent of and incremental to basic parameters (eg, LV mass, left atrial [LA] size, and mitral regurgitation) provided by TTE, the following insights can be gained from more advanced echocardiographic techniques in the setting of suddenly decompensated ventricular function: (1) need for HF hospitalization based on LV global longitudinal strain derived using speckle-tracking technology [51]; (2) risk of all-cause 1-year mortality based on Doppler-determined transmitral to mitral annular early diastolic velocity ratio reflecting LV filling pressure [52]; and (3) risk for in-hospital mortality, rehospitalization, and cardiovascular mortality by early mitral inflow velocity to early diastolic mitral annular velocity reflecting LV filling pressure estimated with Doppler [53]. Cardiac filling pressures can be estimated from physical examination with modest accuracy, and exposure to echocardiographic data may not significantly enhance accuracy beyond bedside examination alone, both for left- heart and right-heart pressures [54]. However, in ambulatory patients being evaluated in the community for suspected of nonacute new-onset HF using standardized diagnostic evaluation, TTE was shown to not make a significant diagnostic contribution [40]. Nuclear Medicine Ventriculography Radionuclide ventriculography (RNV) is an additional alternative that may be applied to the evaluation of cardiac function [41]. One of its benefits is its significant reproducibility, which has been used to track the efficacy of a variety of therapeutic interventions for patients with HF [41,55-57]. SPECT or SPECT/CT MPI Rest and Stress There is no evidence to support the use of rest and stress SPECT/CT MPI as an initial imaging modality for suspected new-onset nonacute HF. FDG-PET/CT Heart and Rb-82 PET/CT Heart There are only minimal data on the use of PET/CT for evaluation of newly suspected or potential HF [23-25].


Suspected New Onset and Known Nonacute Heart Failure. MRI Heart In addition to the evaluation of cardiac structure and function by rest-only MRI, myocardial perfusion, viability, and fibrosis imaging can assist in identification of etiology and assess prognosis [41,58]. There is no evidence to support the use of rest and stress MRI. CTA Coronary Arteries There is limited evidence to support the use of cardiac CTA as initial imaging for the evaluation of patients with newly suspected or potential HF. Arteriography Coronary The invasive nature of coronary angiography limits its use for the assessment of patients with newly suspected or potential HF. Suspected New-Onset and Known Nonacute Heart Failure is confounded by the following [1]: (1) in most symptomatic HF patients, variable balances of systolic and diastolic dysfunction coexist; and (2) derived LVEF values are dependent on the imaging modality used, method of analysis, and operator performance. Radiography Chest While radiography may play a role in diagnosing HF, there is no evidence to support the use of chest radiographs for differentiating HFrEF from HFpEF. US Echocardiography Transthoracic Resting and Stress At the time of presentation of patients to the ED with new-onset symptomatic HF, the differentiation between HFpEF and HFrEF using TTE has prognostic significance, with HFpEF having higher noncardiovascular mortality but lower cardiovascular mortality compared to HFrEF [62]. Beyond conventional 2-D TTE or TEE evaluations, the use of new more sensitive and more specific technologies, such as tissue Doppler imaging (TDI), strain rate, speckle tracking, or 3-D imaging, has facilitated the identification of other high-risk parameters associated with adverse outcomes, which are useful in guiding therapy and follow-up management of HFrEF patients [63].


Suspected New Onset and Known Nonacute Heart Failure. In outpatients with new-onset HF examined with TTE, including conventional Doppler and TDI, LA strain rate is significantly reduced in both HFrEF and HFpEF groups (without differences between them) compared with the non-HF group, with LA strain rate and indexed volume showing significant accuracy for HF diagnosis in receiver operating characteristic curves; however, LV strain rate shows no differences between non-HF and HFpEF groups, while both differed from the HFrEF group [64]. In patients with suddenly decompensated HF and presenting to the ED, point-of-care TTE has diagnostic sensitivity of 74% and specificity of 74% for HFrEF, changing to 36% and 100%, respectively, when combined with inferior vena cava collapsibility index and pleural sampling for B-lines; sensitivity and specificity of NT- proBNP >500 are 75% and 83%, respectively [65]. With the determination of HFrEF using TTE, LV filling pressure can be estimated well by LA expansion index, which predicts subsequent adverse events [66]. While early mitral inflow velocity to early diastolic mitral annular velocity on TTE with TDI is significantly higher in the elderly, compared to nonelderly, patients presenting with newly diagnosed suddenly decompensated HFrEF, there are no significant differences in in-hospital mortality, rehospitalization, and cardiovascular mortality during the following 45 months [53]. However, right ventricular (RV) systolic dysfunction, assessed using TTE with TDI of peak systolic velocity at the lateral tricuspid annulus, has prognostic significance in newly diagnosed HFrEF patients [67]. Diastolic dysfunction is widely considered a key pathophysiologic mediator of HFpEF. It is implicated as a major cause of shortness of breath on exertion in elderly primary-care patients who often are suffering from unrecognized HF (16%), more often from HFpEF (12%) than from either HFrEF (3%) or isolated right-sided HF (1%) as determined on TTE evaluation [68].


Suspected New Onset and Known Nonacute Heart Failure. In dyspneic patients presenting to an ED, a basic bedside TTE diastolic evaluation performed by an emergency physician-sonographer with limited diastology-specific training (3 hours of didactic and hands-on training by a cardiologist) can accurately identify clinically significant diastolic dysfunction, although correct grading of dysfunction may be only moderately accurate [69]. Several TTE parameters, including ratio of early mitral inflow velocity to TDI velocity at lateral mitral annulus, LA volume index, and the difference between duration of reversed pulmonary vein LA systole flow and duration of mitral A wave flow, have the greatest value in diagnosing HFpEF (sensitivity of 77% and specificity of 81%) [70]. However, for the initial diagnosis of HFpEF, the association of NT-proBNP measurement and TTE with TDI is superior to the use of either one alone [61]. Certainly, echocardiography technologies have provided greater understanding of the complex pathophysiology related to HFpEF. From the application of TTE with speckle tracking [71], it is now known that HFpEF patients (1) demonstrate significantly lower longitudinal and circumferential strains compared to both normal patients and hypertensive heart disease patients, indicating the presence of underlying impaired LV systolic function [72]; (2) have significantly lower myocardial systolic and diastolic LV performance compared to patients with asymptomatic LV diastolic dysfunction, and this combined dysfunction is associated with increased LV filling Suspected New-Onset and Known Nonacute Heart Failure


Suspected New Onset and Known Nonacute Heart Failure. pressures, decreased cardiac output, and worse New York Heart Association functional class [73]; (3) showing LV mechanical dyssynchrony have significantly higher rates of LV longitudinal systolic (64%) and diastolic (70%) dysfunction than those without dyssynchrony, suggesting that restoration of asynchronous contractions could improve systolic and diastolic longitudinal LV dysfunction, as well as associated symptoms [74]; (4) have significantly more impaired RV longitudinal diastolic (RV global longitudinal early-diastolic strain rate) and systolic (RV global longitudinal systolic strain) function than matched asymptomatic patients with LV diastolic dysfunction, suggesting that RV longitudinal systolic and diastolic dysfunction could contribute to symptoms [75]; and (5) demonstrate significantly reduced LA longitudinal systolic (LA late diastolic strain rate) and diastolic (LA systolic strain and strain rate) function compared to matched asymptomatic patients with LV diastolic dysfunction, suggesting that LA longitudinal systolic and diastolic dysfunction could be related to reduced functional capacity during effort [76]; accordingly, resting global peak LA longitudinal strain during LV systole has significant incremental diagnostic value over clinical and conventional TTE parameters (early diastolic mitral annular velocity ratio, LV mass index, and maximum LA volume index), and diagnostic value is further improved by adding leg-lifting during global peak LA longitudinal strain measurements (global chi-square = 72.2 versus 49.6; P < . 0001) [77]. Peak mitral annular systolic velocity on TEE with TDI is a significant independent predictor of HFpEF, and when used in combination with exercise, it may increase the diagnostic value of models using the variables recommended by the European Society of Cardiology guidelines [78].


Suspected New Onset and Known Nonacute Heart Failure. In addition, the assessment of longitudinal systolic and diastolic LV and RV function during a submaximal exercise stress TTE can confirm LV dysfunction related to HFpEF and might be used as a diagnostic test for difficult clinical situations [79]. In addition, it is known that within individual HFpEF cases, TTE with Doppler indexes of LV filling pressures (ie, early diastolic mitral annular velocity and E/Vp) do not reliably track directly measured filling pressures as these pressures vary, precluding the use of these techniques in the titration of medical therapy for HFpEF [80,81]. In HFpEF patients, global LV longitudinal strain measured using TTE with speckle tracking can help predict readmission within 30 days [51]. While global longitudinal strain is abnormal in HFpEF and is associated with a worse prognosis, it is not a powerful independent predictor of outcome [82]. However, exercise TTE may contribute to the identification of HFpEF patients, especially high-risk ones [83], and abnormal indices of LA mechanics, especially LA reservoir strain, are powerful clinical and prognostic factors in HFpEF [84]. Nuclear Medicine Ventriculography Because RNV can be performed to assess LVEF and volumes [41], it has potential in differentiating between HFrEF and HFpEF. SPECT or SPECT/CT MPI Rest and Stress While there is no evidence to support the use of rest and stress SPECT/CT specifically for differentiating between HFrEF and HFpEF, gated SPECT/CT has potential in differentiating between these forms of HF. FDG-PET/CT Heart and Rb-82 PET/CT Heart While there is no evidence to support the use of PET/CT specifically for differentiating between HFrEF and HFpEF, cardiac gated PET/CT has potential in differentiating between these forms of HF.


Suspected New Onset and Known Nonacute Heart Failure. MRI In addition to the evaluation of cardiac structure and function using rest-only MRI, myocardial focal fibrosis quantified by late gadolinium enhanced (LGE)-MRI in patients with HFpEF is an independent predictor of future events after the adjustment for prognostic factors (ie, age, diabetes mellitus, New York Heart Association classification, history of HF hospitalization, and LVEF) previously identified in the Irbesartan in Heart Failure with Preserved Ejection Fraction study [85]. CTA Coronary Arteries There is limited evidence to support the use of cardiac CTA for the differentiating patients with HFrEF from HFpEF. Arteriography Coronary While echocardiography is commonly used to diagnose and stage diastolic dysfunction, uncertainty in characterizing borderline cases may persist, and direct hemodynamic measurements may still be needed to establish a definitive diagnosis of HFpEF [86-88]. However, such invasive hemodynamic assessment is made without the need for concurrent coronary angiography or contrast LV ventriculography. Suspected New-Onset and Known Nonacute Heart Failure Variant 3: Confirmed new-onset heart failure with reduced ejection fraction of uncertain etiology: ischemic versus nonischemic. Because of reversible or irreversible ischemic injury to the LV myocardium, CAD with or without a history of antecedent myocardial infarction remains a major source of HFrEF nationally [1]. Prompt differentiation of ischemic HFrEF from nonischemic HFrEF is important because patients with ischemic cardiomyopathy can potentially have dramatic improvement with specific therapy, including revascularization [14,89]. Thus, in the setting of new-onset nonacute HFrEF, it is important to distinguish between ischemic and nonischemic (eg, remote diffuse myocarditis, alcoholic cardiomyopathy) etiologies in order to guide further evaluation and treatment [15].


Suspected New Onset and Known Nonacute Heart Failure. Radiography Chest While radiography may play a role in diagnosing HF, there is no evidence to support the use of chest radiography for differentiating ischemic versus nonischemic etiology of HF. US Echocardiography Transthoracic Resting and Stress Several studies have demonstrated the utility of stress echocardiography to identify both resting and poststress systolic wall motion abnormalities [90-92]. Additionally, these findings correlate to clinical outcomes. SPECT or SPECT/CT MPI Rest and Stress With SPECT/CT MPI, sensitivity and negative predictive value are both excellent for detecting CAD in patients with HF with either reduced or preserved LVEF; however, the distinction between ischemic and nonischemic etiologies is more characteristic of the evaluation of HFrEF [93,94]. In dyspneic patients with HFrEF without concomitant chest pain, the nonglobal resting LV dysfunction and high-summed stress MPI-deficiency score on gated rest and stress SPECT serve as independent predictors of an ischemic etiology; although low in sensitivity, specificity is acceptable [95]. While standard MPI (more often performed with SPECT than PET) is often deficient in making that distinction because a nonischemic cardiomyopathy can have focal defects in tracer uptake and CAD with global balanced ischemia can result in a normal-appearing perfusion pattern, new developments in measuring quantitative blood flow have potential to provide a more accurate determination of HFrEF etiology [94]. Nuclear Medicine Ventriculography RNV is used for the evaluation of cardiac function [41]. FDG-PET/CT Heart and Rb-82 PET/CT Heart An advantage of the use of stress MPI with PET is its improved accuracy for the detection of severe, multivessel CAD when compared to SPECT alone. Additionally, PET markers of absolute peak stress LVEF measurements and myocardial perfusion reserve may improve detection of patients with CAD [41,96,97].


Lung Cancer Screening PCAs

Lung Cancer Screening PCAs.  Introduction/Background Lung cancer remains the leading cause of cancer-related mortality for men and women in the United States [1]. Screening for lung cancer with annual low-dose CT (LDCT) is saving lives, and the continued implementation of lung cancer screening in clinical practice can save many more [2]. Since the publication of the National Lung Screening Trial (NLST) in 2011, which demonstrated a 20% reduction in lung cancer mortality with annual lung cancer screening [3], multiple clinical trials have demonstrated similar if not superior results [4-10]. Although there are known potential harms of lung cancer screening, including overdiagnosis and false positive results, the growing evidence has shown that correct implementation of lung cancer screening can provide substantial benefit at low clinical risk [2]. Retrospective analysis of the NLST data using updated standardized reporting specifically has been shown to substantially reduce false-positive rates of this screening test [11]. In 2015, the CMS began covering annual lung cancer screening for those who qualified based on the original United States Preventive Services Task Force (USPSTF) lung cancer screening criteria, which included patients 55 to 77 years of age with a 30 pack-year history of smoking, who were either currently using tobacco or who had smoked within the previous 15 years. In 2021, the USPSTF issued new screening guidelines, decreasing the age of eligibility to 50 years and pack years to 20 [12,13]. The recommendation was made following a systematic review of the lung cancer screening literature comprised of 223 publications that included 7 randomized clinical trials [14]. New guidelines are estimated to have doubled the population eligible for lung cancer screening in the United States and, importantly, will increase the number of women, underrepresented minorities, and those of lower socioeconomic status who qualify for this life-saving examination [15,16].


Lung Cancer Screening PCAs

Lung Cancer Screening PCAs. Although there has been some variation in eligibility for screening trials, studies have consistently excluded participants over 80 years of age. Special Imaging Considerations Acceptable low-dose lung cancer screening guidelines are available in the ACR-STR Practice Parameter for the Performance and Reporting of Lung Cancer Screening Thoracic Computed Tomography (CT) [17]. OR aVanderbilt University Medical Center, Nashville, Tennessee. bPanel Chair, Duke University, Durham, North Carolina. cCity of Hope National Medical Center, Duarte, California; Commission on Radiation Oncology. dMedical University of South Carolina, Charleston, South Carolina; Commission on Nuclear Medicine and Molecular Imaging. eEmory University Hospital, Atlanta, Georgia. fHampton VA Medical Center, Hampton, Virginia. gUniversity of Michigan Health System, Ann Arbor, Michigan. hUniversity of Wisconsin School of Medicine and Public Health, Madison, Wisconsin. iUniversity of Arizona College of Medicine, Phoenix, Arizona. jDivision of General Internal Medicine and Public Health, Vanderbilt University Medical Center, Nashville, Tennessee, Primary care physician. kMallinckrodt Institute of Radiology, Saint Louis, Missouri. lMedical University of South Carolina, Charleston, South Carolina; American College of Chest Physicians. mNational Institutes of Health, Bethesda, Maryland. nDuke University School of Medicine, Durham, North Carolina; The Society of Thoracic Surgeons. oBoston University School of Medicine and Center for Healthcare Organization & Implementation Research, VA Boston Healthcare System, Boston, Massachusetts; American College of Chest Physicians. pUniversity of California San Francisco, San Francisco, California; American Geriatrics Society. qSpecialty Chair, Ohio State University Wexner Medical Center, Columbus, Ohio.


Lung Cancer Screening PCAs

Lung Cancer Screening PCAs. The American College of Radiology seeks and encourages collaboration with other organizations on the development of the ACR Appropriateness Criteria through representation of such organizations on expert panels. Participation on the expert panel does not necessarily imply endorsement of the final document by individual contributors or their respective organization. Reprint requests to: publications@acr.org Lung Cancer Screening Discussion of Procedures by Variant Variant 1: Lung cancer screening. Patient 50 to 80 years of age and 20 or more packs per year smoking history and currently smoke or have quit within the past 15 years. Initial imaging. CT Chest With IV Contrast There is no relevant literature regarding the use of CT with intravenous (IV) contrast for lung cancer screening. CT Chest Without and With IV Contrast There is no relevant literature regarding the use of CT without and with IV contrast for lung cancer screening. CT Chest Without IV Contrast Screening The population described in this variant exactly matches the updated USPSTF eligibility guidelines for lung cancer screening [12]. These guidelines were expanded from the original eligibility criteria studied in the NLST. The NLST enrolled 53,454 participants 55 to 74 years of age with a 30 pack-year history of smoking, who were either currently using tobacco or had tobacco use in the previous 15 years. This randomized controlled study demonstrated a 20% reduction lung cancer mortality with annual CT imaging [3]. Screening for lung cancer at an earlier age and with less tobacco exposure than suggested with the original guidelines may help to improve racial and gender disparities in lung cancer screening eligibility [15]. In fact, the original guidelines may have exacerbated disparities in lung cancer morbidity and mortality for women, underrepresented minorities, and vulnerable patients of low socioeconomic status [22-24].


Lung Cancer Screening PCAs

Lung Cancer Screening PCAs. A retrospective examination of lung cancer incidence among the predominantly Black population in the Southern Community Cohort Study demonstrated a much smaller percentage of Black patients with lung cancer met screening eligibility criteria (32%) compared with White patients (56%). The lower percentage of eligibility was primarily associated with lower pack years [25]. Additionally, the expansion of lung cancer screening guidelines will improve eligibility of women for lung cancer screening compared with men [15]. FDG-PET/CT Skull Base to Mid-Thigh The role of fluorine-18-2-fluoro-2-deoxy-D-glucose (FDG)-PET/CT skull base to mid-thigh as a lung cancer screening modality has not been adequately studied. The body of evidence for this modality is growing but remains limited [26,27]. MRI Chest Without and With IV Contrast The role of MRI, chest without or with IV contrast, as a lung cancer screening modality has not been adequately studied. MRI Chest Without IV Contrast The role of MRI chest without IV contrast as a lung cancer screening modality has not been adequately studied. There is a growing body of evidence suggesting MRI without IV contrast may have a role in screening for lung cancer [28-30]. Radiography Chest Chest radiography screening does not reduce lung cancer mortality in this population [3]. Lung Cancer Screening Variant 2: Lung cancer screening. Patient younger than 50 years of age and 20 or more packs per year history of smoking and one additional risk factor (ie, radon exposure or occupational exposure or cancer history or family history of lung cancer or history of COPD or history of pulmonary fibrosis). Initial imaging. CT Chest With IV Contrast There is no evidence to support screening in this population with chest CT with IV contrast. CT Chest Without and With IV Contrast There is no evidence to support screening in this population with chest CT without and with IV contrast.


Lung Cancer Screening PCAs

Lung Cancer Screening PCAs. CT Chest Without IV Contrast Screening Smoking is the leading cause of lung cancer, accounting for approximately 90% of lung cancer cases in the United States [12]. Increased age is also associated with an increased risk for lung cancer, with most patients diagnosed after age 50 [1]. Currently screening for lung cancer is not recommended for those <50 years of age. Additional data are needed to determine if screening younger patients with additional risk factors such as radon exposure, occupational exposure, cancer history, family history of lung cancer, chronic obstructive pulmonary disease (COPD), or emphysema is of appropriate benefit. These criteria have been included in previous evaluation of eligibility in multiple models and in the National Comprehensive Cancer Network Guidelines (High-Risk Group 2) [31]. Patients with a history of cancer are at increased risk for developing a second primary cancer, and the most common second primary cancer is lung cancer. Within the NLST, 1,071 study participants had a prior history of cancer. These patients were found to have a higher age-adjusted cancer-detection rate on baseline LDCT than those without a cancer history [32]. A retrospective study within a clinical lung cancer screening program has shown that those eligible for screening with a previous cancer history have a higher risk for cancer than those without a cancer history who are screening eligible [33]. A retrospective cohort study of 276 patients with a history of hepato-gastrointestinal cancer and second primary lung cancer suggests that screening for lung cancer in this patient population may improve mortality [34]. Although these results suggest a possible benefit for screening for lung cancer in those with a history of cancer, this is not recommended for cancer survivors without tobacco exposure of at least 20 pack years. A real-world cohort study in China evaluated 15,996 participants with LDCT and found 142 cases of lung cancer.