Acute Pyelonephritis

Acute Pyelonephritis. History of renal stones or renal obstruction. Initial imaging. CT Abdomen and Pelvis Renal stones or renal obstruction can be a source of APN [1,8,11,15,18,19]. CT of the abdomen and pelvis is highly sensitive for detection of stones and hydronephrosis [8,11]. Furthermore, CT is a useful imaging study to diagnose APN if symptoms persist or worsen after 72 hours have passed [1,8,14-21]. CT imaging should include the pelvis to identify stones in the distal ureters or urinary bladder, congenital abnormalities of the distal ureters, and abnormalities of the urinary bladder, among other potential sources of APN. Both unenhanced and contrast-enhanced CT are able to detect urolithiasis, perinephric fluid, renal swelling, and hydronephrosis [1,8,14,17-19]. However, contrast-e nhanced CT has been shown to improve detection of APN parenchymal changes, a renal abscess, and extrarenal acute conditions that may clinical present as suspicious for APN [19]. Of note, unenhanced CT has higher sensitivity than contrast-enhanced CT for detection of small renal calculi. Acute Pyelonephritis In a prospective nonrandomized data collection study of patients with a final diagnosis of APN (n = 827), the detection rate of APN was 84.4% (445/527) by abdominal CT and only 40% (72/180) by abdominal US [10]. Although the detection rate of urolithiasis and hydronephrosis were similar by abdominal CT and abdominal US, the rate of detection of renal abscess was 4.0% (21/527) by abdominal CT and only 1.1% (2/180) by US [10]. CT and US have similar detection rates for renal stones and hydronephrosis. Advantages of abdominal CT and US over abdominal MRI may include superior detection of small urothelial stones [1,14,15,18]. In a small retrospective study of adult patients with clinical and laboratory suspicion of APN who all underwent triphasic abdominal CT (n = 100), the accuracy of the nephrographic phase among 2 readers for diagnosis of APN was 90% to 92% and for diagnosis of urolithiasis was 96% to 99% [22].


Acute Pyelonephritis

Acute Pyelonephritis. There was no significant difference in the accuracy of the triphasic abdominal CT relative to nephrographic phase alone [22]. Thereby, detection of urothelial stones is similar with unenhanced and contrast-enhanced CT. CT Abdomen CT of the abdomen without IV contrast has high accuracy for detection or renal stones, and CT of the abdomen with IV contrast has high accuracy for the diagnosis of APN. However, CT of the abdomen alone does not allow for a comprehensive assessment of the entire genitourinary tract [1,8,14-21]. CT imaging should include the pelvis to detect potential pelvic abnormalities including urolithiasis in the distal ureters or urinary bladder, congenital abnormalities of the distal ureters and abnormal insertion sites, and abnormalities of the urinary bladder, among other potential sources of APN. CTU CTU There is insufficient evidence to support the use of CTU for detection of suspected APN in the complicated patient. There is variability in the CTU imaging technique. The added benefit of an excretory phase from any CTU image acquisition protocol is likely negligible with respect to detection and characterization of APN in a complicated patient. DMSA Renal Scan CT may have higher accuracy than DMSA renal scintigraphy for detection of APN and certainly has higher accuracy for detection of stones, which cannot be directly visualized by renal scintigraphy [24]. Fluoroscopy Antegrade Pyelography Antegrade pyelography is not beneficial in the imaging evaluation for suspected APN in a patient with a history of renal stones or renal obstruction [15]. Fluoroscopy Voiding Cystourethrography VCUG is not beneficial in the imaging evaluation for suspected APN in a patient with a history of renal stones or renal obstruction [15].


Acute Pyelonephritis

Acute Pyelonephritis. MRI Abdomen and Pelvis MRI of the abdomen and pelvis can be useful for detecting APN, scarring, congenital anomalies of the kidneys, renal abscesses, hydronephrosis, and pyonephrosis [28-30], and imaging of the pelvis could improve detection of stones in the distal ureters or urinary bladder, congenital abnormalities of the distal ureters, and abnormalities of the urinary bladder, among other potential sources of APN. However, MRI has poor accuracy for the detection of small urothelial calculi [31,32]. Other disadvantages of MRI includes its relatively reduced ability to detect gas in emphysematous pyelonephritis [31,32]. Similar to CT, MRI is not beneficial early in uncomplicated cases [8,14]. MRI Abdomen MRI of the abdomen has high accuracy for the diagnosis of APN in a complicated patient but does not allow for a comprehensive assessment of the entire genitourinary tract. Failure to include the pelvis could lead to a missed opportunity to detect urolithiasis in the distal ureters or urinary bladder, congenital abnormalities of the distal ureters and abnormal ureteral insertion sites, and abnormalities of the urinary bladder, among other potential sources of APN. MRI has poor accuracy for the detection of small urothelial calculi. Another disadvantage of MRI includes its relatively reduced ability to detect gas in emphysematous pyelonephritis [31,32]. MRU The excretory phase of MRU does not confer additional benefit with respect to detection and characterization of APN in a complicated patient. Furthermore, MRU has poor accuracy for the detection of small urothelial calculi Acute Pyelonephritis [31,32]. In a small prospective study comparing CTU with MRU in adult patients referred from the emergency department for evaluation of renal colic or hematuria (n = 70), all cases of urinary stones were detected by CTU (100%) versus 79% of cases detected by MRU [43]. Another disadvantage of MRU includes its relatively reduced ability to detect gas in emphysematous pyelonephritis [31,32].


Acute Pyelonephritis

Acute Pyelonephritis. Radiography Abdomen and Pelvis Radiography of the abdomen and pelvis (KUB) has limited utility in the imaging evaluation for suspected APN in a patient with a history of renal stones or renal obstruction [15]. Although radiography of the abdomen and pelvis could detect large calculi, it cannot detect APN. Radiography Intravenous Urography IVU is not beneficial in the imaging evaluation for suspected APN in a patient with a history of renal stones or renal obstruction [15]. US Abdomen US of the kidneys has nearly 100% sensitivity for detection of large stones (>5 mm) and hydronephrosis, although the accuracy for detection of small stones (<3 mm) is poor [44,45]. Some disadvantages of US compared with CT are a lower rate of detection of APN and renal abscess [10,36-38]. Of note, the sensitivity for detection of acute complicated pyelonephritis and for detection of a renal abscess is higher with contrast-enhanced US relative to unenhanced US [37,38]. In one small retrospective study of adults with APN (n = 100), the accuracy of contrast-enhanced US for detection o f APN approached that of contrast- enhanced CT [39]. US Color Doppler Kidneys and Bladder Retroperitoneal US of the kidneys has nearly 100% sensitivity for detection of large stones (>5 mm) and hydronephrosis, although the accuracy for detection of small stones (<3 mm) is poor [44,45]. Use of color Doppler has been shown to increase sensitivity for detection of APN in adults and children [40-42]. Inclusion of the bladder could identify other abnormalities contributing to APN. A disadvantage of US compared with CT is a lower rate of detection of APN and renal abscess [10,36-38]. Variant 4: Suspected acute pyelonephritis. Pregnant patient with no other complications (eg, no history of diabetes, immune compromise, history of stones or renal obstruction, prior renal surgery, vesicoureteral reflux, or lack of response to therapy). Initial imaging.


Acute Pyelonephritis

Acute Pyelonephritis. CT Abdomen and Pelvis There is no current literature specific to the use of CT of the abdomen and pelvis in the evaluation of suspected APN in pregnant patients. CT imaging of the abdomen and pelvis is not supported as the initial imaging in pregnant patients. The main disadvantage of using CT of the abdomen and pelvis in a pregnant patient is the risk of ionizing radiation to the embryo or fetus and the mother, particularly for the pelvic portion of the examination [46]. CT Abdomen There is no current literature to support the use of CT of the abdomen in the evaluation of suspected APN in pregnant patients. CT imaging of the abdomen does not allow for detection of pelvic abnormalities including urolithiasis in the distal ureters or urinary bladder, congenital abnormalities of the distal ureters and abnormal insertion sites, and abnormalities of the urinary bladder, among other potential sources of APN. CTU CTU There is no current literature to support the use of CTU in the evaluation of suspected APN in pregnant patients. There is variability in CTU imaging technique. The added benefit of an excretory phase from any CTU image acquisition protocol is likely negligible with respect to the detection and characterization of APN in a pregnant patient. A CTU protocol that does not include unenhanced imaging and that uses a split bolus to achieve a mixed nephrographic and excretory phase could mask the presence of urolithiasis. DMSA Renal Scan DMSA renal scintigraphy is not beneficial in the imaging evaluation for suspected APN in a pregnant patient [15]. Fluoroscopy Antegrade Pyelography Antegrade pyelography is not beneficial in the imaging evaluation for suspected APN in a pregnant patient [15]. Acute Pyelonephritis Fluoroscopy Voiding Cystourethrography VCUG is not beneficial in the imaging evaluation for suspected APN in a pregnant patient [15].


Acute Pyelonephritis

Acute Pyelonephritis. MRI Abdomen and Pelvis There is no current literature specific to the use of MRI of the abdomen and pelvis in the evaluation of suspected APN in pregnant patients. MRI of the abdomen and pelvis is generally safe in pregnant patients and may be useful in certain situations. MRI does do not expose the embryo, or fetus, or pregnant mother to ionizing radiation and can be useful for detecting APN, scarring, congenital anomalies of the kidneys, renal abscesses, hydronephrosis, and pyonephrosis [28-30]. Although there are no known adverse effects to human fetuses and no known cases of nephrogenic systemic fibrosis linked to the use of clinical doses of gadolinium-based contrast agents (GBCAs) in pregnant patients, GBCAs should only be used if the indication is considered critical and the potential benefits justify the potential unknown risk to the fetus [47]. MRI of the abdomen can be useful for detecting APN, scarring, congenital anomalies of the kidneys, renal abscesses, hydronephrosis, and pyonephrosis [28-30]. DWI [20] and contrast-enhanced MRI have similar benefits in detecting renal abnormalities [27] . Stud ies in adults have shown that DWI can be useful in the diagnosis of pyelonephritis [28-30]. APN, renal abscesses, and pyonephrosis have lower ADC values than normal renal cortical parenchyma [28]. Inclusion of the pelvis could improve detection of abnormalities of the lower urinary tract. MRI may allow for a limited evaluation of the embryo or fetus. However, traditional MRI examinations do n ot provide a comprehensive assessment of the urinary collecting systems [8,31,32]. The main disadvantages of MRI are poor accuracy for the detection of small urothelial calculi and reduced accuracy for detection of emphysematous pyelonephritis, [31,32]. MRI Abdomen There is no current literature specific to the use of MRI of the abdomen in the evaluation of suspected APN in pregnant patients.


Acute Pyelonephritis

Acute Pyelonephritis. MRI of the abdomen does not allow for detection of pelvic abnormalities including urolithiasis in the distal ureters or urinary bladder, congenital abnormalities of the distal ureters and abnormal insertion sites, and abnormalities of the urinary bladder, among other potential sources of APN. MRI of the abdomen is generally safe in pregnant patients and may be useful in certain situations [28-30]. Although there are no known adverse effects to human fetuses and no known cases of nephrogenic systemic fibrosis linked to the use of clinical doses of GBCAs in pregnant patients, GBCAs should only be used if the indication is considered critical and the potential benefits justify the potential unknown risk to the fetus [47]. MRI of the abdomen may allow for a limited evaluation of the embryo or fetus, although most fetuses would not be included in the field of view. The main disadvantages of MRI are poor accuracy for the detection of small urothelial calculi and reduced accuracy for detection of emphysematous pyelonephritis [31,32]. MRU There is no current literature specific to the use of MRU without IV contrast in the evaluation of suspected APN in pregnant patients. The excretory phase of MRU does not confer additional benefit with respect to detection and characterization of APN in a pregnant patient. Radiography Abdomen and Pelvis Radiography of the abdomen and pelvis is not beneficial in the imaging evaluation for suspected APN in a pregnant patient [15]. Radiography Intravenous Urography IVU is not beneficial in the imaging evaluation for suspected APN in a pregnant patient [15]. US Abdomen There is no current literature specific to the use of US of the abdomen in the evaluation of suspected APN in pregnant patients. Pregnancy increases the risk of complications from APN, although poor obstetrical outcomes are rare [48]. US of the abdomen may be used to detect complications of APN.


Acute Pyelonephritis

Acute Pyelonephritis. US of the abdomen is safe in pregnancy and is rapid and portable and does not require the use of contrast material [8]. US is often used as a screening examination in pregnancy, is sensitive and specific test for diagnosing hydronephrosis, and does not expose the patient or fetus to ionizing radiation [49,50]. Acute Pyelonephritis Physiologic hydronephrosis of pregnancy occurs in >80% of pregnant patients in the second and third trimester; therefore, hydronephrosis alone is not a reliable sign of APN in pregnant patients [51]. Furthermore, US has a low detection rate of APN and renal abscess [10,36-38]. US Color Doppler Kidneys and Bladder Retroperitoneal There is no current literature specific to the use of US color Doppler of the kidneys, bladder, and retroperitoneum in the evaluation of suspected APN in pregnant patients. US of the kidney, ureters, and bladder is safe in pregnancy, is rapid and portable, and does not require the use of contrast material [8]. US is often used as a screening examination in pregnancy, is sensitive and specific test for diagnosing hydronephrosis, and does not expose the patient or fetus to ionizing radiation [49,50]. Use of color Doppler has been shown to increase sensitivity for detection of APN compared to US with grayscale imaging [40-42]. Physiologic hydronephrosis of pregnancy occurs in >80% of pregnant patients in the second and third trimester; therefore, hydronephrosis alone is not a reliable sign of APN in pregnant patients [51]. Furthermore, US has a lower detection rate of APN and renal abscess than CT [10,36-38]. Variant 5: Suspected acute pyelonephritis. History of pelvic renal transplant with native kidneys in situ and no other complications (eg, no history of pyelonephritis, diabetes, history of stones or renal obstruction, prior renal surgery, advanced age, vesicoureteral reflux, lack of response to therapy, or pregnancy). Initial imaging. Some local practice patterns do not routinely give IV contrast agents to patients with renal transplants.


Acute Pyelonephritis

Acute Pyelonephritis. For this variant, we assumed there are no contraindications to IV contrast agents. CT Abdomen and Pelvis There is no current literature specific to the use of CT of the abdomen and pelvis in the evaluation of suspected APN in a patient with a pelvic renal transplant and native kidneys in situ. CT of the abdomen and pelvis would include imaging of the native and transplant kidneys, and CT with IV contrast is highly accurate for the diagnose APN in a complicated patient, particularly if symptoms persist or worsen after 72 hours have passed [1,8,14-21]. Both unenhanced and contrast-enhanced CT are able to detect urolithiasis, perinephric fluid, renal swelling, and hydronephrosis [1,8,14,17-19]. Contrast-enhanced CT has been shown to improve detection of APN parenchymal changes, a renal abscess, and extrarenal acute conditions that may clinically present as suspicious for APN. CT imaging of the pelvis can detect potential pelvic abnormalities including urolithiasis in the distal ureters or urinary bladder, congenital abnormalities of the distal ureters and abnormal insertion sites, and abnormalities of the urinary bladder, among other potential sources of APN. Of note, unenhanced CT has higher sensitivity than contrast- enhanced CT for detection of small renal calculi. CT Abdomen There is no current literature to support the use of CT of the abdomen in the evaluation of suspected APN in a patient with a pelvic renal transplant and native kidneys in situ. APN of a renal allograft is more common than APN of the native kidneys, and renal transplant recipients are at high risk for complications from a variety of factors, including immunosuppression [52]. CT of the abdomen would not include complete imaging of the pelvic transplant kidney(s), which might miss important pathology in the transplant kidney [1,8,14-21]. CTU CTU There is limited information on the benefit of CTU for detection of suspected APN in a patient with a pelvic renal transplant and native kidneys in situ.


Acute Pyelonephritis

Acute Pyelonephritis. The added benefit of an excretory phase from any CTU image acquisition protocol is likely negligible with respect to detection and characterization of APN in this patient cohort. DMSA Renal Scan DMSA renal scintigraphy is not beneficial in the imaging evaluation for suspected APN in a patient with a pelvic renal transplant and native kidneys in situ [15]. Fluoroscopy Antegrade Pyelography Antegrade pyelography is not beneficial in the imaging evaluation for suspected APN in a patient with a pelvic renal transplant and native kidneys in situ [15]. Fluoroscopy Voiding Cystourethrography VCUG is not beneficial in the imaging evaluation for suspected APN in a patient with a pelvic renal transplant and native kidneys in situ [15]. Acute Pyelonephritis MRI Abdomen and Pelvis There is limited literature on the use of MRI of the abdomen and pelvis in the evaluation of suspected APN in a patient with a pelvic renal transplant and native kidneys in situ. APN is rare in native kidneys. However, APN of a renal allograft is more common, and renal transplant recipients are at high risk for complications from a variety of factors, including immunosuppression [52]. In a p rospective study of renal transplant recipients with suspected APN (n = 5 6), contrast-enhanced MRI was positive in 66% (37/56) of patients [53] . In a small retrospective study of 24 kidney transplant recipients who underwent MRI without IV contrast and had clinical suspicion of APN, 9 2% (22/24) of patients had positive findings on MRI, specifically on DWI and ADC images [54]. Studies in ad ult patients without renal transplants hav e shown that DWI can be useful in the diagnosis of uncomplicated pyelonephritis [28-30]. APN, renal abscesses, and pyonephrosis have lower ADC values than normal renal cortical parenchyma [28]. As such, DWI and ADC provide a viable alternative to contrast-enhanced MRI or CT [30].


Acute Pyelonephritis

Acute Pyelonephritis. The main disadvantages of MRI of the abdomen and pelvis are poor accuracy for the detection of small urothelial calculi and reduced accuracy for detection of emphysematous pyelonephritis, [31,32]. MRI Abdomen There is limited literature on the use of MRI of the abdomen in the evaluation of suspected APN in a patient with a pelvic renal transplant and native kidneys in situ. APN is rare in native kidneys, and abdominal imaging would not include complete imaging of the pelvic transplant kidney(s), which would likely miss important pathology in the transplant kidney [1,8,14-21]. MRI Pelvis There is limited literature on the use of MRI of the pelvis in the evaluation of suspected APN in a patient with a pelvic renal transplant and native kidneys in situ. Pelvic MRI alone would not include evaluation of the native kidneys. MRI of the abdomen and pelvis would be more comprehensive for identification of the source of the APN. MRU There is no current literature specific to the use of MRU in the evaluation of suspected APN in patients with a pelvic renal transplant and native kidneys in situ. The excretory phase of MRU does not confer additional benefit with respect to detection and characterization of APN in a pregnant patient. Radiography Abdomen and Pelvis Radiography of the abdomen and pelvis is not beneficial in the imaging evaluation for suspected APN in a patient with a pelvic renal transplant and native kidneys in situ [15]. Radiography Intravenous Urography IVU is not beneficial in the imaging evaluation for suspected APN in a patient with a pelvic renal transplant and native kidneys in situ [15]. US Abdomen APN is rare in native kidneys. Because an US of the abdomen would not include complete imaging of the pelvic transplant kidney(s), the examination is not likely to diagnose APN [1,8,14-21]. US Color Doppler Kidneys and Bladder Retroperitoneal APN is most commonly an issue with the transplant kidney.


Blunt Chest Trauma Suspected Cardiac Injury.  aUniversity of Michigan Health System, Ann Arbor, Michigan. bPanel Chair, Duke University Medical Center, Durham, North Carolina. cPanel Chair, University of Chicago, Chicago, Illinois. dPanel Vice-Chair, Massachusetts General Hospital, Boston, Massachusetts. ePanel Vice-Chair, University of Kansas Medical Center, Kansas City, Kansas. fUniversity of Louisville School of Medicine, Louisville, Kentucky. gStanford University Medical Center, Stanford, California; The Society of Thoracic Surgeons. hUniversity of Southern California, Los Angeles, California. iThe University of Chicago Medical Center, Chicago, Illinois; American College of Physicians. jKaiser Permanente, Los Angeles, California. kVancouver General Hospital, Vancouver, British Columbia, Canada. lUniversity of Washington, Seattle, Washington. mUniversity of California San Diego, San Diego, California. nHarvard Medical School, Boston, Massachusetts. oNaval Medical Center Portsmouth, Portsmouth, Virginia. pMassachusetts General Hospital, Boston, Massachusetts. qStritch School of Medicine Loyola University Chicago, Maywood, Illinois; Society for Cardiovascular Magnetic Resonance. rDuke University School of Medicine, Durham, North Carolina; The Society of Thoracic Surgeons. sUniversity of Virginia Health Center, Charlottesville, Virginia; Society of Cardiovascular Computed Tomography. tWisconsin Heart Hospital, Milwaukee, Wisconsin; Nuclear cardiology expert. uDenver Health MC/UPI, Denver, Colorado; American College of Emergency Physicians. vSpecialty Chair, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin. wSpecialty 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 society representation on expert panels.


Blunt Chest Trauma Suspected Cardiac Injury. 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 All elements are essential: 1) timing, 2) reconstructions/reformats, and 3) 3-D renderings. Standard CTs with contrast also include timing issues and recons/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. CTA can also be performed with or without ECG gating. The ECG gating is usually prospective and allows for better assessment of cardiac injuries as well as concomitant aortic injuries in patients with blunt chest trauma and concomitant cardiac injuries. The role of focused assessment with sonography for trauma (FAST) (or extended-FAST or chest abdominal-FAST in evaluating chest injury) is primarily one of triage; a positive FAST and signs of hemodynamic instability may lead to immediate surgical intervention rather than CT [14,15]. Ultrasound (US) may be able to diagnose certain thoracic and abdominal injuries, but it is an insufficient test to fully exclude injuries to these areas because it has a relatively lower specificity compared with CT [16]. Hemodynamic instability and findings such as abnormal ECG and increased level of high-sensitivity troponin in hemodynamically stable patients should raise the suspicion of cardiac injuries, and these patients should undergo rapid cardiac assessment by echocardiography [7,10]. An initial FAST examination can detect pericardial effusion and wall motion abnormality. Hall et al [11] analyzed the cardiac component of the FAST examination in hypotensive (systolic blood pressure <90 mm Hg) and normotensive trauma patients.


Blunt Chest Trauma Suspected Cardiac Injury. The authors concluded that performing echocardiography in hypotensive blunt trauma patients is effective in evaluating myocardial rupture with limited evaluation of the right ventricle, valvular injuries such as valvular or perivalvular regurgitation, hemopericardium, tamponade, pneumopericardium, and myocardial infarction. The authors have also stressed that a cardiac FAST examination may not be an effective use of resources for normotensive blunt trauma patients. In general, hemodynamically stable patients should be either monitored or evaluated by cardiac imaging if the abnormal ECG findings persist or cardiac troponin levels are rising [7]. Patients with normal ECG and cardiac troponin levels are usually considered low probability for cardiac blunt trauma and therefore can be safely discharged [7,18,19]. CT chest has been accepted as an imaging modality of choice in patients with blunt chest trauma [20-23]. The superior spatial resolution combined with the ability of contrast enhancement to display the anatomic structures and 3-D reconstructions allows for accurate assessment of cardiovascular anatomy and the associated detection of pathology. Ideally, CT chest in patients with suspected cardiac injuries as part of the blunt trauma evaluation should be performed with intravenous (IV) contrast. However, in some instances, CT chest could be performed either without or with and without IV contrast, as described in the CT chest sections below. CT Chest Without IV Contrast In patients with suspected cardiac injury, CT chest studies without IV contrast can easily identify hemothorax or hemopericardium from pleural and pericardial effusion by measuring the attenuation within the pleural or pericardial space. CT chest without IV contrast can also accurately detect sternal fractures by evaluating the sagittal and 3-D reconstructions.


Blunt Chest Trauma Suspected Cardiac Injury. Even though a sternal fracture in the setting of trauma is considered a benign condition, myocardial contusion and myocardial concussion leading to malignant ventricular arrhythmias can be encountered with this finding only if there are ECG changes and cardiac troponin levels are rising. It is difficult to predict which patients with a sternal fracture will develop cardiac complications. In a cohort of 54 patients with a suspected sternal fracture by emergency physicians in a multicenter descriptive retrospective study, only 72% of the patients had ECG performed at baseline, 33% had follow-up ECG, and 30% had troponin I assessment; in this group, 6% of the patients were diagnosed with arrhythmias and myocardial contusion. The authors also showed that only 38 (70%) of the patients with suspected sternal fractures were confirmed by imaging [24]. This study shows the importance of diagnosing sternal fractures in conjunction with ECG monitoring and troponin assessment to evaluate cardiac Blunt Chest Trauma-Suspected Cardiac Injury injury in the setting of blunt trauma. However, it is noteworthy that echocardiography is not recommended in isolated sternal fractures in the presence of a normal ECG and cardiac troponins to evaluate for myocardial contusion [25]. The use of CT chest without IV contrast is of paramount importance in patients with prior chest surgery or retained metal fragments for accurate diagnosis of cardiac trauma and concomitant vascular injuries. CT Chest Without and With IV Contrast CT chest with and without IV contrast is the most effective routine imaging modality for detecting thoracic injuries caused by blunt trauma. It accurately detects hemorrhage within the chest followed by identification of concomitant cardiovascular injuries as a source of bleeding.


Blunt Chest Trauma Suspected Cardiac Injury. CT Heart Function and Morphology ECG-gated cardiac CT with IV contrast can be used in the trauma setting to evaluate the cardiac structure and can detect cardiac chamber rupture and pericardial rupture [35]. A case report has described various entities such as rupture of the right ventricle with contained contrast extravasation [36], left atrial appendage tear, rupture of the atria at the junction with pulmonary veins, and inferior vena cava. The existing literature focuses on clinical decision scores along with a chest radiograph, ECG, and troponin assessment [37] as a screening algorithm to triage patients in whom cardiac CT has the potential to guide life-saving interventions. Cardiac CT has been demonstrated to be highly accurate for the detection of cardiac structural abnormalities in the nontrauma setting. A case report described the right ventricular pseudoaneurysm following an MVA diagnosed with cardiac CT and missed with echocardiography [36]. Another case report described contrast extravasation from the apical portion of the right ventricle into the pericardial space compatible with contained ventricular rupture in addition to multiple chest injuries detected at CT [38]. Other case reports have described the ability of contrast-enhanced CT chest to detect enhancement defects in the myocardium suggestive of myocardial infarction in the setting of trauma. These findings triggered further imaging and subsequent intervention [21] to treat coronary artery dissection following blunt trauma [39]. In addition, another case report described a patient with a hemothorax caused by a left atrial appendage rupture, pleuropericardial tear, and cardiac herniation through the pericardium [40]. Moreover, case reports have described the ability of CT chest with IV contrast to detect enhancement defect in the myocardium suggestive of myocardial infarction and ventricular septal defect in the setting of trauma that triggered further imaging and intervention [6,21,41].


Blunt Chest Trauma Suspected Cardiac Injury. CTA Chest Although this document excludes the discussion of vascular injuries, CTA chest without and with IV contrast is useful in a patient with blunt chest trauma and suspected cardiac injury. This is because CT chest can identify the extent of cardiac injury as well as other concomitant injuries in the chest and, most importantly, can be used for surgical planning. Blunt Chest Trauma-Suspected Cardiac Injury CTA Coronary Arteries Coronary CTA evaluates for potential posttraumatic coronary arterial dissection or occlusion resulting in myocardial infarction. There are limited data on the coronary CTA in patients with suspected myocardial infarction in the trauma setting. A case report has described various entities such as intramural hematomas or atypical dissection of the coronary artery [42] and enhancement defects in the myocardium suggestive of myocardial infarction in the setting of trauma. These findings triggered further imaging and subsequent intervention [21] to treat coronary artery dissection following blunt trauma [39]. Several case reports have described the use of coronary angiography as a diagnostic and therapeutic modality [40,43-46] to not only detect coronary artery dissection and thrombosis in patients with ECG abnormalities, or increased serum troponin level, but also treat with angioplasty or coronary artery stent placement. More recently, high-sensitivity cardiac troponins have become the mainstays in an emergency evaluation [7]. FDG-PET/CT Heart Cardiac fluorine-18-2-fluoro-2-deoxy-D-glucose (FDG)-PET/CT may be used to assess myocardial function, perfusion, and viability in the trauma setting. [37,47]. There are no data regarding the use of FDG-PET/CT heart in the setting of blunt chest trauma and suspected cardiac injury. MRI Heart Function and Morphology There are no data regarding the use of MRI heart in the setting of blunt chest trauma and suspected cardiac injury.


Blunt Chest Trauma Suspected Cardiac Injury. A few case reports describe the use of cardiac MR (CMR) in detecting viable myocardium using late gadolinium enhancement because of myocardial infarction in trauma patients [41,46] and a case report describing a heart herniation [48]. CMR is also useful for detecting cardiac injuries, particularly right ventricular injury and pericardial injury, quantifying valvular regurgitation, and detecting typical or atypical aortic dissection in patients. In many instances, the CMR protocol may be shortened to address the clinical question; however, it is still a longer examination than a CT scan. However, CMR may be helpful in selected patients with suspected cardiac trauma and equivocal echo findings. MRI Heart With Function and Inotropic Stress There is no relevant literature regarding the use of CMR with function and inotropic stress in a hemodynamically stable patient with blunt trauma to evaluate suspected cardiac injuries. MRI Heart With Function and Vasodilator Stress Perfusion There is no relevant literature regarding the use of CMR with function and inotropic stress in a hemodynamically stable patient with blunt trauma to evaluate suspected cardiac injuries. Radiography Chest In any trauma setting, chest radiography is the first imaging modality to identify indirect findings that infer cardiac or pericardial injuries. However, the role of chest radiography in blunt cardiac trauma is often limited in quality because of motion artifacts and overlying devices and garments. Longitudinal prospective studies examining the diagnostic yield of imaging in a blunt cardiac trauma have not been possible because identification of indirect findings that infer cardiac injury are rare and often missed and are mainly discussed in case reports. Chest radiography alone has limited ability to detect traumatic cardiac injuries.


Blunt Chest Trauma Suspected Cardiac Injury. SPECT/CT MPI Rest and Stress Single-photon emission computed tomography (SPECT) may be used to assess myocardial function, perfusion, and viability in the trauma setting. The literature for use of SPECT is contradictory. In a prospective study involving 125 patients that evaluated the use of T1-201 thallous chloride SPECT in blunt chest trauma [49], the authors found that 11 out of 75 patients who screened positive and 3 out of 48 patients who screened negative developed serious arrhythmias such as premature ventricular beats and atrial fibrillation. They concluded that SPECT is useful to evaluate myocardial contusion in patients with blunt chest trauma. A meta-analysis study showed that radionuclide results did not correlate with cardiac complications whereas ECG abnormalities and cardiac troponins did in patients with blunt chest trauma [37]. This could be explained by the fact that SPECT better detects left ventricular abnormalities than right ventricular abnormalities, which are more common in blunt cardiac trauma. SPECT/CT MPI Rest Only There is no relevant literature regarding the use of SPECT/CT MPI rest only to evaluate suspected cardiac injuries. Blunt Chest Trauma-Suspected Cardiac Injury US Echocardiography Transesophageal Transesophageal echocardiography (TEE) can be used in the trauma setting; however, it is often time limited because of the hemodynamic instability of the patients, need for sedation, and concern about esophageal injury. TEE is of value when the TTE findings are equivocal and aortic injury is suspected [50]. In a prospective study of 105 patients with severe blunt chest trauma, 20 patients underwent TEE because of suboptimal TTE findings, 9 of whom were diagnosed with a myocardial contusion and 5 with acute aortic injury [50]. TEE is also useful in evaluating right heart and tricuspid valve [51]. There is no evidence to support the use of TEE in the trauma setting for isolated cardiac injury.


Blunt Chest Trauma Suspected Cardiac Injury. Valvular injuries are also rare but have been reported in the literature. Aortic and mitral valves are the most commonly affected, followed by tricuspid and pulmonic valves, because the mural pressure is higher on the left side of the heart [54]. Valvular injuries can present as perivalvular leak, dehiscence because of papillary muscle or chordae tendineae rupture, tearing of valve leaflets, or papillary muscle contusion leading to necrosis. Aortic and pulmonic valves are vulnerable to injury during early diastole and atrioventricular valves are prone to injury during early systole when the intraventricular pressure is increased [7]. All valvular injuries present with signs and symptoms of regurgitation, therefore, it is prudent to perform echocardiography and assess the severity of regurgitation to guide further management with surgical repair in severe cases. Several case reports describe posttraumatic severe mitral regurgitation requiring surgical repair following MVAs [55-57]. A few case reports have described the use of echocardiography for diagnosing wall motion abnormality in the setting of myocardial infarction and coronary artery dissection after blunt chest trauma, especially when myocardial contusion mimics myocardial infarction with elevated cardiac troponins [42,58]. Prompt identification of wall motion abnormality in coronary artery distribution following blunt chest trauma is important for the identification and treatment of coronary artery dissection. Additionally, when a wall motion abnormality is present in the absence of elevated high-sensitivity cardiac troponins, a diagnosis of myocardial concussion can be made. Myocardial concussion does not cause myocardial anatomic injuries that lead to necrosis and elevated high-sensitivity cardiac troponins but instead stretches the cell membrane, leading to activation of ion channels through mechanical- electrical coupling that trigger ventricular arrhythmias [59].


Blunt Chest Trauma Suspected Cardiac Injury. In summary, TTE is the first-line imaging modality used in evaluation of blunt cardiac trauma in patients with abnormal ECG and elevated cardiac troponins. US Echocardiography Transthoracic Stress There is no relevant literature regarding the use of TTE stress in suspected myocardial infarction in the trauma setting. Variant 2: Suspected cardiac injury following blunt trauma, hemodynamically unstable patient. Hemodynamically unstable patients are defined as persistent hypotension (systolic blood pressure <90 mm Hg or mean blood pressure <65 mm Hg) despite fluid resuscitation [17]. Hemodynamically unstable patients with ECG changes and elevated cardiac troponins worrisome for cardiac trauma are usually managed with advanced cardiac life support followed by echocardiography evaluation [7]. On the contrary, hemodynamically unstable patients with normal ECG and cardiac troponins are usually admitted for monitoring and echocardiography is only indicated for unstable patients with rising troponin levels [7]. Blunt Chest Trauma-Suspected Cardiac Injury CT Chest CT chest plays a complementary role in defining the extent of blunt cardiac trauma and is typically reserved for surgical planning in patients with ongoing symptoms and unclear clinical etiology [7]. For this purpose, CT in a hemodynamically unstable patient with blunt trauma is useful despite the lack of relevant literature to support this statement. CT Heart Function and Morphology CT heart in a hemodynamically unstable patient with blunt trauma and possible cardiac injury is useful in clinically indicated scenarios despite the lack of direct evidence. CTA Chest The use of CTA chest is helpful in a hemodynamically unstable patient with blunt trauma and possible cardiac injury if clinically indicated to define the extent of blunt chest trauma and identify concomitant thoracic injuries; it is also helpful for surgical planning.


Blunt Chest Trauma Suspected Cardiac Injury. However, there is no relevant literature to support the use of CTA chest in a hemodynamically unstable patient with blunt trauma and possible cardiac injury. CTA Coronary Arteries The lack of evidence does not support the use of CTA coronary in a hemodynamically unstable patient with blunt trauma and possible cardiac injury, but it could be done if clinically indicated. FDG-PET/CT Heart There is no relevant literature to support the use of FDG-PET/CT in a hemodynamically unstable patient with blunt trauma and possible cardiac injury. MRI Heart Function and Morphology There is no relevant literature to support the use of CMR function and morphology in a hemodynamically unstable patient with blunt trauma and possible cardiac injury. MRI Heart With Function and Inotropic Stress There is no relevant literature regarding the use of CMR stress in a hemodynamically unstable patient with blunt trauma and possible cardiac injury. MRI Heart With Function and Vasodilator Stress Perfusion There is no relevant literature regarding the use of CMR stress in a hemodynamically unstable patient with blunt trauma and possible cardiac injury. Radiography Chest Bedside anteroposterior (AP) chest radiographs are commonly used as a first-line imaging modality in the evaluation of blunt thoracic trauma at most level I trauma centers in the United States, especially in hemodynamically unstable patients [26,60]. AP chest radiographs have limited ability to identify the direct findings of blunt cardiac injuries such as cardiac rupture, coronary artery dissection, pericardial tear, and valvular injuries. However, radiographs have the potential to identify indirect findings that infer cardiac or pericardial injuries. These indirect findings include hemothorax, widened mediastinum, enlarged cardiomediastinal silhouette, abnormal cardiac silhouette contour, changing cardiac position after tube thoracotomy, pneumopericardium, and displaced rib fractures, especially between the third and ninth ribs.


Blunt Chest Trauma Suspected Cardiac Injury. These findings coupled with the appropriate clinical presentation should trigger a further evaluation of potential life-threatening cardiac and pericardial injuries [61-63]. Attention should be paid in patients with cardiac implantable electronic devices for possible device header fracture, lead fracture, or lead migration [64]. A case report of chest trauma that resulted in device malfunction showed an abnormal angulation between the device header and the body of the generator on a lateral chest radiograph [65]. Although an AP chest radiograph is the first-line imaging in trauma patients, it is often limited in quality because of motion artifacts and overlying devices and garments. The evaluation of the mediastinum is also limited with only an AP projection image. Several studies have evaluated the diagnostic yield of the chest radiograph in the assessment of blunt thoracic injuries and have shown the value of using chest radiographs, especially when coupled with abdominal CT, chest CT, or a clinical decision score [23,66-73]. AP chest radiograph has a lower diagnostic yield for occult blunt traumatic injuries than chest CT, missing 80% of cases of hemothorax and 50% of vertebral and rib fractures compared with CT [68,69,72,73]. Hemothorax or hemopericardium can result from cardiac rupture and pericardial tamponade; sternal fracture can result in cardiac contusion or even rupture. Overall, chest radiography alone has limited ability to detect traumatic cardiac injuries. Blunt Chest Trauma-Suspected Cardiac Injury SPECT/CT MPI Rest and Stress There is no relevant literature regarding the use of Tc-99m SPECT/CT MPI rest and stress in a hemodynamically unstable patient with blunt trauma and possible cardiac injury. SPECT/CT MPI Rest Only There is no relevant literature regarding the use of Tc-99m SPECT/CT MPI rest only in a hemodynamically unstable patient with blunt trauma and possible cardiac injury.


Altered Mental Status Coma Delirium and Psychosis.  Introduction/Background Altered mental status (AMS) and coma are terms used to describe disorders of arousal and content of consciousness. AMS may account for up to 4% to 10% of chief complaints in the emergency department (ED) setting and is a common accompanying symptom for other presentations [1,2]. AMS is not a diagnosis but rather a term for symptoms of acute or chronic disordered mentation [1], including confusion, disorientation, lethargy, drowsiness, somnolence, unresponsiveness, agitation, altered behavior, inattention, hallucinations, delusions, and psychosis [3,4]. Some of the most common disorders associated with AMS are underlying medical conditions, substance use, and mental disorders [5]. Validated assessment scales, such as the Richmond Agitation Sedation Scale and Glasgow Coma Scale, may be employed to objectively quantify the severity of symptoms [3,4]. The cause of AMS in patients across all age groups remains undiagnosed in slightly >5% of cases. Overall mortality in patients with AMS is approximately 8.1% and is significantly higher in elderly patients [4]. Two studies found that older patients presenting to the ED with the nonspecific chief complaint of AMS are likely to have delirium [6]. Delirium is a defined and diagnosable medical condition under Diagnostic and Statistical Manual of Mental Disorders, Fifth edition, which includes inattention as a cardinal feature, may fluctuate over the course of day with lucid intervals, and may present with subtle disturbances in consciousness compared with other forms of acute AMS, making detection more difficult and thus easy to miss [3,6]. Delirium is considered a medical emergency. Early detection and accurate diagnosis are extremely important because mortality in patients may be twice as high if the diagnosis of delirium is missed [7].


Altered Mental Status Coma Delirium and Psychosis. Up to 10% to 31% of patients may have delirium at admission, and it may develop in up to 56% of admitted patients [8], particularly following surgery or in the intensive care unit [8]. Delirium is commonly precipitated by 1 or more underlying cause, including another medical condition, intoxication, or withdrawal [9]. Management is based on treatment of the underlying cause, control of symptoms with nonpharmacological approaches, medication when deemed appropriate, and effective aftercare planning [3,6,10]. The economic impact of delirium in the United States is profound, with total costs estimated at $38 to $152 billion each year [11]. New onset psychosis is often listed as a separate subgroup under the AMS category. Delusions and hallucinations are 2 cardinal features of psychotic symptomatology. Additional symptoms may include disorganized speech or thought, disorganized or abnormal motor behavior including catatonia or agitation, and negative symptoms such as diminished expression of emotions [9]. In contrast with other presentations of AMS, awareness and level of consciousness in patients with psychosis are frequently intact [12]. If the psychotic symptoms are related to an underlying psychiatric disorder, such as schizophrenia, bipolar disorder, schizoaffective disorder, or depression with psychotic features, it is termed primary psychosis. Secondary causes of psychosis are thought to be directly related to drug/alcohol use, withdrawal, or an underlying medical cause [1,2] and are not better explained by delirium [9]. Medical conditions that may present with psychotic symptoms include endocrine disorders, autoimmune diseases, neoplasms and paraneoplastic processes, neurologic disorders, infections, genetic or aStanford University School of Medicine, Stanford, California. bPanel Chair, Uniformed Services University, Bethesda, Maryland. cPanel Vice-Chair, Columbia University Medical Center, New York, New York.


Altered Mental Status Coma Delirium and Psychosis. dClinica Family Health, Lafayette, Colorado; American Academy of Family Physicians. eUniversity of Virginia Health System, Charlottesville, Virginia. fUniversity of Michigan, Ann Arbor, Michigan; Commission on Nuclear Medicine and Molecular Imaging. gMontefiore Medical Center, Bronx, New York. hSan Antonio Military Medical Center, San Antonio, Texas; American Academy of Neurology. iUniversity of Washington, Seattle, Washington and University of British Columbia, Vancouver, British Columbia, Canada. jInova Fairfax Hospital, Falls Church, Virginia; American Psychiatric Association. kWeill Cornell Medical College, New York, New York. lThe University of Tennessee Health Science Center, Memphis, Tennessee; Society of General Internal Medicine. mUniversity of Chicago, Chicago, Illinois. nBrigham & Women's Hospital, Boston, Massachusetts; Committee on Emergency Radiology-GSER. oCedars-Sinai, Los Angeles, California; American Geriatrics Society. pNaval Medical Center Portsmouth, Portsmouth, Virginia. qUniversity of Colorado School of Medicine, Aurora, Colorado. rUniversity of Cincinnati Medical Center, Cincinnati, Ohio. sSpecialty Chair, University of Iowa Hospitals and Clinics, Iowa City, Iowa. 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 Altered Mental Status, Coma, Delirium, and Psychosis metabolic disorders, nutritional deficiencies, and drug-related intoxication, withdrawal, side effects, and toxicity. For secondary causes of psychosis, treatment is aimed at the underlying medical cause and control of the psychotic symptoms [12].


Altered Mental Status Coma Delirium and Psychosis. Treatment of primary causes of psychosis involves pharmacologic management with antipsychotic medications, psychological therapy, and psychosocial interventions [13]. This article focuses on the appropriateness of neuroimaging in adult patients presenting with AMS changes including new onset delirium or new onset psychosis. In these cases, imaging is often expedited for initial stabilization and to exclude an intracranial process requiring intervention. The diagnosis of delirium in the ED setting can be missed by inadequate screening [3,14], although ED physicians are moderately accurate at establishing the correct clinical diagnosis for the cause of AMS within the first 20 minutes of the patient encounter [15]. The complete evaluation for underlying causes, such as chest radiography to assess for pneumonia, electrocardiogram to assess for myocardial ischemia, electroencephalography for suspected convulsive or nonconvulsive seizure, and lumbar puncture to assess for central nervous system infection, is beyond the scope of this article [3,7]. OR Discussion of Procedures by Variant Variant 1: Adult. Altered mental status. Suspected intracranial pathology or focal neurologic deficit. Initial imaging. Identifying patients with AMS or delirium secondary to acute intracranial pathology is extremely important to guide management and ensure early appropriate triage. This variant encompasses a select group of patients presenting with acute mental status changes at a relatively higher risk of acute intracranial pathology. The yield of neuroimaging studies in patients with AMS is low. A recent meta-analysis of 25 studies including a total of 79,201 patients with atraumatic AMS showed that 94% had undergone a head CT examination, with relevant abnormal findings in only 11% [24]. In a large study of more than 708,145 adult ED encounters, 58,783 CT head Altered Mental Status, Coma, Delirium, and Psychosis


Altered Mental Status Coma Delirium and Psychosis. examinations were ordered, with an overall critical result yield of 8.0%. CT head examinations performed for a complaint of AMS had a yield of 9.8% [25]. A study of 285 febrile elderly patients with AMS showed abnormal brain imaging in 16.5%. The most common neurological diagnoses in patients admitted to the ED were intracranial hemorrhage (ICH) and ischemic stroke [26]. Lower Glasgow Coma Scale, the presence of lateralizing sign, higher systolic blood pressure, and lower body temperature were significantly associated with abnormal brain imaging in febrile elderly patients with AMS [26]. The prevalence of delirium in the ED ranges from 7% to 35%. Four factors with strong associations with ED delirium are nursing home residence, cognitive impairment, hearing impairment, and a history of stroke [27]. There are a wide range of precipitating factors leading to delirium onset that make evaluation challenging, some of which are life threatening. These may be related to systemic disease, such as sepsis or infection, hypoxia, metabolic derangements, hypoglycemia, hyperglycemia, hyponatremia, hypothermia, acute myocardial infarction, neurologic disease including stroke, ICH, Wernicke encephalopathy (thiamine deficiency), central nervous system infection, seizure, surgery, trauma, drugs such as anticholinergic drugs, sedatives, narcotics, drug or alcohol withdrawal, polypharmacy, environmental factors from restraints, stress or pain, and sleep deprivation. There is relatively little evidence in the literature regarding appropriate use of neuroimaging with new onset delirium. CT Head With IV Contrast A common practice is to perform a noncontrast screening head CT followed by a more sensitive MRI brain examination performed with and without IV contrast in the setting of AMS. In the setting of AMS, contrast- enhanced CT examinations can be considered if intracranial infection, tumor, or inflammatory pathologies are suspected.


Altered Mental Status Coma Delirium and Psychosis. However, the use of contrast-enhanced head CTs as a first-line test in the acute setting does not add significant value over noncontrast head CT examinations [28]. CT Head Without and With IV Contrast A common practice is to perform a noncontrast screening head CT followed by a more sensitive MRI brain examination performed with and without intravenous (IV) contrast in the setting of AMS. There is no relevant literature to support the use of CT head without and with IV contrast in the initial imaging of this clinical scenario. The reported detection of treatment-altering findings on head CT is very low in elderly patients with new onset delirium unless 1 of the following risk factors is present: focal neurologic deficit, history of recent falls or head injury, anticoagulation therapy, signs of elevated intracranial pressure, or significant deterioration of consciousness [8,38-40]. Acute pathology that resulted in a change of management was detected in a small proportion of patients on head CT, including ischemic and hemorrhagic stroke, subdural hematoma, subarachnoid hemorrhage (SAH), encephalitis or meningitis, and cerebral tumors. Therefore, the low diagnostic yield of CT in this setting must be weighed against the risk of possible, preventable morbidity [8,10], acknowledging that patients may not have clinical signs on examination that predict a focal pathology [34]. MRI Head With IV Contrast There is no relevant literature to support the use of MRI head performed only with IV contrast in this clinical scenario. Altered Mental Status, Coma, Delirium, and Psychosis MRI Head Without and With IV Contrast MRI examinations without and with IV contrast may be performed if intracranial infection, tumor, inflammatory lesions, or vascular pathologies are suspected.


Altered Mental Status Coma Delirium and Psychosis. In patients with delirium, brain MRI without and with IV contrast may be helpful for the definitive characterization of a focal lesion identified on initial noncontrast CT or in patients with known cancer history [10]. In a simulated decision-making study using a prospective intensive care unit cohort, a panel of neurocritical experts first reviewed clinical information (without MRI) from 75 patients with acute disorder of consciousness patients and made decisions about diagnosis, prognosis, and treatment. Review of head MRI examinations led to changes in clinical management of 76% of patients including revised diagnoses in 20%, revised levels of care in 21%, improved diagnostic confidence in 43%, and improved prognostications in 33% [37]. However, decisions were revised more often with stroke (which commonly presents with focal neurological deficits) than with other brain injuries. Many of the abnormal findings in the literature for this topic included small ischemic infarcts [29,35,36]. Notably, a retrospective study found that 70% of patients who had a missed ischemic stroke diagnosis presented with AMS [33]. MRI of the brain is complementary to an abnormal head CT for the evaluation of suspected intracranial mass lesions, intracranial infection, nonspecific regions of edema, ischemia, and cases of ICH when an underlying lesion is suspected [38]. MRI may also be considered as a first-line test in certain situations, such as a clinically stable patient with known malignancy, HIV, or endocarditis. Noncontrast MRI examinations of the brain are usually sufficient in the assessment of intracranial complications related to hypertensive emergency, including posterior reversible encephalopathy syndrome. In patients with new onset delirium, the reported yield of brain MRI is very low in the absence of a focal neurologic deficit or history of recent falls.


Altered Mental Status Coma Delirium and Psychosis. In a small proportion of patients, brain MRI did reveal acute pathology possibly accounting for delirium, including ischemic and hemorrhagic stroke, subdural hematoma, SAH, septic emboli, encephalitis, meningitis, cerebral metastases, primary brain tumor, pineal tumor, and a large meningioma [34]. MRI may be helpful for further evaluation of an abnormality detected on noncontrast CT in the workup of new onset delirium, such as space-occupying lesions or infection. CT Head With IV Contrast Contrast-enhanced CT examinations may be considered if clinical concern exists for progression of intracranial infection, such as abscesses or empyema, tumor, or inflammatory conditions. Advantages of CT are fast examination times and less susceptibility to motion artifact compared with MRI. Disadvantages of CT include less sensitivity in detection of acute ischemia and enhancement compared with MRI [30]. Overall, MRI is considered superior in this clinical scenario. CT Head Without and With IV Contrast A common practice is to perform a noncontrast screening head CT followed by a more sensitive MRI brain examination performed with and without IV contrast in the setting of AMS. There is no relevant literature to support the use of CT head without and with IV contrast in the initial imaging of this clinical scenario. CT Head Without IV Contrast CT is the first-line imaging test of choice for evaluating suspected progressive ICH, mass effect, or hydrocephalus in the emergent setting. Noncontrast head CT examinations are able to depict possible complications of a wide variety of intracranial pathology, including progressive mass effect, increasing edema, hydrocephalus, new or enlarging ICH, and progressive ischemia. However, the literature search did not identify any studies regarding the 6 Altered Mental Status, Coma, Delirium, and Psychosis use of CT in the evaluation of acute or worsening mental status changes in a patient with known intracranial pathology.


Altered Mental Status Coma Delirium and Psychosis. MRI Head With IV Contrast There is no relevant literature to support the use of MRI head performed only with IV contrast in this clinical scenario. MRI Head Without and With IV Contrast MRI is the imaging test of choice in the evaluation of suspected progressive inflammatory conditions, such as multiple sclerosis or neuropsychiatric systemic lupus erythematosus. In the assessment of known ICH, MRI is usually not required unless there is suspicion for an underlying mass or lesion or if axonal shear injury is suspected. MRI without and with IV contrast may be performed if intracranial infection, tumor, inflammatory lesions, or vascular pathologies are suspected. MRI Head Without IV Contrast MRI is complementary to CT in the evaluation of suspected progression of intracranial mass lesions, infection, and ischemia and may be performed as a first-line test instead of CT. However, the literature search did not identify any studies regarding the use of MRI in the evaluation of acute or worsening mental status changes in a patient with known intracranial pathology. Advantages of MRI include higher sensitivity for the detection of ischemia, encephalitis, subtle cases of SAH, and enhancement of pathology compared with CT and the potential to use advanced imaging applications that may provide critical information, such as diffusion-weighted imaging, MR perfusion, susceptibility-weighted sequences, and MR spectroscopy. Disadvantages of MRI include longer examination time, susceptibility to motion artifacts, and implanted devices that are not MRI safe [2]. Variant 3: Adult. Altered mental status. Suspected medical illness or toxic-metabolic cause. Initial imaging. Acute mental status changes may be triggered by a wide range of medical conditions, including drugs and intoxication, system or organ dysfunction, and metabolic or endocrine factors.


Altered Mental Status Coma Delirium and Psychosis. This variant encompasses a subgroup of patients presenting with acute mental status changes at low risk of acute intracranial pathology. CT Head With IV Contrast The literature search did not identify any studies regarding the use of contrast-enhanced CT relevant to this variant, and contrast-enhanced CT examinations are not performed as a first-line test in this setting. CT Head Without and With IV Contrast A common practice is to perform a noncontrast screening head CT followed by a more sensitive MRI brain examination performed with and without IV contrast in the setting of AMS. There is no relevant literature to support the use of CT head without and with IV contrast in the initial imaging of this clinical scenario. CT Head Without IV Contrast ED physicians are moderately accurate at establishing the correct clinical diagnosis for the cause of AMS within the first 20 minutes of the patient encounter [15]. A large proportion of misdiagnoses in this study were deemed insignificant because of confusing various forms of isolated or mixed intoxication. Although CT head may be useful in this scenario, deferring head CT imaging while observing if intoxicated patients symptomatically improve may be a safe practice and may prevent the need for imaging in large percentage of intoxicated patients [39]. MRI Head With IV Contrast There is no relevant literature to support the use of MRI head performed only with IV contrast in this clinical scenario. MRI Head Without and With IV Contrast There is no relevant literature to support the use of MRI head without and with IV contrast in this clinical scenario.


Altered Mental Status Coma Delirium and Psychosis. MRI Head Without IV Contrast There may be unique instances where a brain MRI examination may be useful in confirming a suspected clinical diagnosis responsible for AMS, such as carbon monoxide poisoning, Wernicke encephalopathy (thiamine deficiency) [40], drug toxicity including medications (eg, methotrexate, metronidazole) and illegal drug use, central pontine myelinolysis, or additional metabolic disorders. However, the literature search did not identify any studies regarding the use of MRI relevant to this variant. Altered Mental Status, Coma, Delirium, and Psychosis Variant 4: Adult. Altered mental status despite clinical management of known medical illness or toxic- metabolic cause. Initial imaging. This is a challenging clinical scenario in which common and treatable causes of AMS have been deemed unlikely, and a more exhaustive evaluation is required to find the precipitating cause of AMS. Clinical suspicion for a neurologic cause of AMS may be in an intermediate category. CT Head With IV Contrast Contrast-enhanced CT examinations are usually not performed as a first-line test in this setting but may be considered as a second-line test to assess abnormalities found on the screening head CT and for patients unable or unwilling to have MRI [28]. Evidence guiding appropriate imaging recommendations in this variant is limited because most studies in the literature search sampled undifferentiated patient populations with a broad range of risk factors and are not directly applicable to this variant [2,29,31-33]. CT Head Without and With IV Contrast A common practice is to perform a noncontrast screening head CT followed by a more sensitive MRI brain examination performed with and without IV contrast in the setting of AMS. There is no relevant literature to support the use of CT head without and with IV contrast in the initial imaging of this clinical scenario.


Altered Mental Status Coma Delirium and Psychosis. MRI Head With IV Contrast There is no relevant literature to support the use of MRI head performed only with IV contrast in this clinical scenario. MRI Head Without and With IV Contrast MRI examinations without and with IV contrast may be performed if intracranial infection, tumor, inflammatory lesions, or vascular pathologies are suspected. However, the literature search did not identify any studies regarding the use of contrast-enhanced MRI relevant to this variant. Noncontrast MRI examinations of the brain are usually sufficient in the assessment of intracranial complications related to hypertensive emergency, including posterior reversible encephalopathy syndrome. Variant 5: Adult. New onset psychosis. Initial imaging. This variant addresses the role of neuroimaging in the assessment for secondary causes of new onset psychosis in the ED or inpatient setting. Some of the reported organic causes of psychosis include tumors or infarcts in specific areas of the brain, such as the temporal lobe, systemic lupus erythematosus, encephalitis, multiple sclerosis, Wilson disease, Huntington disease, or metachromatic leukodystrophy [42-44]. Patients with new onset psychosis who have suspected stroke, focal neurologic deficit, seizure, head trauma, or headache should refer to the respective ACR Appropriateness Criteria as appropriate: ACR Appropriateness CT Head With IV Contrast Contrast-enhanced CT is generally not helpful for new onset psychosis in the absence of focal neurologic deficits. CT Head Without and With IV Contrast There is no relevant literature to support the use of CT head without and with IV contrast in the initial imaging of this clinical scenario. MRI Head With IV Contrast There is no relevant literature to support the use of MRI head performed only with IV contrast in this clinical scenario.


Fever Without Source or Unknown Origin Child.  Although FWS is mostly self-limited and of little clinical concern, the burden on clinicians is to decide which children actually have a serious bacterial infection (SBI) that requires antibiotic treatment and even hospitalization [18,19]. Febrile neonates are at higher risk; the reported incidence of SBI in all febrile neonates presenting to emergency departments varies between 6% and 28% [17,20]. In children, the usual sources/causes of SBI are urinary tract infection, pneumonia, bloodstream infection, and meningitis. With the advent of vaccines for the most common pathogenic serotypes of H. flu and S. pneumonia, the incidence of SBI has dropped significantly [2,3,6,10,13,14]. Although it is implied by the definition of FWS that the etiology of fever is unknown, many studies and guidelines include children with respiratory symptoms [2,3,5,6,8,16,21-24]. For this reason, we were compelled to include in our guidelines for FWS children with respiratory symptoms. Overview of Imaging Modalities A detailed and thorough history and physical examination is the most important component of the diagnostic evaluation of a child with FWS or FUO. Chest radiographs have a role in evaluation of occult pneumonia and should be performed in neonates with FWS and respiratory symptoms and in selected older children with high Reprint requests to: publications@acr.org Discussion of Imaging Modalities by Variant Variants 1 and 2: Neonate younger than 1 month of age with FWS. In febrile neonates younger than 28 days, history and physical examination alone may not be able to completely exclude SBI, even in children who appear clinically well or mildly ill [40]. Therefore, a full sepsis workup is frequently performed. This includes complete blood count, blood culture, urinalysis and urine culture, lumbar puncture with evaluation of cerebrospinal fluid, and administration of antibiotics in the emergency department, followed by hospitalization pending results of cultures [2,3,8,9,22,28].


Fever Without Source or Unknown Origin Child. A chest radiograph is indicated in neonates with FWS and respiratory symptoms [3,21]. In addition, a chest radiograph in a septic-appearing neonate with FWS may disclose an occult pneumonia [6,8,16,28]. Some investigators advocate routine chest radiographs in all neonates with FWS because these infants are relatively immunocompromised compared with older infants and children, and the consequences of a missed SBI or occult infection are felt to be greater [6]. A chest radiograph can help exclude congenital or acquired cardiac disease in a child who is febrile and ill. However, the benefit of routine use of chest radiography in neonates without respiratory symptoms has not been established [3,21]. Bramson et al [43] combined their data with those of 2 prior studies [42,47] and subjected these to a statistical meta-analysis. The larger number of patients in the combined study allowed more valid conclusions concerning the accepted practice of performing chest radiographs in febrile infants as part of the sepsis workup. These 3 series had 671 infants. In 361 infants with no clinical evidence of pulmonary disease on history and physical examination, all had normal chest radiographs. A finding of only hyperinflation on a chest radiograph was interpreted as normal because it was felt that the infants would likely have a viral illness or reactive airway disease and would not usually be receiving antibiotics, unlike older children and adults [48]. Bramson et al [43] indicated that a chest radiograph in a patient with no pulmonary symptoms or signs would be positive <1.2% of the time. In the current era of S. pneumonia and H. flu vaccine use, this rate might fall even further. Murphy et al [49] found an incidence of radiographic pneumonia in 5.3% of 2,128 children under 10 years of age with no lower respiratory symptoms (other than cough) and concluded that there was a low utility in obtaining chest radiographs in febrile children without cough.


Fever Without Source or Unknown Origin Child. A longer duration of cough, fever, and leukocytosis increased the likelihood of radiographic pneumonia in these children. The practice of routinely obtaining a chest radiograph has been challenged. Korones et al [61] evaluated 54 children with cancer who were hospitalized for hundreds of episodes of fever and neutropenia. They found an incidence of radiographic pneumonia of only 3% to 6%. The children without respiratory findings had no evidence of pneumonia on chest radiographs, and children who did not have chest radiographs showed no significant outcome differences from those who did. Philips et al [62] confirmed in a meta-analysis the low use of routine chest radiographs in this setting but stated that in those with a predisposition to pneumonia and those not responding to a short empiric course of antibiotics, chest radiographs should be performed despite the absence of clinical signs of a lower respiratory tract infection. Children with neutropenia and FWS often undergo advanced imaging, but there is little evidence-based data about which studies are most efficacious. In their 2002 guidelines (not pediatric specific), the Infectious Diseases Society of America noted that one-half of febrile neutropenic patients with normal chest radiographs will have evidence of pneumonia on chest CT [63]. Archibald et al [36] evaluated the performance of CT in 83 neutropenic pediatric cancer patients who had 109 instances of fever lasting 4 days or more. Rates of positive CT findings varied by body region: head and neck, 8%; paranasal sinus, 41%; chest, 49%; and abdomen, 19%. Findings on paranasal sinus and chest CT led to changes in therapy in 24% and 30% of cases, respectively. However, they added that CT was rarely abnormal in the absence of localizing signs or symptoms and that in the absence of symptoms, CT findings rarely lead to therapeutic changes.


Fever Without Source or Unknown Origin Child. In a more recent study, Agrawal et al [35] demonstrated a similar distribution of positive findings among body regions but found that only 2 of the initial positive CT scans led to a change in management (6.5% of positive scans, 0.8% of all initial scans). They therefore recommend limiting initial empiric CT imaging to the chest only in patients without localizing signs or symptoms. Regarding the use of FDG-PET/CT, Blokhuis et al [39] found a 78% sensitivity and 67% specificity in 12 of such children. Variant 6: Infant or child more than 1 month of age with fever of unknown origin (FUO). Occult infection is the usual cause of FUO in children and is less commonly due to rheumatologic, autoimmune, neoplastic, or other inflammatory conditions [9,20,24,27,66,67]. Some children never have a specific diagnosis reached [9,24]. Evaluation of FUO in children is mainly based on thorough physical examination, history, and laboratory studies such as a complete blood cell count and peripheral smear, erythrocyte sedimentation rate, C- reactive protein, aerobic blood cultures, urinalysis, urine culture, tuberculin skin test, electrolytes, blood urea nitrogen, creatinine, hepatic enzymes, and human immunodeficiency virus serology [9,20,24,27,68,69]. Chest radiographs are usually obtained to evaluate for occult pneumonia and lymphadenopathy. Although many studies describe the clinical course of such patients, few of them examine the utility of diagnostic imaging modalities in these difficult patients. In general, if a detailed review of the history, physical examination, and screening evaluation fail to suggest a diagnosis, more extensive imaging can be considered. This includes abdominal ultrasound (US) and CT studies of the chest, abdomen, and paranasal sinus [4]. Steele et al [70] evaluated 109 children with FUO with conventional radionuclide techniques. These studies were often positive but rarely led to an unsuspected diagnosis.


Imaging after Mastectomy and Breast Reconstruction.  Introduction/Background Mastectomy may be performed to treat breast cancer [1] with some authors reporting increasing rates of mastectomy relative to breast conservation in the United States [2-4]. Mastectomy may also be performed as a prophylactic approach in women with a high lifetime risk of developing breast cancer. Mastectomy techniques have changed over time with radical mastectomy replaced by modified radical mastectomy and with options such as skin-sparing and nipple-sparing procedures now available [5]. In addition, mastectomies may be performed with or without reconstruction. Reconstruction approaches differ and may be autologous, involving a transfer of tissue (skin, subcutaneous fat, and muscle) from other parts of the body to the chest wall. Examples of autologous reconstruction include latissimus dorsi flaps, transverse rectus abdominis myocutaneous (TRAM) flaps, and variants such as deep inferior epigastric perforator flaps [1]. Reconstruction may also involve implants. Implant reconstruction may occur as a single procedure or as multistep procedures with initial use of an adjustable tissue expander allowing the mastectomy tissues to be stretched without compromising blood supply. Ultimately, a full-volume implant, which may be saline, silicone, or both, will be placed. Implant reconstruction often involves the placement of acellular matrix, which can increase risk of seroma formation and occasionally is visible on imaging. Reconstructions with a combination of autologous and implant reconstruction may also be performed. Other techniques such as autologous fat grafting may be used to refine both implant and flap-based reconstruction [6]. Although most of the breast tissue is removed after mastectomy, recurrence may occur in residual tissue. The majority of recurrences in the reconstructed breast will be found in the skin and the subcutaneous tissues followed by recurrences deep to the pectoralis muscle [7].


Imaging after Mastectomy and Breast Reconstruction. Recurrence rates are reported to be approximately 1% to 2% annually for both mastectomy and mastectomy with reconstruction, and overall recurrence has been reported at between 2% to 15% and has been noted to vary based on the initial cancer type and stage as well as follow-up period of the study [5,7-13]. Clinical evaluation has been a mainstay of evaluation of the postmastectomy breast [4], and the appropriate surveillance imaging strategy for patients with a history of mastectomy with or without reconstruction is an evolving topic, with evidence predominantly drawn from small retrospective studies. Finally, women who have undergone mastectomy with or without reconstruction may present with symptomatic concerns, both in the immediate postoperative period and later. Sequalae of the surgery, such as hematomas, infections, and most commonly in the early postoperative period, fat necrosis [7], may present as palpable findings. Recurrent disease may also present as a palpable lump [7,14]. OR aNew York University School of Medicine, New York, New York. bPanel Chair, Alpert Medical School of Brown University, Providence, Rhode Island. cPanel Vice-Chair, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida. dUniversity of Louisville School of Medicine, Louisville, Kentucky; Society of Surgical Oncology. eUniversity of Cincinnati, Cincinnati, Ohio. fAlpert Medical School of Brown University, Providence, Rhode Island. gNorthwestern University Feinberg School of Medicine, Chicago, Illinois; American College of Physicians. hMemorial Sloan Kettering Cancer Center, New York, New York. iUniversity of Michigan, Ann Arbor, Michigan. jBeth Israel Deaconess Medical Center, Boston, Massachusetts. kStamford Hospital, Stamford, Connecticut; American College of Surgeons. lWomen and Infants Hospital, Providence, Rhode Island; American College of Obstetricians and Gynecologists. mRadiology Associates of Tallahassee, Tallahassee, Florida.


Imaging after Mastectomy and Breast Reconstruction. nCentral Oregon Radiology Associates, Bend, Oregon. oSpecialty Chair, NYU Clinical Cancer Center, New York, New York. 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 FDG-PET Breast Dedicated There is no relevant literature to support the use of fluorine-18-2-fluoro-2-deoxy-D-glucose (FDG)-PET breast for screening in this clinical setting. Mammography Screening Annual screening with 2-D mammography or DBT is recommended for the contralateral native breast. There is insufficient evidence to support screening with 2-D mammography of the postmastectomy side. Although one small retrospective study has shown a small increase in cancer detection with mammography in postmastectomy patients [16], another study has demonstrated no benefit [8]. MRI Breast Without IV Contrast There is no relevant literature to support the use of MRI breast without intravenous (IV) contrast for screening in this clinical setting. MRI Breast Without and With IV Contrast There is no relevant literature to support the use of MRI without and with IV contrast, specifically for screening the postmastectomy nonreconstructed breast. However, based on breast cancer risk, including factors such as age at cancer diagnosis, breast density, and family history, women with a personal history of cancer may undergo MRI for the contralateral native breast [17]. In this setting, the postmastectomy breast may be imaged and evaluated on MRI with potential for malignancy detection and characterization [18]. Sestamibi MBI There is no relevant literature to support the use of Tc-99m sestamibi molecular breast imaging (MBI) for screening in this clinical setting.


Imaging after Mastectomy and Breast Reconstruction. US Breast There is insufficient evidence to support the use of ultrasound (US) for screening in this setting. There is a paucity of evidence-based literature [16,18-20], with only a few small retrospective studies finding utility in screening with US in this setting. A subset of a retrospective study evaluated 67 women postmastectomy who had suspected recurrence and underwent US imaging; although some of these women were symptomatic, 7 recurrent impalpable cancers were detected only on US in the cohort [16]. This study also found 3/61 cancers detected only on mammography and not on US. A study of 1,796 US examinations in 874 asymptomatic patients (median follow-up of 37 months) found 15 clinically occult recurrences detected with US in 15 patients (cancer detection rate of 1.7% per patient and 0.8% per examination) [19]. Lee et al [20] evaluated 1,180 consecutive screening USs of the mastectomy site and the ipsilateral axillary fossa in 468 asymptomatic women and found 10 malignancies with a similar cancer detection rate of 2.1% per patient and 0.8% per screening examination. FDG-PET Breast Dedicated There is no relevant literature to support the use of FDG-PET breast for screening in this clinical setting. Digital Breast Tomosynthesis Screening Although insufficient studies have been performed to assess the utility of DBT in this setting, multiple investigations have demonstrated that DBT is helpful in the screening setting of the native breast, thus decreasing recall rates and increasing cancer detection rates compared to a conventional mammographic workup [21-26]. Mammography Screening Evidence is limited, but a few retrospective studies suggest a benefit to screening women with autologous reconstruction after mastectomy for cancer in the reconstruction side. Helvie et al [27] looked at 214 consecutive screening mammograms in 113 women with TRAM flap reconstructions, 106 (94%) of which were performed after mastectomy for cancer.


Imaging after Mastectomy and Breast Reconstruction. The cancer detection rate was 0.9% per screen and 1.9% per patient (2/106, 95% confidence interval [CI]: 0.33%, 7.32%) and positive predictive value (PPV) of biopsy was 33% (95% CI: 6%, 76%). Noroozian et al [10] in a larger study of 515 women and 618 mastectomies with reconstruction, 485 of which were performed for cancer, found the cancer detection rate of screening mammography to be 1.5/1,000 screening mammograms, comparable to that for one native breast of age-matched women. However, Freyvogel et al [28] retrospectively evaluated 541 postmastectomy and autologous reconstruction patients. Of these, 397 patients had screening mammography and 537 patients underwent routine clinical examination. Of the patients in the cohort, 26 of 27 (96.3%) had a clinically detectable recurrence, and the two cancers detected on screening were also palpable on follow-up clinical examination. Lee et al [29] evaluated 554 mammograms (265 TRAM flap reconstructions); no cancers were detected through screening and no interval nonpalpable recurrent breast cancers missed at mammography were identified, yielding a 0% rate of detection (exact 95% CI: 0.0%, 1.4%). The authors concluded that screening this population is less effective than screening average-risk women in their 40s, although it should be noted that the upper end of the CI is in line with the rates reported by the other studies mentioned above. Of note, there are no studies specifically evaluating decrease in mortality from screening women in this setting. MRI Breast Without IV Contrast There is no relevant literature to support the use of MRI of the breast without IV contrast for screening in this clinical setting. MRI Breast Without and With IV Contrast There is insufficient evidence to support the use of MRI without and with IV contrast for screening in this setting.


Imaging after Mastectomy and Breast Reconstruction. Based on breast cancer risk, including factors such as age at cancer diagnosis, breast density, and family history, women with a personal history of cancer may undergo MRI for the contralateral native breast [17]. In this setting, MRI will also allow for evaluation of the reconstructed breast and may be able to demonstrate recurrent malignancy, although the literature is scant with only several small studies and case reports [30,31]. Reiber et al [31], for example, used MRI to evaluate 41 patients with flap reconstructions, finding one mammographically and sonographically occult cancer in a patient with a latissimus dorsi flap. However, MRI also generated three false- positive biopsies. Sestamibi MBI There is no relevant literature to support the use of Tc-99m sestamibi MBI for screening in this clinical setting. US Breast There is no relevant literature to support the use of US for screening in this clinical setting. Imaging after Mastectomy and Breast Reconstruction Digital Breast Tomosynthesis Screening There is no relevant literature to support the use of DBT for screening in this clinical setting. Mammography Screening There is no relevant literature to support the use of mammography for screening in this clinical setting. FDG-PET Breast Dedicated There is no relevant literature to support the use of FDG-PET breast for screening in this clinical setting. MRI Breast Without IV Contrast There is no relevant literature to support the use of MRI without IV contrast for screening in this clinical setting. Sestamibi MBI There is no relevant literature to support the use of Tc-99m sestamibi MBI for screening in this clinical setting. US Breast There is no relevant literature to support the use of US for screening in this clinical setting. FDG-PET Breast Dedicated There is no relevant literature to support the use of FDG-PET breast for screening in this clinical setting.


Imaging after Mastectomy and Breast Reconstruction. Digital Breast Tomosynthesis Screening There is no relevant literature to support the use of DBT for screening in this clinical setting. Mammography Screening There is no relevant literature to support the use of mammography for screening in this clinical setting. MRI Breast Without IV Contrast There is no relevant literature to support the use of MRI without IV contrast for screening in this clinical setting. MRI Breast Without and With IV Contrast There is insufficient evidence to support the use of MRI without and with IV contrast for breast cancer screening in this setting. Sestamibi MBI There is no relevant literature to support the use of Tc-99m sestamibi MBI for screening in this clinical setting. US Breast There is no relevant literature to support the use of US for screening in this clinical setting. Digital Breast Tomosynthesis Screening There is no relevant literature to support the use of DBT for screening in this clinical setting. Mammography Screening There is insufficient evidence to support the use of mammography for breast cancer screening in this population. A recent study by Noroozian et al [10] found no evidence to support the use of screening mammography in women who had undergone bilateral prophylactic mastectomy with autologous reconstruction. Of 133 prophylactic mastectomies with autologous reconstruction (805 mammograms), the cancer detection rate with mammography was 0%. FDG-PET Breast Dedicated There is no relevant literature to support the use of FDG-PET breast for screening in this clinical setting. MRI Breast Without IV Contrast There is no relevant literature to support the use of MRI without IV contrast for screening in this clinical setting.


Imaging after Mastectomy and Breast Reconstruction. MRI Breast Without and With IV Contrast Although there may be residual breast glandular tissue after mastectomy and MRI may be useful in delineating the amount of this residual tissue in women after prophylactic mastectomy [35], there is insufficient evidence to support the use of MRI breast without and with IV contrast for breast cancer screening in this population. A small retrospective study of breast MRI surveillance examinations performed in a subset of women who underwent bilateral mastectomy for either cancer or prophylaxis and had either implant, flap, or mixed reconstructions found no cancers that were not also evident on clinical examinations [33]. Sestamibi MBI There is no relevant literature to support the use of Tc-99m sestamibi MBI for screening in this clinical setting. US Breast There is no relevant literature to support the use of US for screening in this clinical setting. Digital Breast Tomosynthesis Screening There is no relevant literature to support the use of DBT for screening in this clinical setting. Mammography Screening There is no relevant literature to support the use of mammography for screening in this clinical setting. FDG-PET Breast Dedicated There is no relevant literature to support the use of FDG-PET breast for screening in this clinical setting. MRI Breast Without IV Contrast There is no relevant literature to support the use of MRI without IV contrast for screening in this clinical setting. MRI Breast Without and With IV Contrast There is insufficient evidence to support screening for women with prophylactic mastectomy and implant reconstruction. It has been suggested that the yield of screening in this setting is especially low in the setting of retropectoral implant placement, in which recurrences are most likely to be clinically palpable [33,34].


Imaging after Mastectomy and Breast Reconstruction. A small retrospective study of breast MRI in 48 women status post bilateral mastectomy with and without reconstruction, some of whom underwent surveillance MRI, found no malignancy that was not also evident on clinical examination [33]. A retrospective study of 159 women status post bilateral mastectomy and reconstruction and undergoing MRI surveillance found no cancers in the subset of 31 women who had mastectomy performed for risk reduction [34]. Imaging after Mastectomy and Breast Reconstruction Sestamibi MBI There is no relevant literature to support the use of Tc-99m sestamibi MBI for screening in this clinical setting. US Breast There is no relevant literature to support the use of US for screening in this clinical setting. Variant 7: Female. Palpable lump or clinically significant pain on the side of the mastectomy without reconstruction. Initial imaging. Digital Breast Tomosynthesis Diagnostic There is insufficient evidence to support the use of DBT as the initial imaging modality in women with palpable lumps or clinically significant pain on the side of the mastectomy. However, DBT can be useful in the diagnostic setting. It is known to improve lesion characterization in noncalcified lesions and to improve cancer detection when compared to conventional mammographic workup [36-38]. Mammography Diagnostic There is limited evidence to support the use of diagnostic mammography as the initial imaging modality in this clinical setting. A study of 67 women who underwent mastectomy and were suspected of recurrence found 3/61 cancers detected only on mammography and not on US [16]. Another study evaluating palpable lumps in 101 patients who had undergone mastectomy, the majority of whom (69%) had reconstruction with implants, demonstrated that mammography could be useful to confirm benign findings such as fat necrosis and benign calcifications identified on US [39]. However, diagnostic mammography yielded no additional cancers beyond those depicted on US.


Imaging after Mastectomy and Breast Reconstruction. FDG-PET Breast Dedicated There is no relevant literature to support the use of FDG-PET breast in this clinical setting. MRI Breast Without IV Contrast There is no relevant literature to support the use of MRI without IV contrast in this clinical setting. MRI Breast Without and With IV Contrast There is no evidence to support the use of MRI breast without and with IV contrast as the initial imaging modality in women with palpable lump or clinically significant pain on the mastectomy side. However, MRI may help characterize malignancy once identified and has been found to be more accurate than US in delineating extent of disease, although there is a paucity of evidence-based literature [18]. Sestamibi MBI There are a few small retrospective studies evaluating the use of Tc-99m sestamibi MBI in the context of a clinically suspicious lump. For example, Usmani et al [40] looked at 41 consecutive postmastectomy patients and found a sensitivity of 89%, specificity of 92%, PPV of 96%, negative predictive value (NPV) of 80%, and accuracy of 90% with Tc-99m sestamibi MBI. This was compared to US, which had a lower sensitivity of 86%, specificity of 77%, PPV of 89%, NPV of 71%, and accuracy of 83% (P = . 001). The authors found that the combined sensitivity was 100%, specificity 77%, PPV 90%, NPV 100%, and accuracy 93%. However, there is insufficient evidence to support the use of Tc-99m sestamibi MBI as the initial imaging modality in this setting. US Breast A retrospective evaluation of 118 palpable lumps in 101 patients, 9% of whom were status postmastectomy found 13 cancers in the mastectomy bed in women with a history of cancer. US had a high NPV of 97% and a PPV of 27% [39]. Gweon et al [41] evaluated both palpable and nonpalpable US BI-RADS categorization of lesions 4a and above at the mastectomy site and found 9/20 (45%) malignancies among palpable lesions; they also found that 100% of all BI-RADS 4c and BI-RADS 5 lesions proved to be malignant.


Imaging after Mastectomy and Breast Reconstruction. In the event of an indeterminate US finding or an US finding suggestive of fat necrosis, diagnostic mammography or DBT may be helpful for lesion characterization and may preclude the need for biopsy if a clearly benign finding such as an oil cyst is identified. Imaging after Mastectomy and Breast Reconstruction Digital Breast Tomosynthesis Diagnostic There is insufficient evidence to support the use of DBT as the initial imaging modality for women with palpable lumps or clinically significant pain on the side of the mastectomy with reconstruction. However, DBT can be useful in the diagnostic setting. It is known to improve lesion characterization in noncalcified lesions and to improve cancer detection when compared to conventional mammographic workup [36-38]. Mammography Diagnostic There is limited evidence to support the use of diagnostic mammography as the initial imaging modality in this clinical setting. Mammography may be helpful in identifying a benign postsurgical etiology of a palpable concern such as fat necrosis or oil cyst. For example, a study evaluating palpable lumps in 101 patients who had undergone mastectomy, the majority of whom (69%) had reconstruction with implants, demonstrated that mammography could be useful to confirm benign findings such as fat necrosis and benign calcifications identified on US [39]. However, the study also showed that diagnostic mammography yielded no additional cancers beyond those depicted on US. In another small study, Edeiken et al [42] found that mammography depicted only 14 of 25 (56%) of the recurrences visualized on US in women who had undergone autogenous myocutaneous flaps after mastectomy. FDG-PET Breast Dedicated There is no relevant literature to support the use of FDG-PET breast as the initial imaging modality in this clinical setting. MRI Breast Without and With IV Contrast There is insufficient evidence for MRI without and with IV contrast as the initial imaging modality in this setting.