Developmental Dysplasia of the Hip Child. Radiography Pelvis Shortly after the appearance of the ossific nucleus, pelvic radiography becomes the preferred imaging modality as it facilitates the assessment of the femoral head ossific nucleus and the development of the proximal femur and bony acetabular morphology [1]. There is ongoing debate regarding the necessity of serial radiographic studies for


Developmental Dysplasia of the Hip Child. Variant 6: Child, younger than 6 months of age. Known diagnosis of DDH, nonoperative surveillance imaging in harness. The treatment algorithm for DDH varies among practices but typically includes a trial of nonoperative management using abduction splinting, often with a Pavlik harness. The efficacy of the Pavlik harness decreases with age. It is most effective if the harness is applied before 6 weeks of age, and the harness can be used up to 6 months of age. The overall success rate of the harness ranges from 67% to 83% [28]. Surgical intervention is typically reserved for children with severe dysplasia or dislocation, late presentation or diagnosis, or failed nonoperative management [73].


Developmental Dysplasia of the Hip Child. US Hips In children who are undergoing nonoperative treatment with Pavlik harness, US can be used to confirm concentric hip reduction [74,75], assess treatment response [73,76-79], and identify signs of therapy failure [80]. Predictors of failure include low postreduction alpha angle and <20% femoral head coverage [81]. US is typically performed without applied stress to the hips and with the child either in or out of brace, depending on the discretion of the referring provider.


Developmental Dysplasia of the Hip Child. Radiography Pelvis Radiography is not the preferred modality for monitoring children undergoing nonoperative treatment using a harness [76,82] because of the delay in the appearance of the femoral head ossific nucleus and suboptimal patient positioning (within the harness). Rather, radiographs are often obtained at or near the conclusion of the treatment to document bony acetabular development and to provide a baseline for future surveillance [59].


Developmental Dysplasia of the Hip Child. CT Pelvis There is no relevant literature regarding the use of CT to monitor children with DDH who are being treated nonoperatively using a harness.


Developmental Dysplasia of the Hip Child. MRI Pelvis There is no relevant literature regarding the use of MRI to monitor children with DDH who are being treated nonoperatively using a harness.


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


Developmental Dysplasia of the Hip Child. For additional information on the Appropriateness Criteria methodology and other supporting documents go to www.acr.org/ac.


Acute Nonlocalized Abdominal Pain

Acute Nonlocalized Abdominal Pain. Associated fever with abdominal pain constitutes an even more challenging clinical situation. Fever raises clinical suspicion of an intra-abdominal infection, abscess, or other condition that may need immediate surgical or medical attention. When fever is present, the need for quick, definitive diagnosis is considerably heightened. Imaging is especially helpful in the elderly with acute abdominal pain and fever. In this population, many laboratory tests are nonspecific and may be normal despite serious infection [4-6]. The neutropenic patient is a diagnostic challenge as typical signs of abdominal sepsis may be masked, diagnosis may be delayed [7], and it is associated with a high mortality rate [8].


Acute Nonlocalized Abdominal Pain

Acute Nonlocalized Abdominal Pain. It is important to note that this overview of imaging focuses on the evaluation of patients with nonspecific abdominal pain, with or without fever, abdominal pain in the setting of recent surgery, and immunocompromised patients with acute abdominal pain. In addition, unless otherwise stated, the ratings and recommendations for this document specifically relate to the adult nonpregnant patient, although the narrative briefly discusses some imaging approaches for younger and pregnant patients in Variant 4. Refer to other Appropriateness Criteria topics


Acute Nonlocalized Abdominal Pain

Acute Nonlocalized Abdominal Pain. aLahey Hospital and Medical Center, Burlington, Massachusetts. bMallinckrodt Institute of Radiology, Saint Louis, Missouri. cResearch Author, Lahey Hospital and Medical Center, Burlington, Massachusetts. dPanel Chair, University of Wisconsin Hospital & Clinics, Madison, Wisconsin. eGeorgetown University Hospital, Washington, District of Columbia; American College of Surgeons. fThe University of South Florida Morsani College of Medicine, Tampa, Florida. gUniversity of Texas McGovern Medical School, Houston, Texas; American Gastroenterological Association. hNewton-Wellesley Hospital, Newton, Massachusetts. iVirginia Tech Carilion School of Medicine, Roanoke, Virginia. jMassachusetts General Hospital, Boston, Massachusetts. kUniversity of Virginia Health System, Charlottesville, Virginia. lMedstar Georgetown University Hospital, Washington, District of Columbia. mDuke University Medical Center, Durham, North Carolina. nEmory University, Atlanta, Georgia. oThe Warren Alpert School of Medicine at Brown University, Providence, Rhode Island. pPenn State Health, Hershey, Pennsylvania. qBeth Israel Deaconess Medical Center, Boston, Massachusetts. rUniversity of California San Francisco, San Francisco, California. sSpecialty Chair, Virginia Commonwealth University Medical Center, Richmond, Virginia.


Acute Nonlocalized Abdominal Pain

Acute Nonlocalized Abdominal Pain. 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.


Acute Nonlocalized Abdominal Pain

Acute Nonlocalized Abdominal Pain. Reprint requests to: publications@acr.org


Acute Nonlocalized Abdominal Pain

Acute Nonlocalized Abdominal Pain

Acute Nonlocalized Abdominal Pain. Acute Nonlocalized Abdominal Pain


Acute Nonlocalized Abdominal Pain

Acute Nonlocalized Abdominal Pain. Discussion of Procedures by Variant Variant 1: Acute nonlocalized abdominal pain and fever. No recent surgery. Initial imaging. Patients suspected of having abdominal abscesses may present in a number of ways: with fever, with diffuse or localized abdominal pain, or with a history of a condition that may predispose to abdominal abscesses, such as appendicitis, diverticulitis, inflammatory bowel disease, pancreatitis, etc. In addition, some malignant conditions (including lymphoma and necrotizing masses), as well as masses producing secondary infections, such as cholangitis in the setting of a pancreatic malignancy, could all present with abdominal pain and fever.


Acute Nonlocalized Abdominal Pain

Acute Nonlocalized Abdominal Pain. Radiography Abdomen Although the use of radiographs has shown high sensitivity (90%) for detecting intra-abdominal foreign bodies and moderate sensitivity for detecting bowel obstruction (49%), its low sensitivity for sources of abdominal pain and fever or abscess limit its role in this setting [15]. Radiography demonstrates low overall sensitivity in the detection of colitidies and enteritidies, and even low-dose CT demonstrates superior diagnostic yield in comparison with abdominal radiography [16]. Many authors suggest that they have a limited role in the evaluation of nontraumatic abdominal pain in adults [17-22].


Acute Nonlocalized Abdominal Pain

Acute Nonlocalized Abdominal Pain. Fluoroscopy Contrast Enema No current literature supports the use of contrast enema for evaluating patients with nontraumatic abdominal pain and fever in the absence of recent surgery.


Acute Nonlocalized Abdominal Pain

Acute Nonlocalized Abdominal Pain. Fluoroscopy Upper GI with SBFT No current literature supports the use of an upper GI series with small bowel follow-through (SBFT) for evaluating patients with abdominal pain and fever in the absence of recent surgery.


Acute Nonlocalized Abdominal Pain

Acute Nonlocalized Abdominal Pain. CT Abdomen and Pelvis With a generally broad differential and need for fast imaging because of clinical acuity, CT is a preferred imaging option [23]. CT can be performed without and/or with intravenous (IV) contrast and with or without positive oral contrast. Most commonly, in the setting of nonlocalized, nontraumatic abdominal pain, a routine CT of the abdomen and pelvis is performed with IV contrast and a single postcontrast phase. In this setting, precontrast and postcontrast images are not required for diagnosis. Abdominal CT without the use of oral or IV contrast has been advocated as an alternative to abdominal radiographs for evaluating appendicitis [17,24]. However, the use of IV contrast increases the spectrum of detectable pathology in patients with nonlocalized pain [25,26]. Many institutions do not routinely use oral contrast because of the associated delay in scan acquisition and departmental throughput balanced against questionable diagnostic advantage [27-30]. Contraindications are not considered in the appropriateness assessment.


Acute Nonlocalized Abdominal Pain

Acute Nonlocalized Abdominal Pain. Although sensitivity and specificity ranges are not routinely reported because of the wide spectrum of pathology encountered, there are sufficient data to suggest that CT with IV contrast adds diagnostic value and helps direct management. In a prospective study assessing impact of CT on management decisions in the ED, a total of 584 patients presented with nontraumatic abdominal complaints and CT changed leading diagnosis in 49%, changed admission status in 24%, and altered surgical plans in 25% [31]. In the same study, with concerns to etiologies associated with fever, the diagnosis of abscess decreased by 19% following CT, colitis and inflammatory bowel disease decreased by 12%, diagnosis of cholecystitis and cholangitis increased by 100%, and diagnosis of pelvic inflammatory disease increased by 280% following CT. Among intensive care unit patients with sepsis of unknown origin, CT of the abdomen and pelvis revealed the source of sepsis in 7 of 45 patients [32]. Pseudomembranous (ie, clostridium difficile) colitis is frequently encountered in the inpatient setting and is a common diagnostic consideration in a patient with fever; CT findings are present in the colon in 88% of cases [33]. Rarely, diffuse tumors such as lymphomas or metastases may present with abdominal pain and fever; CT with contrast will depict all abdominal organs and lymph node chains in the evaluation of potential malignancy.


Acute Nonlocalized Abdominal Pain

Acute Nonlocalized Abdominal Pain. Acute Nonlocalized Abdominal Pain In addition to detection of an abscess, CT can also be used as guidance for percutaneous drainage. Percutaneous drainage is feasible and effective for the treatment of abdominopelvic abscess [34].


Acute Nonlocalized Abdominal Pain

Acute Nonlocalized Abdominal Pain. MRI Abdomen and Pelvis MRI is often performed with specific indications in mind, using tailored protocols. However, when optimized for the acute setting, MRI can be an accurate examination for detecting abdominal and pelvic abscesses [35]. A prospective study of consecutive patients presenting with acute abdominal pain investigated the use of a rapid acquisition noncontrast MRI protocol for determining the source of abdominal pathology [36]. The MRI was positive in 116 of 349 cases and indeterminate in 3 cases. Overall accuracy was 99% and only 3 cases with negative MRIs later required appendectomies. A range of pathologies were detected, including SBO, diverticulitis, pelvic inflammatory disease, pyelonephritis, renal abscess, pseudomembranous colitis, and diverticular abscess. A rapid MRI protocol may be beneficial in this setting. In a separate retrospective study of MRI with IV contrast in patients with pelvic pain, MRI depicted acute appendicitis with 100% sensitivity and 92% positive predictive value and ovarian torsion with a sensitivity of 86% and specificity of 100% [37]. Given its accuracy for a range of intra-abdominal pathologies [36,37], as well as the feasibility of distinguishing infected from noninfected fluid [38], MRI may be used as an alternative to CT. It should be noted that, in practice, the feasibility of MRI for acute abdominal pain will rely on institutional expertise, availability, and adoption of protocols that are aimed at rapid acquisition and multiorgan assessment, such as that used in the study by Byott and Harris [36].


Acute Nonlocalized Abdominal Pain

Acute Nonlocalized Abdominal Pain. US Abdomen Ultrasound (US) in general is less sensitive and specific than CT for nonlocalized abdominal pain workup. One retrospective review of 92 patients who underwent multiple studies to specifically evaluate for an intra-abdominal abscess demonstrated a sensitivity and specificity for US of 75% and 91%, respectively, compared to 88% and 93%, respectively, for CT [39]. A smaller retrospective study evaluating the performance of US in patients who had initially undergone multidetector CT interpreted by experienced readers showed that CT was 100% sensitive in the detection of tubo-ovarian abscesses (n = 9), and performing a follow-up US did not aid in diagnosis [40]. Although not specifically performed to evaluate for abscesses, a large prospective study evaluating the usefulness of CT and US in patients presenting with abdominal pain (n = 1,021) showed better sensitivity with CT in diagnosis of appendicitis (94% versus 76%, P < .01) and diverticulitis (81% versus 61%, P = .048) [41]. US and CT had similar sensitivities for the detection of acute cholecystitis.


Acute Nonlocalized Abdominal Pain

Acute Nonlocalized Abdominal Pain. FDG-PET/CT Skull Base to Mid-Thigh Although generally not the primary modality of choice in the setting of acute or emergent abdominal pain, nuclear medicine studies could be used as an adjunct to inconclusive cross-sectional imaging. Because of its whole body imaging and sensitivity for infectious, inflammatory, and neoplastic processes, PET using the tracer fluorine-18- 2-fluoro-2-deoxy-D-glucose (FDG)/CT is useful in the setting of nonlocalized fevers of unknown origin, particularly if previous cross-sectional imaging did not yielded a source [42]. Nevertheless, there are no recent studies evaluating its use when patients present with symptoms localizing to the abdomen.


Acute Nonlocalized Abdominal Pain

Acute Nonlocalized Abdominal Pain. Variant 2: Acute nonlocalized abdominal pain and fever. Postoperative patient. Initial imaging. In the setting of recent abdominal surgery, a variety of conditions could produce abdominal pain, including postoperative fluid collections, hemorrhage, vascular injuries, intestinal ileus, omental torsion/infarction, etc. However, the presence of concomitant fever is primarily concerning for a postoperative abscess and warrants cross-sectional imaging for further evaluation. In addition, patients who have had recent bowel manipulation or


Acute Nonlocalized Abdominal Pain

Acute Nonlocalized Abdominal Pain


Acute Nonlocalized Abdominal Pain

Acute Nonlocalized Abdominal Pain. resection could present with similar symptoms in the setting of postoperative visceral injury and/or anastomotic leaks. In this scenario, particular emphasis is often placed on ascertaining the integrity of an anastomosis, most often using CT with positive oral and IV contrast and/or fluoroscopic studies.


Acute Nonlocalized Abdominal Pain

Acute Nonlocalized Abdominal Pain. Radiography Abdomen There are no recent studies evaluating the use of radiographs in the setting of nonlocalized abdominal pain and fever in the postoperative patient, and its role is limited in the detection of abscesses. Although it has been shown to have high sensitivity (90%) for detecting intra-abdominal foreign bodies and moderate sensitivity for detecting bowel obstruction (49%), it has low sensitivity for sources of abdominal pain and fever or abscess, which limits its role in this setting [15]. If there is concern for retained surgical instrument or sponge, a radiograph may be useful in this population because of the classic appearance of surgical sponge markers on radiographs.


Acute Nonlocalized Abdominal Pain

Acute Nonlocalized Abdominal Pain. Fluoroscopy Although limited in the detection of abscesses, fluoroscopic examinations are useful in the evaluation of some intestinal postoperative leaks, particularly when there are equivocal findings on CT [47]. Fluoroscopic examinations can be augmented or complemented by the use of CT with positive oral contrast in the evaluation of a potential leak, as discussed below. CT has the added advantage of allowing for abscess drainage should nonoperative or endoscopic management be pursued in the setting of postoperative leaks.


Acute Nonlocalized Abdominal Pain

Acute Nonlocalized Abdominal Pain. Fluoroscopy Contrast Enema In the setting of recent colorectal anastomoses, one study demonstrated that water-soluble enemas may have better sensitivity for detecting distal anastomotic leaks than CT, but neither was sensitive for a leak if the patient had a proximal colonic anastomosis [47].


Acute Nonlocalized Abdominal Pain

Acute Nonlocalized Abdominal Pain. Fluoroscopy Upper GI with SBFT The sensitivity of upper GI contrast examinations for detecting leaks after bariatric surgery varies among reports between 22% to 79% [48-51].


Acute Nonlocalized Abdominal Pain

Acute Nonlocalized Abdominal Pain. CT Abdomen and Pelvis CT of the abdomen and pelvis with IV contrast is often the first study and generally considered to be an optimal imaging modality for the evaluation of pain and suspected abscess in the postoperative patient. One study assessing the use of positive oral and IV contrast-enhanced CT scans obtained in all patients with suspected abscesses between 3 and 30 days demonstrated a similar diagnostic yield regardless of whether the scan was performed in the first postoperative week or later [23]. However, it is important to recognize that clinical suspicion can impact diagnostic yield. A retrospective study looking at postoperative patients after colorectal resection revealed that nearly 75% of patients with clinical concern for an infection will have a fluid collection, but many of these will not represent abscesses. Of the clinical, laboratory, and radiologic parameters studied, only a high index of clinical suspicion and close proximity of the fluid collection to the site of surgery were associated with predicting an infected collection [52]. In a retrospective review of elective pancreatic resections, intra- abdominal infections were diagnosed at a mean of 11.8 days following the procedure; notably, abdominal pain and peritonitis were uncommon presentations and early postoperative CT was encouraged in any patient presenting with fever and sepsis [53].


Acute Nonlocalized Abdominal Pain

Acute Nonlocalized Abdominal Pain. In the setting of colorectal anastomoses, one study evaluating 36 patients with proven leaks demonstrated water- soluble enema may have better sensitivity for detecting distal anastomotic leaks than CT (88% versus 12%, P <.001), but in a very small number of patients (n = 10) neither was sensitive for a leak if the patient had a proximal colonic anastomosis [47]. CT can also help diagnose other causes of postoperative abdominal pain, including omental infarction or torsion [54]. Although IV contrast can help define and characterize postoperative fluid collections, in patients with severe renal insufficiency CT without IV contrast, but with positive oral


Acute Nonlocalized Abdominal Pain

Acute Nonlocalized Abdominal Pain. Acute Nonlocalized Abdominal Pain contrast, it can be used as a substitute to screen for fluid collections and anastomotic leaks. Similarly, in patients with recent renal or liver transplantation in whom IV contrast cannot be administered, CT with oral contrast can be used to evaluate for intra-abdominal abscesses. CT with and without IV contrast typically is not necessary for this indication. Contraindications are not considered in the appropriateness assessment.


Acute Nonlocalized Abdominal Pain

Acute Nonlocalized Abdominal Pain. MRI Abdomen and Pelvis There are no recent studies evaluating the use of MRI in the setting of nonlocalized abdominal pain and fever in the postoperative patient. CT is most commonly performed; however, MRI can be an accurate examination for detecting abdominal and pelvic abscesses when the image acquisition is optimized [35]. Although not specifically performed in postoperative patients, a retrospective review of 29 patients with known abscesses who underwent MRI admixed with 29 patients with simple noninfected ascites, MRI demonstrated 100% accuracy for 2 observers in the detection of abdominal abscesses in examinations performed with standard T2-weighted and postcontrast T1-weighted sequences. Interestingly, there were similar sensitivities for 2 observers when the images were reviewed with only T2-weighted and diffusion-weighted imaging (100% for observer 1, and 96.6% for observer 2), demonstrating the feasibility to detect and discriminate infected from noninfected fluid on noncontrast MRI [38]. In addition to appendicitis detection, in the retrospective study by Singh et al [37], the authors were able to detect 5 abscesses (2 tubo-ovarian abscesses) in female patients who underwent MRI presenting with acute pelvic pain. In their prospective evaluation of noncontrast, rapid acquisition half-Fourier acquisition single-shot turbo spin-echo MRI in patients presenting with acute abdominal pain, Byott and Harris [36] demonstrated an overall accuracy of 99% (463 of 468 patients), including detection of diverticular and renal abscesses.


Acute Nonlocalized Abdominal Pain

Acute Nonlocalized Abdominal Pain. The accuracy of MRI in detecting anastomotic leaks has not been studied.


Acute Nonlocalized Abdominal Pain

Acute Nonlocalized Abdominal Pain. FDG-PET/CT Skull Base to Mid-Thigh There are limited recent studies evaluating the use of nuclear medicine imaging in the setting of nonlocalized abdominal pain and fever in the postoperative patient. FDG-PET/CT is useful in the workup of nonlocalized fevers of unknown origin, but in the setting of recent abdominal or pelvic surgery, normal postoperative inflammation could lead to false-positive results. As such, FDG-PET/CT could be used in a complementary fashion to other imaging studies when correlated with relevant surgical and clinical information and when other imaging studies are negative or inconclusive [42].


Acute Nonlocalized Abdominal Pain

Acute Nonlocalized Abdominal Pain. Nuclear Medicine Older studies performed in the 1980s to 1990s suggested gallium scans and indium and technetium leukocyte scans are useful in evaluating abdominal infections and abscesses when the CT scan is negative or equivocal [43- 45]. However, it is important to recognize that CT technology has significantly advanced since these studies were published. Older literature on technetium-labeled leukocytes also suggested a very high sensitivity and specificity for abdominal abscesses as well, although there are no adequate recent comparisons with CT [46]. In the setting of recent hepatobiliary surgery and specific concern for biliary ductal injury, cholescintigraphy can confirm the presence of a bile leak.


Acute Nonlocalized Abdominal Pain

Acute Nonlocalized Abdominal Pain. Variant 3: Acute nonlocalized abdominal pain. Neutropenic patient. Initial imaging. In neutropenic patients, abdominal pain remains a diagnostic challenge because of the lack of classic clinical and laboratory signs of intra-abdominal disease [8]. Therefore, the diagnosis of acute abdomen may be delayed in these patients [7]. Neutropenia is being encountered more commonly in clinical practice and may be because of


Acute Nonlocalized Abdominal Pain

Acute Nonlocalized Abdominal Pain. Acute Nonlocalized Abdominal Pain cytotoxic chemotherapy or immunosuppressive therapy. Colitidies and enteritidies are commonly found in this patient population, including clostridium difficile colitis, cytomegalovirus colitis, graft-versus-host disease, neutropenic enterocolitis, and bowel ischemia and perforation [8,56]. One study reported the most frequent causes of abdominal pain are neutropenic enterocolitis (28%) and SBO (12%) [8]. Atypical and opportunistic infections, chemotherapeutic-related mucosal injury, and tumors can all result in bowel pathology, and are commonly approached with IV contrast-enhanced CT as the initial imaging modality.


Acute Nonlocalized Abdominal Pain

Acute Nonlocalized Abdominal Pain. Radiography Abdomen There are no recent studies that evaluate the use of radiography in the setting of acute nonlocalized or diffuse abdominal pain in the neutropenic patient. Radiography demonstrates low overall sensitivity in the detection of colitidies and enteritidies, and even low-dose CT demonstrates superior diagnostic yield in comparison with abdominal radiography [16]. Many authors suggest that radiographs have a limited role in the evaluation of nontraumatic abdominal pain in adults [17-22].


Acute Nonlocalized Abdominal Pain

Acute Nonlocalized Abdominal Pain. Fluoroscopy Contrast Enema There are no recent studies evaluating the use of contrast enema in the setting of acute nonlocalized or diffuse abdominal pain in the neutropenic patient.


Acute Nonlocalized Abdominal Pain

Acute Nonlocalized Abdominal Pain. Fluoroscopy Upper GI with SBFT There are no recent studies evaluating the use of upper GI series with SBFT in the setting of acute nonlocalized or diffuse abdominal pain in the neutropenic patient. CT is often the initial imaging study to diagnose small bowel pathology in the immunocompromised patient, but occasionally barium studies may offer additional complementary information when mucosal lesions are small.


Acute Nonlocalized Abdominal Pain

Acute Nonlocalized Abdominal Pain. CT Abdomen and Pelvis CT with IV contrast is extremely useful in the evaluation of the neutropenic patient with abdominal pain secondary to its high spatial resolution and ability to display key imaging features [57]. Infectious and inflammatory processes of the small bowel and colon are well depicted by CT with IV contrast, which offers the additional advantage of depicting abscesses or perforations. Given the frequency of neutropenic enterocolitis (28%) and SBO (12%) in this setting, and as neutropenic enterocolitis is largely managed nonsurgically, an early and accurate diagnosis with CT can avoid unnecessary surgery and initiate appropriate medical management [8]. In addition, other abdominal infections, chemotherapeutic-related mucosal injury, and visceral tumors may be depicted by CT. CT without IV but with positive oral contrast can be used as an alternative if patients have severe renal insufficiency or a history of iodinated contrast allergies. Contraindications are not considered in the appropriateness assessment. Multiphasic CT imaging offers little additional benefit in absence of specific clinical indications related to liver or kidneys.


Acute Nonlocalized Abdominal Pain

Acute Nonlocalized Abdominal Pain. MRI Abdomen and Pelvis There are no recent studies available to evaluate the use of MRI in acute nonlocalized or diffuse abdominal pain in the neutropenic patient. Although MRI with contrast may be used to evaluate SBO [58], there are no studies available to evaluate its diagnostic accuracy for neutropenic enterocolitis or other common colitidies or enteritidies in the neutropenic patient. MRI with contrast offers high soft-tissue contrast and the ability to administer gadolinium in patients with a history of allergic reaction to iodinated contrast material [58]. Specialized protocols (MR enterography or colonography) exist to interrogate the small bowel and colon and are mostly designed for use in patients with history of inflammatory bowel disease in the nonemergent setting. For clinically stable patients who are not able to undergo CT and in whom the bowel is a primary diagnostic consideration, MRI without and with contrast (and in particular MR enterography) may be an alternative imaging option.


Acute Nonlocalized Abdominal Pain

Acute Nonlocalized Abdominal Pain. US Abdomen There are no recent studies available for the evaluation of US in the setting of acute nonlocalized abdominal pain in the neutropenic patient. US may serve as a fast way of evaluating the liver, kidneys, and biliary tree, including the evaluation of HIV cholangiopathy. In the HIV-infected patient presenting with prolonged fever, one study demonstrated abdominal US successfully identifies liver lesions and splenic microabscesses in 14% of the presenting population [59].


Acute Nonlocalized Abdominal Pain

Acute Nonlocalized Abdominal Pain. Nuclear Medicine and FDG-PET/CT Skull Base to Mid-Thigh There are no recent studies evaluating the use of nuclear medicine imaging in the setting of acute abdominal pain in the neutropenic patient, and there are no specific indications for its use in this setting. Because of its whole


Acute Nonlocalized Abdominal Pain

Acute Nonlocalized Abdominal Pain

Acute Nonlocalized Abdominal Pain. Acute Nonlocalized Abdominal Pain


Acute Nonlocalized Abdominal Pain

Acute Nonlocalized Abdominal Pain. Variant 4: Acute nonlocalized abdominal pain. Not otherwise specified. Initial imaging. The causes of nonlocalized, nontraumatic abdominal pain are extensive, and, as such, imaging needs to be broad enough to visualize the entire abdomen and pelvis, screening for visceral, solid organ, and vascular abnormalities. Imaging strategies are similar to those in patients who have concomitant fever, as many of the sources of pain overlap. CT is frequently performed first.


Acute Nonlocalized Abdominal Pain

Acute Nonlocalized Abdominal Pain. Fluoroscopy Contrast Enema There are no recent studies evaluating the use of contrast enema imaging in the setting of nonlocalized abdominal pain, and there are no specific indications for its use in this setting. Endoscopy is the preferred initial examination of the stomach and colon in patients suspected of having inflammatory bowel disease.


Acute Nonlocalized Abdominal Pain

Acute Nonlocalized Abdominal Pain. CT Abdomen and Pelvis CT can be performed without and/or with IV contrast and with or without oral contrast, depending on localizing symptoms and/or laboratory findings. In general, a single-phase IV contrast-enhanced examination is performed as additional precontrast and postcontrast images are not required for diagnosis. Abdominal CT without the use of oral or IV contrast has been advocated as an alternative to abdominal radiographs for evaluating appendicitis [17,24]. However, the use of IV contrast increases the spectrum of detectable pathology [25,26]. Unless otherwise specified, the subsequent discussion of CT refers to IV contrast-enhanced CT. Contraindications are not considered in the appropriateness assessment.


Acute Nonlocalized Abdominal Pain

Acute Nonlocalized Abdominal Pain. Many institutions no longer routinely use oral contrast because of the associated delay in scan acquisition and departmental and ED throughput balanced against questionable diagnostic advantage [27-30]. Positive oral contrast may help improve confidence in identifying bowel-related pathology; however, advances in CT technology with multiplanar reformations can also improve diagnostic confidence in patients with abdominal pain [61-63].


Acute Nonlocalized Abdominal Pain

Acute Nonlocalized Abdominal Pain. Several studies have shown that CT improves the final diagnosis and management of patients who present with abdominal pain [5,24,31,64-67]. A prospective trial of 547 patients presenting to the ED with abdominal pain demonstrated that CT altered the diagnosis in 54% of patients and frequently changed disposition patterns, with a greater proportion of patients discharged in lieu of admission for observation [68]. Other studies have shown that CT outperforms clinical diagnosis [69,70]. Additionally, the use of CT in patients with acute abdominal pain


Acute Nonlocalized Abdominal Pain

Acute Nonlocalized Abdominal Pain. In a prospective study of 584 ED patients presenting with nontraumatic abdominal pain, CT was shown to change the diagnosis, improve diagnostic certainty, and affect potential patient management decisions [31]. In this study, CT was used to alter the leading diagnosis in 49% of the patients and increase mean physician diagnostic certainty from 70.5% (pre-CT) to 92.2% (post-CT). The management plan was changed by CT in 42% of the patients. In another study of 522 young adult patients presenting to the ED with abdominal pain, no laboratory test was sufficient to offer reassurance that a CT was not necessary [72]. One retrospective study evaluating 333 ED patients with acute abdominal pain and an abdominal CT demonstrated no significant difference in accuracy if the radiologist was blinded to relevant clinical or laboratory information (approximately 85%) [73]. CT is highly accurate in determining the site of visceral perforation, particularly in the setting of upper intestinal perforation, which could impact the surgical approach [74].


Acute Nonlocalized Abdominal Pain

Acute Nonlocalized Abdominal Pain. With an aging United States population and the relatively high frequency of ED presentations for acute abdominal pain, multiple recent studies have looked at the imaging evaluation of elderly patients, particularly the range of diagnoses and the use of abdominal CT. Depending on the article, elderly is defined as ranging from >65 years of age to >80 years of age. In this subset of the population, many laboratory tests are nonspecific and may be normal despite serious abnormalities [4-6]. Many authors advocate for liberal use of CT in elderly patients [4,75,76]. The most common causes of abdominal pain in elderly patients undergoing a CT examination are different than those in younger patients. One retrospective study looked at the use of CT in 464 patients >80 years of age and found the most common diagnoses were SBO (18%), diverticulitis (9%), nonischemic vascular emergencies including abdominal aortic aneurysm and dissection (6%), bowel ischemia (4%), appendicitis (3%), and colonic obstruction (2%). These diagnoses were clinically unsuspected in 43% of patients [4]. Another study evaluating the incidence of acute mesenteric ischemia in patients >75 years of age demonstrated a high age-specific incidence in this population, with a greater incidence of acute mesenteric ischemia than acute appendicitis or ruptured abdominal aortic aneurysms. These patients often have a nonspecific presentation and authors suggest use of dual-phase (arterial and portal venous phase) CT with contrast to ensure adequate evaluation of mesenteric vasculature in all patients >75 years of age presenting with acute abdominal pain [75].


Acute Nonlocalized Abdominal Pain

Acute Nonlocalized Abdominal Pain. Acute Nonlocalized Abdominal Pain MRI Abdomen and Pelvis MRI has been shown to provide clinically useful information for rapid diagnosis of acute bowel pathology [35,58,84,85] and the following gynecological emergencies: ovarian hemorrhage, ectopic pregnancy, tumor rupture, torsion, hemorrhage, infarction, and pelvic inflammatory disease [36,86,87]. Although MRI has longer acquisition times relative to CT, improvements in technology combined with tailored abdominal protocols could be performed in 10 minutes or less [36,88]. One prospective study looking at the use of noncontrast MRI in 468 patients with acute abdominal pain (excluding renal colic), with an image acquisition time of under 2 minutes, showed an overall accuracy of 99% in diagnosing diseases ranging from acute bowel inflammation, obstruction, and pancreaticobiliary diseases, to renal inflammation and gynecological processes [36]. In the setting of acute pelvic pain, MRI with contrast can accurately diagnose acute appendicitis, ovarian torsion, and other adnexal diseases [37]. Because useful information can be obtained without contrast, MRI, when available, has been shown to be a reliable next step following US in the imaging of pregnant patients [89]. MRI is becoming a favored, invaluable problem-solving modality used in the imaging of pregnant patients because it avoids many of the drawbacks of US and CT. The ratings of MRI for this variant presume the patient is not pregnant.


Acute Nonlocalized Abdominal Pain

Acute Nonlocalized Abdominal Pain. US Abdomen US can be used to screen the abdomen for sources of abdominal pain. In the nonpregnant adult patient, it has been suggested that obtaining a US followed by CT in patients with negative or inconclusive results offers the best sensitivity for disease [60]. In addition, US may be useful in selected localizing conditions, including cholecystitis, cholangitis, liver abscess, diverticulitis, appendicitis, and small-bowel inflammation, where it may be used to assess activity of Crohn disease [41,90-93]. Although not frequently used for this indication, some small studies suggest US maybe more sensitive and specific than abdominal radiographs in the diagnosis of suspected SBOs and can have a similar sensitivity to CT in specialized centers [41,94]. Although US may be able to depict portions of an abscess or malignancy (such as lymphoma), it is not optimized to view many areas of the abdomen, particularly in the presence of increased bowel gas or free intraperitoneal air. In spite of these shortcomings, US may be useful in this setting in the initial imaging of younger patients [60].


Acute Nonlocalized Abdominal Pain

Acute Nonlocalized Abdominal Pain. Although there are references that report on studies with design limitations, 18 well-designed or good-quality studies provide good evidence.


Acute Nonlocalized Abdominal Pain

Acute Nonlocalized Abdominal Pain


Acute Nonlocalized Abdominal Pain

Acute Nonlocalized Abdominal Pain. Supporting Documents For additional information on the Appropriateness Criteria methodology and other supporting documents go to www.acr.org/ac.