Distinguishing clinical and imaging features of nodular regenerative hyperplasia and large regenerative nodules of the liver.

AIM: Nodular regenerative hyperplasia (NRH) and large regenerative nodules (LRN) are distinct types of hepatocellular nodules that have been confused in the radiology literature. However, distinction is critical because their clinical significance is quite different. Our purpose was to review the clinical and imaging findings in a series of patients with NRH and LRN in order to identify distinguishing clinical and imaging features. MATERIALS AND METHODS: This was a retrospective case series. The clinical and imaging features were compared in 36 patients with pathological proof of NRH and 23 patients with pathological evidence of LRN. RESULTS: NRH and LRN have different predisposing factors and imaging findings. NRH is often associated with organ transplantation, myeloproliferative disease, or autoimmune processes. Livers with NRH typically do not have enhancing nodules; none of the present patients with NRH had enhancing liver masses. In contrast, LRN are often associated with Budd-Chiari syndrome. Enhancing liver masses were noted in 19 (83%) of the 23 patients with LRN. The p values for the comparisons were less than 0.001 for both enhancing liver masses and hepatic vein thrombosis. CONCLUSION: NRH and LRN can have distinct clinical presentations and imaging appearances. LRN often result in enhancing liver nodules, whereas NRH usually does not. Clinical and imaging information enables the distinction of LRN and NRH in many cases.

Focal nodular hyperplasia: typical and atypical MRI findings with emphasis on the use of contrast media.

Focal nodular hyperplasia is a benign hypervascular hepatic tumour, frequently detected in asymptomatic patients undergoing imaging studies for unrelated reasons. Magnetic resonance imaging (MRI) generally allows a confident differential diagnosis with other hypervascular liver lesions, either benign or malignant. In addition, due to the recent development of hepatospecific MRI contrast agents, MRI concomitantly enables functional and morphological information to be obtained, thus providing important clues for the detection and characterization of focal nodular hyperplasia lesions.

Hepatic capsular retraction: spectrum of benign and malignant etiologies.

Retraction of the liver capsule may be associated with a diverse spectrum of benign and malignant hepatic abnormalities. These include primary malignant neoplasms (epithelioid hemangioendothelioma, hepatocellular carcinoma, cholangiocarcinoma), secondary malignant neoplasms before and after treatment, and hepatic hemangioma, especially in cirrhotic livers. Other etiologies include confluent fibrosis in cirrhotic livers, chronic biliary obstruction (as can be seen in primary sclerosing cholangitis), and traumatic hepatic injury (iatrogenic and noniatrogenic). Because several recent studies have incorrectly reported hepatic capsular retraction as a specific sign of hepatic malignancy, it is important to understand the imaging appearances of the various etiologies associated with this sign to avoid misdiagnosis that may adversely affect the therapeutic approach.

Acute fulminant hepatic infection causing fatal "emphysematous hepatitis": case report.

We describe a case of fatal fulminant hepatic infection with gas replacement of the hepatic parenchyma and no evidence of a liquified abscess in a diabetic patient: a case of "emphysematous hepatitis," the hepatic equivalent of emphysematous pyelonephritis. Computed tomography and clinical findings are described.

Radiologist performance in the diagnosis of internal hernia by using specific CT findings with emphasis on transmesenteric hernia.

PURPOSE: To evaluate the performance of radiologists in the diagnosis of internal hernia with specific computed tomographic (CT) findings. MATERIALS AND METHODS: Abdominal CT scans obtained in 42 patients were retrospectively reviewed by three radiologists. The case group consisted of 18 patients with internal hernias (two paraduodenal, 16 transmesenteric); the comparison group was 24 patients with no internal hernia. Images were reviewed in a random and blinded fashion. Individual and group performance was evaluated with receiver operating characteristic (ROC) analysis, and interobserver agreement was measured with Cronbach coefficient alpha. Individual CT signs relevant as predictors of transmesenteric hernia were identified with logistic regression analysis and ranked by their odds ratio and P values. RESULTS: Both paraduodenal hernias were diagnosed by all readers on the basis of CT signs, including a retrogastric saclike mass of small-bowel loops. Diagnosis of transmesenteric hernia was more difficult and variable, with an average accuracy of area under the ROC curve (A(z)) of 77%, sensitivity of 63%, and specificity of 76%. CT signs of transmesenteric hernia were recognized consistently (Cronbach coefficient alpha >or= 0.80) and included a cluster of dilated small-bowel segments and stretching and displacement of mesenteric vessels. Coexisting volvulus and ischemia were diagnosed with low sensitivity (46% and 43%, respectively) but high specificity (96% and 98%, respectively). CONCLUSION: Diagnosis of internal hernia with CT remains difficult. Special attention should be given to the clustering of bowel loops, the mesenteric vessels, and signs of small-bowel obstruction.

Focal nodular hyperplasia: morphologic and functional information from MR imaging with gadobenate dimeglumine.

PURPOSE: To determine whether gadobenate dimeglumine (Gd-BOPTA) is able to provide morphologic and functional information for characterization of focal nodular hyperplasia (FNH). MATERIALS AND METHODS: Sixty-three consecutive patients with proved FNH were retrospectively examined. Magnetic resonance (MR) imaging with T2-weighted turbo spin-echo and T1-weighted gradient-echo sequences was performed. Images were acquired prior to and during the dynamic phase of contrast-material enhancement and 1-3 hours after administration of 0.1 mmol/kg Gd-BOPTA. Qualitative analysis of signal intensity and homogeneity on images in the various phases of the MR study and examination for the presence of central scar or atypical features were performed. On the basis of features observed in the precontrast and dynamic phases, lesions were defined as typical or atypical. Intensity and enhancement patterns of the lesions and scars were also evaluated in the delayed phase. RESULTS: One hundred FNHs were depicted on MR images. Seventy-nine of 100 lesions demonstrated typical morphologic and enhancement characteristics. On delayed phase images, 72% of 100 FNHs appeared hyperintense; 21%, isointense; and 7%, slightly hypointense. The delayed pattern of enhancement was homogeneous, heterogeneous, and peripheral in 58%, 22%, and 20% of 100 FNHs, respectively. Atypical morphologic features and lesion and/or scar enhancement were observed in 21 of 100 FNHs. On delayed phase images, 76% of 100 atypical FNHs appeared hyperintense, 14% isointense, and 10% slightly hypointense. Hyperintensity and isointensity allowed the correct characterization in 90% of atypical FNHs. CONCLUSION: Gd-BOPTA during both dynamic and delayed phases provides morphologic and functional information for the characterization of FNH.

Using CT and cholangiography to diagnose biliary tract carcinoma complicating primary sclerosing cholangitis.

OBJECTIVE: The objective of our study was to determine the value of CT and cholangiography for diagnosing biliary tract carcinoma complicating primary sclerosing cholangitis. MATERIALS AND METHODS: One hundred thirteen abdominal CT examinations and cholangiograms in 45 patients with primary sclerosing cholangitis, including 18 patients with established biliary tract carcinoma, were analyzed for tumor. Four radiologists who were unaware of the presence or absence of carcinoma rated each study as to the probability of malignancy. Receiver operating characteristic curve analysis was used to assess the diagnostic performance of CT and cholangiography, the value of imaging signs, and the degree of inter-observer variation in interpretation. Sensitivity and specificity values were calculated. RESULTS: CT outperformed cholangiography in the detection of carcinoma. The average area under the receiver operating characteristic curve was 0.82 for CT and 0.57 for cholangiography (p = 0.003). Sensitivity and specificity for detecting carcinoma using CT were good, with average values of 82% and 80%, respectively. Average sensitivity and specificity for cholangiography were 54% and 53%, respectively. The most reliable sign of tumor on CT was a discrete mass. Progressive biliary dilatation on sequential studies was the most useful sign on cholangiography. Interobserver agreement assessed using the Cronbach alpha was fair for cholangiography and good for CT. CONCLUSION: CT provides good sensitivity and specificity and significantly outperforms cholangiography in detecting biliary tract carcinoma complicating primary sclerosing cholangitis. Despite limitations, CT and cholangiography provide useful information not otherwise available in the treatment of patients with primary sclerosing cholangitis.

Portal venous thrombosis or sclerosis in liver transplantation candidates: preoperative CT findings and correlation with surgical procedure.

PURPOSE: To review computed tomographic (CT) findings in patients with surgically proved portal venous (PV) thrombosis or sclerosis and to correlate these findings with the surgical procedure used at orthotopic liver transplantation (OLT). MATERIALS AND METHODS: Among 379 OLTs, PV thrombosis or sclerosis was found at surgery in 39 patients (10.3%). Before OLT, surgical records and CT images were retrospectively reviewed in 35 patients with available CT studies. Diameter of the extrahepatic PV and patency of the PV system were evaluated. Cavernous transformation, calcifications of the venous wall or thrombus, lesions suggestive of tumor, mesenteric varices, edema, or splenorenal shunt were recorded. A nonpaired Student t test and the Fisher exact test were used to analyze the results. RESULTS: Of 35 patients, 23 (66%) underwent thrombectomy with direct PV-to-PV anastomosis and 12 (34%) had placement of venous grafts or other anastomoses. The extrahepatic PV was 8.2 mm, but it significantly (P < or = .05) decreased in patients with splenorenal shunt. In 30 patients, CT depicted thrombosis, PV calcification, or other abnormalities. The thrombus extended to or beyond the confluence of the splenic and superior mesenteric veins in 21 (60%) and 11 (31%) patients, respectively. Eleven patients (31%) had cavernous transformation of the PV; eight (23%), a cordlike sclerotic PV; 19 (54%), a splenorenal shunt; 11 (31%), PV calcification; 17 (49%), mesenteric edema; 14 (40%), mesenteric varices. Patients with a cordlike or calcified PV were significantly (P < or = .05) more likely to require modification of the surgical technique. CONCLUSION: Before OLT, CT can aid in assessment of PV and associated findings and in surgical management.

Primary biliary cirrhosis: clinical, pathologic, and helical CT findings in 53 patients.

PURPOSE: To evaluate and compare clinical, pathologic, and helical computed tomographic (CT) findings of primary biliary cirrhosis (PBC). MATERIALS AND METHODS: The authors reviewed the medical records and CT scans of 53 patients who underwent evaluation, treatment, and orthotopic liver transplantation (OLT) at their institution. All patients underwent helical multiphase CT (total, 98 abdominal CT scans; range, one to five scans per patient). Multiple epidemiologic, clinical, and morphologic criteria were evaluated. Advanced disease was defined as hepatic insufficiency leading to OLT within the subsequent 2 years. Clinical and morphologic features were evaluated and compared in the advanced and less advanced cases of PBC. RESULTS: Common and characteristic findings included the following: 45 (85%) of the 53 patients were women with the onset of disease (diagnosis) in middle age (mean, 50.7 years; range, 26-71 years). The average time from diagnosis to OLT was 6.1 years (range, 1.5-20.0 years). CT findings in advanced PBC often resembled those seen in other forms of cirrhosis, with a small heterogeneously attenuating liver, varices, and splenomegaly. The liver in less advanced disease was usually enlarged or normal in size, with a smooth contour, little atrophy, and lacelike fibrosis and regenerative nodules in nearly one-third of the livers. Patients with less advanced disease frequently had varices (n = 33 [62%]) and ascites (n = 13 [24%]). Lymphadenopathy was seen in 47 (88%) patients. Hepatocellular carcinoma was found in four (8%) patients, two of whom also had chronic hepatitis C. During a follow-up period of 5-72 months (median, 46 months; mean, 42 months) after OLT, only two patients experienced recurrence of PBC. CONCLUSION: PBC is an important cause of liver failure, with distinctive clinical and CT findings that may assist diagnosis and allow adequate treatment. CT can demonstrate varices and ascites before frank cirrhosis is evident and can help evaluate the progression of the disease.

CT evaluation of the liver: principles and techniques.

Technical advances within the past decade have dramatically improved the diagnostic capabilities of CT, primarily due to helical CT scanners coupled with mechanical injectors for i.v. administration of contrast media. There is no such thing as a generic "abdominal CT scan"; rather, specific protocols should be utilized for optimal detection and characterization of hepatic masses (or other suspected pathologic processes). Multiphasic CT protocols are especially important for detecting hypervascular liver tumors. We present the principles and rationale for various CT protocols along with some of the common pitfalls. Understanding this background material will allow the reader to better understand subsequent articles dealing with specific applications of CT and other abdominal imaging techniques.

Imaging of benign hepatic masses.

Using helical CT and rapid i.v. injection of contrast material, benign hepatic masses are discovered in at least 20% of subjects. To minimize expensive and invasive evaluation, an orderly approach to the interpretation of these lesions is necessary. Many benign lesions have a near pathognomonic appearance on a properly performed and interpreted CT scan. Others can have the diagnosis confirmed by a specific and well-chosen follow-up study, such as contrast-enhanced MR. In this article we present the most common types of benign hepatic masses and our approach to their diagnosis.

Hepatic adenomas: imaging and pathologic findings.

Hepatocellular adenoma is a rare benign lesion that is most often seen in young women with a history of oral contraceptive use. It is typically solitary, although multiple lesions have been reported, particularly in patients with glycogen storage disease and liver adenomatosis. Because of the risk of hemorrhage and malignant transformation, hepatocellular adenomas must be identified and treated promptly. At pathologic analysis, hepatocellular adenoma is usually a well-circumscribed, nonlobulated lesion, and at gross examination, resected adenomas frequently demonstrate areas of hemorrhage and infarction. Most adenomas are not specifically diagnosed at ultrasonography (US) and are usually further evaluated with computed tomography (CT) or other imaging modalities. Color Doppler US may help differentiate hepatocellular adenoma from focal nodular hyperplasia. Multiphasic helical CT allows more accurate detection and characterization of focal hepatic lesions. Hepatocellular adenomas are typically bright on T1-weighted magnetic resonance images and predominantly hyperintense relative to liver on T2-weighted images. The prognosis of hepatic adenoma is not well established. Criteria that guide treatment include the number and size of the lesions, the presence of symptoms, and the surgical risk incurred by the patient. Understanding the imaging appearance of hepatocellular adenoma can help avoid misdiagnosis and facilitate prompt, effective treatment.

Discrimination of small hepatic hemangiomas from hypervascular malignant tumors smaller than 3 cm with three-phase helical CT.

PURPOSE: To compare the appearance of small hepatic hemangiomas at nonenhanced and contrast material-enhanced helical computed tomography (CT) with that of small (<3-cm) hypervascular malignant liver tumors and to evaluate the accuracy of multiphase helical CT for differentiating small hemangiomas from small hypervascular malignant tumors. MATERIALS AND METHODS: Radiologists reviewed multiphase helical CT liver images in 86 patients with 37 hemangiomas and 49 malignant liver tumors. They evaluated lesion type and degree of enhancement for change from arterial to portal venous phase. They rated their confidence in the discrimination of hemangiomas from malignant tumors. RESULTS: At arterial phase CT, enhancement similar to aortic enhancement was observed in 19%-32% of hemangiomas and 0%-2% of malignant tumors; globular enhancement, in 62%-68% and 4%-12%, respectively. At portal venous phase CT, enhancement similar to blood pool enhancement was observed in 43%-54% of hemangiomas and 4%-14% of malignant tumors; globular enhancement, in 46%-49% and 0%-2%, respectively. For all readers and all phases of enhancement, the area under the receiver operating characteristic curves was 0.81-0.87, indicating that inherent accuracy of CT is high and that there was no significant difference (P >.28) in overall accuracy. Readers diagnosed hemangiomas with 47%-53% mean sensitivity with all enhancement phases and diagnosed malignant lesions with 95% mean specificity. CONCLUSION: Small hemangiomas frequently show atypical appearances at CT. Two-phase helical CT does not improve sensitivity but does improve specificity for differentiating hemangiomas from hypervascular malignant tumors.

Hypervascular hepatocellular carcinoma: detection with double arterial phase multi-detector row helical CT.

PURPOSE: To assess whether double arterial phase imaging with multi-detector row helical computed tomography improves detection of hypervascular hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Fifty-one patients with 96 hypervascular HCCs underwent double arterial phase imaging of the entire liver. At measured delay after intravenous administration of 2 mL/kg of contrast medium at a rate of 5 mL/sec, the early and late arterial phase images were obtained serially during a single breath hold with interscan delay of 5.0 seconds. Detector row configuration of 2.5 x 4 mm, pitch of 6, and scanning time of 10.5 seconds for each phase were used. Forty 5-mm-thick reconstruction images were obtained for each phase. Each image set was interpreted separately by three observers, who were unaware of tumor burden in the liver, to detect hypervascular HCC. Sensitivity, positive predictive value, and area below the receiver operating characteristic curve (A(z)) for early and late arterial phases separately and together were calculated. RESULTS: Mean sensitivity and positive predictive value for hypervascular HCC were 54% and 85% for the early arterial phase, 78% and 83% for the late arterial phase, and 86% and 92% for the double arterial phase, respectively. Double arterial phase imaging showed significantly superior sensitivity compared with early or late arterial phase imaging alone for detecting HCC (P <.05). The mean A(z) value for double arterial phase was significantly higher than that for early or late arterial phase imaging alone (P <.05). Double arterial phase imaging showed the lowest number of false-positive lesions. CONCLUSION: Double arterial phase imaging is recommended to improve detection of hypervascular HCCs and reduce false-positive lesions.

Abdominal thrombotic and ischemic manifestations of the antiphospholipid antibody syndrome: CT findings in 42 patients.

PURPOSE: To determine the abdominal computed tomographic (CT) findings in patients with antiphospholipid antibody syndrome (APS). MATERIALS AND METHODS: Retrospective review of medical records from two university medical centers from 1994 through 1997 revealed 215 patients who had a hypercoagulable state attributed to primary or secondary APS. Abdominal CT findings in these patients were reviewed for evidence of large-vessel occlusion or visceral ischemia. RESULTS: In 42 (19.5%) of 215 patients with APS (age range, 32-65 years; mean age, 42 years), abdominal thromboses or ischemic events were detected at CT. Twenty-two (52%) had major vascular thromboses, including those in the inferior vena cava (n = 10), portal and superior mesenteric veins (n = 7), splenic vein (n = 4), and aorta (n = 1). Thirty-six (86%) patients had abdominal visceral ischemia resulting in renal infarction (n = 22), bowel ischemia (n = 13), splenic infarction (n = 6), pancreatitis (n = 3), hepatic infarction (n = 1), and/or hepatic dysfunction with portal hypertension (n = 1). In some patients, more than one abdominal organ and/or vessel was involved. CONCLUSION: Patients who have circulating antiphospholipid antibodies are at risk for major abdominal vascular thromboses and organ infarction. Radiologists must be familiar with this syndrome; they may be the first physicians to suggest the diagnosis on the basis of findings of unusual or recurrent sites of thrombosis, especially in young patients.

Focal nodular hyperplasia: CT findings with emphasis on multiphasic helical CT in 78 patients.

PURPOSE: To evaluate features of focal nodular hyperplasia (FNH) at multiphasic helical computed tomography (CT). MATERIALS AND METHODS: Clinical, pathologic, and preoperative imaging findings were retrospectively reviewed in 78 patients. Conventional liver CT was performed in nine patients; helical multiphasic CT, in 69. Diagnosis was based on complete resection (n = 20), biopsy (n = 42), or clinical and imaging follow-up for a minimum of 6 months (n = 16). Number, size, location, margins, surface, homogeneity of enhancement, and presence of a central scar, mass effect, exophytic growth, calcification, pseudocapsule, or vessels feeding or draining the lesion were evaluated. RESULTS: CT depicted 124 tumors (mean diameter, 4.1 cm; range, 1-11 cm); 62 were small (< or =3 cm). FNHs were hypervascular and hyperattenuating to liver on 106 of 106 arterial phase scans and were isoattenuating to liver on 82 of 89 delayed scans. Of the 124 tumors, 111 enhanced homogeneously, 109 had a smooth surface, 101 were subcapsular, 89 had ill-defined margins, and 62 had a central scar that was observed more often in large lesions (40 of 62 lesions) than in small lesions (22 of 62 lesions). FNHs less frequently exerted a mass effect (43 lesions), had vessels around or within the lesion (42 lesions), demonstrated exophytic growth (40 lesions), or showed a pseudocapsule (10 lesions). Only one FNH had calcification. CONCLUSION: Helical CT demonstrates characteristic features that may allow confident diagnosis of FNH. In typical cases, neither biopsy nor further imaging is necessary.

Hemangioma in the cirrhotic liver: diagnosis and natural history.

PURPOSE: To investigate the natural history and diagnosis of cavernous hemangioma in the cirrhotic liver with computed tomography (CT) and magnetic resonance (MR) imaging. MATERIALS AND METHODS: Imaging and pathologic findings of 21 hemangiomas in 17 patients were retrospectively reviewed. CT of the liver was performed in all patients; MR imaging, in four. Cirrhosis was confirmed histologically in all patients, and the diagnosis of hemangioma was based on histopathologic findings (15 patients, 18 hemangiomas) or strict imaging criteria (two patients, three hemangiomas). Ten patients underwent imaging follow-up. The number, sizes, location, attenuation, pattern of enhancement, exophytic growth, presence of capsular retraction, and size stability were evaluated. RESULTS: Of the 21 hemangiomas, five were not detected at CT or MR imaging. Twelve (75%) of 16 hemangiomas were subcapsular, two (12%) of 16 demonstrated exophytic growth, 14 (87%) of 16 demonstrated nodular peripheral enhancement, and 16 (100%) of 16 were isoattenuating to blood vessels. At MR imaging, all five hemangiomas demonstrated nodular peripheral enhancement and hyperintensity on T2-weighted images. Seven lesions were smaller at follow-up, and five lesions developed retraction of the hepatic capsule. CONCLUSION: Even within the cirrhotic liver, larger hemangiomas can usually be diagnosed confidently with CT or MR imaging. With progressive cirrhosis, however, hemangiomas are likely to decrease in size, become more fibrotic, and are difficult to diagnose radiologically and pathologically.

Bowel obstruction following liver transplantation: clinical and ct findings in 48 cases with emphasis on internal hernia.

PURPOSE: To review the incidence, cause, and radiologic findings of bowel obstruction in patients who have undergone orthotopic liver transplantation (OLT). MATERIALS AND METHODS: Retrospective review of 4,001 cases of OLT revealed 48 cases of bowel obstruction in 44 patients. Seventeen computed tomographic (CT) scans and seven barium-enhanced radiographs were reviewed to determine level and cause. Surgical proof was available in 45 cases, while three had characteristic clinical and radiographic features. RESULTS: Adhesions caused the obstruction in 19 cases in 16 patients; three had bowel ischemia. Internal hernias caused obstruction in 18 patients; all obstructions were transmesenteric or retroanastomotic and occurred with choledochoenteric anastomosis. Seven patients had volvulus; four had bowel ischemia. CT signs of internal hernia included mesenteric vascular abnormalities and clusters of dilated small-bowel segments that displaced the colon away from the abdominal wall. Prospective diagnosis of internal hernia was made in only one case. Incisional or inguinal hernia caused obstruction in seven patients; CT was used just once. Four patients had neoplastic bowel obstruction, three due to posttransplantation lymphoproliferative disorder and one due to colon carcinoma. CONCLUSION: Liver transplantation was complicated by bowel obstruction in 48 (1.2%) of 4,001 cases. While adhesions and incisional hernias are common and well recognized, other causes are more challenging to diagnose. The CT findings reported here may allow more accurate diagnosis of internal hernia.

Performance of CT in detection of bowel injury.

OBJECTIVE: The objective of our study was to identify relevant and reliable CT signs of bowel injury, to determine the overall performance of CT in detection of bowel injuries, and to establish the effect of the training level of radiologists on this performance. MATERIALS AND METHODS: Abdominal CT scans of 112 patients with blunt abdominal trauma were prospectively and retrospectively reviewed. Fifty patients had proven bowel injuries (with or without other visceral injuries), whereas 62 patients had no bowel injury and comprised the comparison or control group. Thirty-one of the 62 patients in the comparison group had surgical proof of abdominal but not bowel or mesenteric injuries. The retrospective review of the 112 CT scans was performed randomly and individually by nine radiologists unaware of the diagnosis, including three faculty abdominal radiologists, three senior residents in training, and three junior residents in training. Individual performance and group performance were evaluated by receiver operating characteristic analysis, and interobserver agreement was tested. Individual CT signs as relevant predictors of bowel injury were identified by logistic regression. RESULTS: Relevant predictors of bowel injury included mesenteric infiltration, bowel wall thickening, extravasation of vascular or enteric contrast agent, and the presence free air. In the retrospective blinded review, CT showed good to excellent interobserver reliability for individual CT signs as well as for diagnosis of bowel and visceral injuries. Faculty radiologists tended to diagnose injuries with greater accuracy and confidence, but they showed significantly better performance than residents only in diagnosing duodenal perforation. For the prospective CT diagnosis of bowel injury, CT had a sensitivity of 64%, an accuracy of 82%, and a specificity of 97%. CONCLUSION: Bowel injuries are challenging to diagnose on CT. Radiologists with various levels of experience and expertise can achieve accurate and reproducible results using a variety of CT criteria.