Defining the Long-Term Clinical Course and Need for Repeat Dilation for Patients With Schatzki Rings.

Schatzki rings (SRs) are a well-known cause of intermittent solid-food dysphagia.1 Although some patients sustain improvement after 1 endoscopic dilation, others require repeated dilations for recurrent symptoms.2-4 SRs are believed to be distinct from strictures caused by gastroesophageal reflux disease. SRs are sharply localized lesions with clearly defined margins, whereas peptic strictures have a more gradual transition between normal and abnormal esophagus to produce a funnel-shaped narrowing.5,6 Consequently, it has been assumed that repeat dilation is less common in SRs dissimilar from medically untreated peptic strictures. The study aim was to identify clinical and radiologic predictors for repeated esophageal dilations in patients with SRs and to assess if peptic stricture-like characteristics of rings correspond to need for repeat dilation.

Imaging Review of Gastrointestinal Motility Disorders.

The motor function of the gastrointestinal tract relies on the enteric nervous system, which includes neurons spanning from the esophagus to the internal anal sphincter. Disorders of gastrointestinal motility arise as a result of disease within the affected portion of the enteric nervous system and may be caused by a wide array of underlying diseases. The etiology of motility disorders may be primary or due to secondary causes related to infection or inflammation, congenital abnormalities, metabolic disturbances, systemic illness, or medication-related side effects. The symptoms of gastrointestinal dysmotility tend to be nonspecific and may cause diagnostic difficulty. Therefore, evaluation of motility disorders requires a combination of clinical, radiologic, and endoscopic or manometric testing. Radiologic studies including fluoroscopy, CT, MRI, and nuclear scintigraphy allow exclusion of alternative pathologic conditions and serve as adjuncts to endoscopy and manometry to determine the appropriate diagnosis. Additionally, radiologist understanding of clinical evaluation of motility disorders is necessary for guiding referring clinicians and appropriately imaging patients. New developments and advances in imaging techniques have allowed improved assessment and diagnosis of motility disorders, which will continue to improve patient treatment options. Online supplemental material is available for this article. ©RSNA, 2022.

CT for Evaluation of Acute Gastrointestinal Bleeding.

Acute gastrointestinal (GI) bleeding is common and necessitates rapid diagnosis and treatment. Bleeding can occur anywhere throughout the GI tract and may be caused by many types of disease. The variety of enteric diseases that cause bleeding and the tendency for bleeding to be intermittent may make it difficult to render a diagnosis. The workup of GI bleeding is frequently prolonged and expensive, with examinations commonly needing to be repeated. The use of computed tomography (CT) for evaluation of acute GI bleeding is gaining popularity because it can be used to rapidly diagnose active bleeding and nonbleeding bowel disease. The CT examinations used to evaluate acute GI bleeding include CT angiography and multiphase CT enterography. Understanding the clinical evaluation of acute GI bleeding, including the advantages and limitations of endoscopic evaluation, is necessary for the appropriate selection of patients who may benefit from CT. Multiphase CT enterography is used primarily to evaluate stable patients who have undergone upper and lower endoscopy without identification of a bleeding source. CT angiography is used to examine stable and unstable patients who respond to resuscitation, are believed to be actively bleeding, and are considered unlikely to have an upper GI source of hemorrhage. In the emergent setting, CT may yield critical information regarding the presence, location, and cause of active bleeding-data that can guide the choice of subsequent therapy. Recent developments in the use of and techniques for performing CT angiography have made it a potential first-line tool for evaluating acute GI bleeding. ©RSNA, 2018.

J Pouch: Imaging Findings, Surgical Variations, Natural History, and Common Complications.

Ileal pouch-anal anastomosis, or J pouch, surgery has become the procedure of choice for treatment of medically refractory ulcerative colitis and familial adenomatous polyposis. Overall, this operation is associated with a low rate of postoperative morbidity and good long-term function. However, when complications develop, there is a heavy reliance on imaging to facilitate an accurate diagnosis. Reported postoperative complication rates range from 5% to 35%. Complications generally can be categorized as structural, inflammatory, or neoplastic conditions. Structural complications include leaks, strictures, afferent and efferent limb syndromes, and pouch prolapse. Inflammatory conditions include cuffitis, pouchitis, and Crohn disease of the pouch. In addition, a variety of neoplastic conditions can develop in the pouch. Overall, pouchitis and leaks are the most common complications, occurring in up to 50% and 20% of individuals, respectively. Many imaging modalities are used to evaluate the J pouch and associated postoperative complications. The indications and various surgical techniques for J pouch surgery, normal postoperative appearance of the pouch, and most common associated complications are reviewed. In addition, the various imaging findings associated with J pouch surgery are described and illustrated. The radiologist's familiarity with the potential complications of the pouch can facilitate appropriate imaging, hasten an accurate diagnosis, and aid in rendering proper management. ©RSNA, 2018.

Radiological Response Is Associated With Better Long-Term Outcomes and Is a Potential Treatment Target in Patients With Small Bowel Crohn's Disease.

OBJECTIVES: Crohn's disease (CD) management targets mucosal healing on ileocolonoscopy as a treatment goal. We hypothesized that radiologic response is also associated with better long-term outcomes. METHODS: Small bowel CD patients between 1 January 2002 and 31 October 2014 were identified. All patients had pre-therapy computed tomography enterography (CTE)/magnetic resonance enterography (MRE) with follow-up CTE or MRE after 6 months, or 2 CTE/MREs≥6 months apart while on maintenance therapy. Radiologists characterized inflammation in up to five small bowel lesions per patient. At second CTE/MRE, complete responders had all improved lesions, non-responders had worsening or new lesions, and partial responders had other scenarios. CD-related outcomes of corticosteroid usage, hospitalization, and surgery were assessed using Kaplan-Meier survival analysis and multivariable Cox models. RESULTS: CD patients (n=150), with a median disease duration of 9 years, had 223 inflamed small bowel segments (76 with strictures and 62 with penetrating, non-perianal disease), 49% having ileal distribution. Fifty-five patients (37%) were complete radiologic responders, 39 partial (26%), and 56 non-responders (37%). In multivariable Cox models, complete and partial response decreased risk for steroid usage by over 50% (hazard ratio (HR)s: 0.37 (95% confidence interval (CI), 0.21-0.64); 0.45 (95% CI, 0.26-0.79)), and complete response decreased the risk of subsequent hospitalizations and surgery by over two-thirds (HRs: HR, 0.28 (95% CI, 0.15-0.50); HR, 0.34 (95% CI, 0.18-0.63)). CONCLUSIONS: Radiological response to medical therapy is associated with significant reductions in long-term risk of hospitalization, surgery, or corticosteroid usage among small bowel CD patients. These findings suggest the significance of radiological response as a treatment target.

Evaluation of Patient Tolerance and Small-Bowel Distention With a New Small-Bowel Distending Agent for Enterography.

OBJECTIVE: The objective of our study was to compare a flavored beverage containing a thickening agent for enterography with a low-Hounsfield-value barium suspension for side effects, taste, subjects' willingness to repeat the drinking protocol, and small-bowel distention. SUBJECTS AND METHODS: The following five drinking protocols were administered to 10 volunteers: 1000 mL of flavored beverage followed by 350 mL of water, 1500 mL of flavored beverage, 900 mL of low-Hounsfield-value barium suspension followed by 450 mL of water, 1350 mL of low-Hounsfield-value barium suspension followed by 150 mL of water, and 1500 mL of water. MR images were obtained 50 and 60 minutes after initiation of drinking. Subjects completed a questionnaire evaluating the side effects, the taste of the drink, and their willingness to repeat the drinking protocol. Reviewers assigned scores evaluating small-bowel distention and ranked the examinations in order of preference. RESULTS: There was no significant difference in nausea or vomiting among the protocols (p = 0.20 and 0.42, respectively), but larger volumes of flavored beverage and low-Hounsfield-value barium suspension resulted in more cramping and diarrhea (p = 0.001 and 0.002, respectively). The taste of the low-Hounsfield-value barium suspension was rated the worst (p < 0.0001). The subjects' willingness to repeat the drinking protocol was highest for the 1000 mL of flavored beverage or water alone (p < 0.05). There were no significant differences in subjective small-bowel distention except that water was rated the worst by two of the three readers (p < 0.02). There was no significant difference in the diameter of the most dis-tended small bowel for any segment or reader (p > 0.23). CONCLUSION: A flavored beverage containing a thickening agent has a similar side effect profile and results in equivalent small-bowel distention compared with a low-Hounsfield-value barium suspension, but subjects rate taste and their willingness to repeat the drinking protocol higher for this new agent.

CT enterography: technical and interpretive pitfalls.

CT enterography is a first-line test at many institutions to investigate potential small bowel disorders. While numerous articles have focused on the ability of CT enterography to diagnose and stage Crohn's disease, small bowel neoplasia, and malabsorptive or vascular disorders, this article reviews CT enterography limitations, technical and interpretive pitfalls, image review tactics, and complementary radiologic and endoscopic examinations to improve diagnostic accuracy. CT enterography limitations include its inability to demonstrate isolated mucosal abnormalities such as aphthous ulcers and its use of ionizing radiation. The most common technical pitfall of CT enterography is inadequate small bowel distention resulting from inadequate ingestion, gastric retention, or rapid small bowel transit of a large volume of neutral enteric contrast material. Additionally, segments of jejunum are frequently collapsed. Interpretive pitfalls commonly result from peristaltic contractions, transient intussusception and opaque intraluminal debris. Opaque debris is especially problematic during multiphasic CT enterography performed to identify potential small bowel sources of obscure gastrointestinal bleeding. False-negative examinations may result from inadequate radiation dose. Examinations complementary to CT enterography include small bowel follow through, enteroclysis, CT enteroclysis, MR enterography, MR enteroclysis, capsule endoscopy, and balloon-assisted endoscopy. Properly performed and accurately interpreted CT enterography contributes to the diagnosis and management of small bowel disease by itself and as a complement to other radiologic and optical small bowel imaging examinations.

NSAID enteropathy: appearance at CT and MR enterography in the age of multi-modality imaging and treatment.

CT and MR enterography and capsule endoscopy are increasingly used as routine diagnostic tests for patients with potential small bowel disorders and obscure gastrointestinal bleeding. Non-steroidal anti-inflammatory drugs (NSAIDs) are commonly used drugs that disrupt prostaglandin synthesis and result in a variety of localized complications within the small bowel ranging from ulcer formation to characteristic circumferential strictures, or diaphragms. NSAID enteropathy encompasses this spectrum of acute and chronic inflammatory sequelae, and is associated with typical findings at capsule endoscopy and surgery. Herein we review the typical clinical presentation of NSAID enteropathy, in addition to its endoscopic appearances, focusing on imaging findings at cross-sectional enterography. Multiple, short-segment strictures are the hallmarks of imaging diagnosis. Strictures may have minimal hyperenhancement or wall thickening, but these findings are typically symmetric and circumferential with respect to the bowel lumen. Multifocal Crohn's strictures, and occasionally radiation-induced strictures or adhesions, will mimic NSAID diaphragms. Multi-phase or multi-sequence imaging at CT and MR enterography increase diagnostic confidence in stricture presence. Strategies for subsequent workup and therapy after enterography are also discussed. Given the frequent use of NSAIDs and typical appearance of these strictures, knowledge of characteristic imaging findings can be particularly useful when evaluating patients with anemia and recurrent small bowel obstruction.

Observer performance for adaptive, image-based denoising and filtered back projection compared to scanner-based iterative reconstruction for lower dose CT enterography.

PURPOSE: The purpose of this study was to compare observer performance for detection of intestinal inflammation for low-dose CT enterography (LD-CTE) using scanner-based iterative reconstruction (IR) vs. vendor-independent, adaptive image-based noise reduction (ANLM) or filtered back projection (FBP). METHODS: Sixty-two LD-CTE exams were performed. LD-CTE images were reconstructed using IR, ANLM, and FBP. Three readers, blinded to image type, marked intestinal inflammation directly on patient images using a specialized workstation over three sessions, interpreting one image type/patient/session. Reference standard was created by a gastroenterologist and radiologist, who reviewed all available data including dismissal Gastroenterology records, and who marked all inflamed bowel segments on the same workstation. Reader and reference localizations were then compared. Non-inferiority was tested using Jackknife free-response ROC (JAFROC) figures of merit (FOM) for ANLM and FBP compared to IR. Patient-level analyses for the presence or absence of inflammation were also conducted. RESULTS: There were 46 inflamed bowel segments in 24/62 patients (CTDIvol interquartile range 6.9-10.1 mGy). JAFROC FOM for ANLM and FBP were 0.84 (95% CI 0.75-0.92) and 0.84 (95% CI 0.75-0.92), and were statistically non-inferior to IR (FOM 0.84; 95% CI 0.76-0.93). Patient-level pooled confidence intervals for sensitivity widely overlapped, as did specificities. Image quality was rated as better with IR and AMLM compared to FBP (p < 0.0001), with no difference in reading times (p = 0.89). CONCLUSIONS: Vendor-independent adaptive image-based noise reduction and FBP provided observer performance that was non-inferior to scanner-based IR methods. Adaptive image-based noise reduction maintained or improved upon image quality ratings compared to FBP when performing CTE at lower dose levels.

Clinical characteristics and imaging features of small bowel adenocarcinomas in Crohn's disease.

PURPOSE: Small bowel adenocarcinoma is uncommon in patients with Crohn's disease but has an extremely poor prognosis. There is a paucity of data on the clinical characteristics and radiologic features of this entity. We sought to update our institutional experience with small bowel adenocarcinoma occurring in the setting of Crohn's disease and to systematically re-examine pre-operative imaging findings. METHODS: Medical records were abstracted to identify all patients with Crohn's disease and small bowel adenocarcinoma who were evaluated at Mayo Clinic, Rochester, Minnesota and Mayo Clinic, Scottsdale, Arizona between 1976 and 2012. Clinical, demographic, and outcomes data were obtained for each patient. Pre-diagnosis radiologic imaging was re-evaluated by two gastrointestinal radiologists. RESULTS: Thirty-four patients (21 males) were identified. Median ages at Crohn's disease and cancer diagnoses were 22.4 and 52.9 years, respectively. Median follow-up after cancer diagnosis was 272.0 days; 22 patients (64.7%) had persistent or recurrent adenocarcinoma at last follow-up. 1- and 2-year mortality rates were 29.6% and 48.0%. Pre-operative imaging studies were available for re-review in 14 cases. Features concerning for malignancy included annular mass, nodularity at the extraluminal margins of the mass, and perforation. Nearly all tumors arose in regions of chronic inflammation and caused luminal narrowing with pre-stenotic dilatation. CONCLUSIONS: Small bowel adenocarcinoma is rare in patients with Crohn's disease but results in significant mortality. CT or MR imaging findings can be suggestive of the pre-operative diagnosis, but it is usually diagnosed at an advanced stage with laparotomy.

Validation of a CT-derived method for osteoporosis screening in IBD patients undergoing contrast-enhanced CT enterography.

OBJECTIVES: Osteoporosis and bone fractures are of particular concern in patients with inflammatory bowel disease (IBD). Biomechanical computed tomography (BCT) is an image-analysis technique that can measure bone strength and dual-energy X-ray absorptiometry (DXA)-equivalent bone mineral density (BMD) from noncontrast CT images. This study seeks to determine whether this advanced technology can be applied to patients with IBD undergoing CT enterography (CTE) with IV contrast. METHODS: Patients with IBD who underwent a CTE and DXA scan between 2007 and 2011 were retrospectively identified. Femoral neck BMD (g/cm(2)) and T-scores were measured and compared between DXA and BCT analysis of the CTE images. Femoral strength (Newtons) was also determined from BCT analysis. RESULTS: DXA- and CTE-generated BMD T-score values were highly correlated (R(2)=0.84, P<0.0001) in this patient cohort (n=136). CTE identified patients with both osteoporosis (sensitivity, 85.7%; 95% confidence interval (CI), 48.7-97.4 and specificity, 98.5%; 95% CI, 94.5-99.6) and osteopenia (sensitivity, 85.1%; 95% CI, 72.3-92.6 and specificity, 85.4%; 95% CI, 76.6-91.3). Of the 16 patients who had "fragile" bone strength by BCT (placing them at the equivalent high risk of fracture as for osteoporosis), 6 had osteoporosis and 10 had osteopenia by DXA. CONCLUSIONS: CTE scans can provide hip BMD, T-scores, and clinical classifications that are comparable to those obtained from DXA; when combined with BCT analysis, CTE can identify a subset of patients with osteopenia who have clinically relevant fragile bone strength. This technique could markedly increase bone health assessments in IBD patients already undergoing CTE to evaluate small bowel disease.

Multiphase CT enterography evaluation of small-bowel vascular lesions.

OBJECTIVE: By use of multiphase CT enterography (CTE), small-bowel vascular lesions associated with gastrointestinal bleeding can be classified into three categories--angioectasias, arterial lesions, and venous abnormalities--on the basis of common morphology and enhancement patterns. This article will review the unique patterns of enhancement and lesion morphology seen on multiphase CTE and how those findings enable detection and characterization of specific lesions in many cases. CONCLUSION: Because of the high prevalence in nonbleeding patients and frequent multiplicity of angioectasias, determining the clinical benefit from their detection by multiphase CTE and endoscopy is problematic. Although arterial lesions are less commonly encountered clinically, their detection is critically important because of a high risk of life-threatening bleeding. Along with wireless capsule endoscopy and balloon-assisted endoscopy, multiphase CTE is a useful tool for the evaluation of patients with obscure gastrointestinal bleeding due to small-bowel vascular lesions.

Automatic selection of tube potential for radiation dose reduction in vascular and contrast-enhanced abdominopelvic CT.

OBJECTIVE: The purpose of this study is to assess the ability of a novel automatic tube potential selection tool to reduce radiation dose while maintaining diagnostic quality in CT angiography (CTA) and contrast-enhanced abdominopelvic CT. MATERIALS AND METHODS: One hundred one CTA examinations and 90 contrastenhanced abdominopelvic examinations were performed using an automatic tube potential selection tool on a 128-MDCT scanner. Two vascular radiologists and two abdominal radiologists evaluated the image quality for sharpness, noise, artifact, and diagnostic confidence. In a subset of patients who had undergone prior studies (CTA, 28 patients; abdominopelvic CT, 25 patients), a side-by-side comparison was performed by a separate radiologist. Dose reduction and iodine contrast-to-noise ratio resulting from use of the tool were calculated. RESULTS: For CTA, 80 or 100 kV was selected for 73% of the scans, with a mean dose reduction of 36% relative to the reference 120-kV protocol. For abdominopelvic CT examinations, 80 or 100 kV was used for 55% of the scans, with a mean dose reduction of 25%. Overall dose reduction relative to the reference 120-kV protocol was 25% and 13% for CTA and abdominopelvic CT scans, respectively. Over 98% of scans had acceptable sharpness, noise texture, artifact, and diagnostic confidence for both readers and diagnostic tasks; 94-100% of scans had acceptable noise. Iodine contrast-to-noise ratio was significantly higher than (p < 0.001) or similar to (p = 0.11) that of prior scans, and equivalent quality was achieved despite the dose reduction. CONCLUSION: Automatic tube potential selection provides an efficient and quantitativeway to guide the selection of the optimal tube potential for CTA and abdominopelvic CT examinations.

Management of Epiphrenic Diverticula and Short-term Outcomes.

Epiphrenic diverticulum is a rare and benign condition with significant surgical morbidity and evolving surgical management. The objective of this study was to analyze short-term clinical outcomes after surgery for epiphrenic diverticula. We conducted a retrospective cohort study in a single tertiary care center of all patients who underwent treatment for epiphrenic esophageal diverticula from June 1990 to December 2016. Data collection included demographics, operative details and short-term outcomes (esophageal leak, other complications, 30-day mortality). In addition, all preoperative imaging was reviewed by an esophageal radiologist in order to describe epiphrenic diverticula characteristics in a uniform and blinded manner. Of the 94 patients in the study, 84 patients were managed with an open surgical approach and 10 with minimally invasive techniques. Median size of diverticula was 5.5 cm and mean height above gastroesophageal junction was 4 cm. A myotomy was completed in 95% of patients and a fundoplication in 58%. The MIS group had a shorter length of stay (4 vs 6 days). Overall complication rate was 27% with an esophageal leak rate of 7% with 60% grade I leaks that sealed with conservative management. Complete resection of the diverticulum, closure of the muscle over the resection, contralateral myotomy, and consideration for partial fundoplication are common strategies utilized to surgically treat patients with epiphrenic diverticulum. Minimally invasive approaches are increasingly utilized.

The evolving role of imaging for small bowel neuroendocrine neoplasms: estimated impact of imaging and disease-free survival in a retrospective observational study.

PURPOSE: To determine how small bowel neuroendocrine neoplasms (SBNEN's) are diagnosed and examine the effect of CT enterography (CTE) on diagnosis and rates of disease-free survival. METHODS: Histopathologically-confirmed SBNEN's diagnosed at our institution between 1996 and 2016 were identified. Clinical presentation, radiology, endoscopy, surgery, and pathology reports were reviewed and compared between consecutive 5-year periods. RESULTS: Of the 178 SBNEN initially diagnosed at our institution, the incidence increased 12-fold from 9 (during 1996-2000) to 114 (during 2011-2016). Comparing the first 5 to the last 5 years, GI bleeding and abdominal pain increased significantly as indications (with both increasing from 0 to > 25%, p ≤ 0.023). Initial diagnosis by radiology increased 2-fold [from 33% (n = 3) to 66% (n = 75); p = 0.263]. Detection of a small bowel mass and the suggestion that SBNEN was present varied significantly between imaging modalities (p < 0.0001; CTE - 95% (52/55) and 91% (50/55) vs. abdominal CT 45% (37/85) and 35% (29/85), respectively). Recurrence rates increased with SBNEN size (p = 0.012; e.g., of SBNEN diagnosed by endoscopy, 18% of SBNEN measuring 0.6 ± 0.3 cm recurred vs. 75% measuring 3.7 ± 1.0 cm). Rates of disease-free survival, and the incidence of local and liver metastases were decreased when tumors were first identified by CTE rather than other CT/MR imaging modalities (p = 0.0034, 0.0475, and 0.0032, respectively). CONCLUSION: There has been a dramatic increase in SBNENs detected by CTE and endoscopy over the last 20 years. SBNEN's detected by CTE and small tumors detected at endoscopy have longer disease-free survival after surgical resection.

Multiphase Computed Tomographic Enterography: Diagnostic Yield and Efficacy in Patients With Suspected Small Bowel Bleeding.

OBJECTIVE: To estimate the diagnostic yield and efficacy of multiphase computed tomographic enterography (mpCTE) for suspected small bowel bleeding in routine clinical practice. PATIENTS AND METHODS: All mpCTEs performed between January 1, 2006, and December 31, 2014, for suspected small bowel bleeding were included and classified by a gastroenterologist and an abdominal radiologist. The reference standard for a definitive diagnosis was balloon-assisted enteroscopic, angiographic, surgical, or pathologic results. Overall and lesion-specific diagnostic yield (DY), sensitivity, and positive predictive value were calculated. The relationship of mpCTE diagnosis and continued bleeding or iron supplementation was examined using logistic regression in patients with at least 1 year of follow-up. RESULTS: We identified 1087 patients who had an initial mpCTE indication of small bowel bleeding. The overall DY was 31.6% (344 of 1087 patients; 95% CI, 29.0%-35.0%), higher for an indication of small bowel bleeding that was overt or occult with heme-positive stool vs occult with only iron-deficiency anemia (DY, 35.0% [170 of 486] and 35.3% [66 of 187] vs 26.1% [108 of 414]; P=.004 and P=.02, respectively). The highest sensitivity and positive predictive value were for small bowel masses (90.2% [55 of 61] and 98.2% [55 of 56], respectively). Higher risk of future bleeding and iron supplementation was seen with a negative result on mpCTE (odds ratio [OR], 1.91; 95% CI, 1.28-2.86), lack of surgical intervention (OR, 4.37; 95% CI, 2.31-8.29), or discrepant balloon-assisted enteroscopic findings (OR, 2.50; 95% CI, 1.03-6.09). CONCLUSION: Multiphase computed tomographic enterography has a higher rate of detection in patients with overt bleeding or heme-positive stool. The procedure provides actionable targets for further intervention and leads to substantially reduced rates of rebleeding in long-term follow-up.

CT colonography: investigation of the optimum reader paradigm by using computer-aided detection software.

PURPOSE: To prospectively compare the diagnostic performance and time efficiency of both second and concurrent computer-aided detection (CAD) reading paradigms for retrospectively obtained computed tomographic (CT) colonography data sets by using consensus reading (three radiologists) of colonoscopic findings as a reference standard. MATERIALS AND METHODS: Ethical permission, HIPAA compliance (for U.S. institutions), and patient consent were obtained from all institutions for use of CT colonography data sets in this study. Ten radiologists each read 25 CT colonography data sets (12 men, 13 women; mean age, 61 years) containing 69 polyps (28 were 1-5 mm, 41 were >or=6 mm) by using workstations integrated with CAD software. Reading was randomized to either "second read" CAD (applied only after initial unassisted assessment) or "concurrent read" CAD (applied at the start of assessment). Data sets were reread 6 weeks later by using the opposing paradigm. Polyp sensitivity and reading times were compared by using multilevel logistic and linear regression, respectively. Receiver operating characteristic (ROC) curves were generated. RESULTS: Compared with the unassisted read, odds of improved polyp (>or=6 mm) detection were 1.5 (95% confidence interval [CI]: 1.0, 2.2) and 1.3 (95% CI: 0.9, 1.9) by using CAD as second and concurrent reader, respectively. Detection odds by using CAD concurrently were 0.87 (95% CI: 0.59, 1.3) and 0.76 (95% CI: 0.57, 1.01) those of second read CAD, excluding and including polyps 1-5 mm, respectively. The concurrent read took 2.9 minutes (95% CI: -3.8, -1.9) less than did second read. The mean areas under the ROC curve (95% CI) for the unassisted read, second read CAD, and concurrent read CAD were 0.83 (95% CI: 0.78, 0.87), 0.86 (95% CI: 0.82, 0.90), and 0.88 (95% CI: 0.83, 0.92), respectively. CONCLUSION: CAD is more time efficient when used concurrently than when used as a second reader, with similar sensitivity for polyps 6 mm or larger. However, use of second read CAD maximizes sensitivity, particularly for smaller lesions.

Small-bowel imaging in Crohn's disease: a prospective, blinded, 4-way comparison trial.

BACKGROUND: With the introduction of new techniques to image the small bowel, there remains uncertainty about their role for diagnosing Crohn's disease. OBJECTIVE: To assess the sensitivity and specificity of capsule endoscopy (CE), CT enterography (CTE), ileocolonoscopy, and small-bowel follow-through (SBFT) in the diagnosis of small bowel Crohn's disease. METHODS: Prospective, blinded trial. SETTING: Inflammatory bowel disease clinic at an academic medical center. PATIENTS: Known or suspected Crohn's disease. Exclusion criteria included known abdominal abscess and non-steroidal anti-inflammatory drug (NSAID) use. Partial small-bowel obstruction (PSBO) at CTE excluded patients from subsequent CE. INTERVENTIONS: Patients underwent all 4 tests over a 4-day period. MAIN OUTCOME MEASUREMENTS: Sensitivity, specificity, and accuracy of each test to detect active small-bowel Crohn's disease. The criterion standard was a consensus diagnosis based upon clinical presentation and all 4 studies. RESULTS: Forty-one CTE examinations were performed. Seven patients (17%) had an asymptomatic PSBO. Forty patients underwent colonoscopy, 38 had SBFT studies, and 28 had CE examinations. Small-bowel Crohn's disease was active in 51%, absent in 42%, inactive in 5%, and suspicious in 2% of patients. The sensitivity of CE for detecting active small-bowel Crohn's disease was 83%, not significantly higher than CTE (83%), ileocolonoscopy (74%), or SBFT (65%). However, the specificity of CE (53%) was significantly lower than the other tests (P < .05). One patient developed a transient PSBO due to CE, but no patients had retained capsules. LIMITATION: Use of a consensus clinical diagnosis as the criterion standard-but this is how Crohn's disease is diagnosed in practice. CONCLUSIONS: The sensitivity of CE for active small-bowel Crohn's disease was not significantly different from CTE, ileocolonoscopy, or SBFT. However, lower specificity and the need for preceding small-bowel radiography (due to the high frequency of asymptomatic PSBO) may limit the utility of CE as a first-line test for Crohn's disease.

Reproducible imaging features of biologically aggressive gastrointestinal stromal tumors of the small bowel.

PURPOSE: To identify reproducible CT imaging features of small bowel gastrointestinal stromal tumors (GIST) that are associated with biologic aggressiveness. METHODS: Patients with histologically proven small bowel GISTs and CT enterography or abdominopelvic CT were included. Biologic aggressiveness was established based on initial histologic grading (very low risk to malignant), with "malignant" assigned if recurrence or metastases developed subsequently. CT exams were independently evaluated by three gastrointestinal radiologists for tumor size, growth pattern, enhancement, tumor borders, necrosis, calcification, ulceration, multiplicity, internal air or enteric contrast, nodal metastasis, liver metastasis, peritoneal metastasis, ascites, and draining vein size. Inter-observer variability and imaging features associated with high-grade and malignant small bowel GISTs were determined. RESULTS: Of 78 patients with small bowel GISTs, 10/78 (13%) were high grade and 18/78 (23%) were malignant. There was moderate to substantial inter-observer agreement (Kappa > 0.4) for all findings except tumor border, ulceration, and nodal metastases. Tumor size, irregular or invasive tumor border, necrosis, liver metastasis, ascites, and iso-enhancement were associated with high-grade/malignant small bowel GISTs (p < 0.04). Internal air or enteric contrast and peritoneal metastases additionally predicted malignant behavior (p < 0.03). When imaging features predicting malignant small bowel GISTs were absent and size was ≤ 3 cm, 0% (0/16), 5% (1/19), and 5% (1/17) of patients had high grade, and 0% (0/16, 0/19, and 0/17) had malignant tumors for the three readers, respectively. CONCLUSION: Multiple, reproducibly identified, small bowel GIST imaging features suggest biologic aggressiveness. The absence of these imaging features may identify small tumors that can be followed in asymptomatic or high-risk patients.

Predictors of Durability of Radiological Response in Patients With Small Bowel Crohn's Disease.

Background: The long-term significance of radiological transmural response (TR) as a treatment goal at the first follow-up scan in small bowel Crohn's disease (CD) has been previously shown. We examined the durability of a long-term strategy of treating to a target of radiological TR and the influence of baseline predictors on the maintenance of TR. Methods: Small bowel CD patients between January 1, 2002, and December 31, 2014, were identified with serial computed tomography enterography (CTE)/magnetic resonance enterography (MRE) before and after initiation of therapy or on maintenance therapy. Overall TR (inflammatory lesions with/without strictures) w1as characterized by abdominal radiologists in up to 5 small bowel lesions per patient at each serial scan until last follow-up or small bowel resection, as response, partial response, or nonresponse. The rate of conversion between TR states and transition to surgery, including the effect of baseline patient/disease characteristics, was examined using a multistate model (mstate R-package). Results: CD patients (n = 150, 705 CTE/MRE) with a median of 4 CTE/MRE during 4.6 years of follow-up, 49% with ileal-only distribution, had 260 examined bowel segments. Conversion from response to partial response/nonresponse was 37.4% per year of follow-up with no transitions seen directly from response to surgery. Current smoking status (hazard ratio [HR], 2.2; 95% confidence interval [CI], 1.1-4.3) and internal penetrating disease at baseline scan (HR, 2.2; 95% CI, 1.2-4.1) were associated with a 2-fold increased risk of transition from partial response/nonresponse to surgery. Conclusions: Achievement and maintenance of radiological response is associated with avoidance of small bowel surgery. Continued follow-up with CTE/MRE is recommended to identify loss of response, especially in current smokers and patients with internal penetrating disease at baseline CTE/MRE.