Obscure Gastrointestinal Bleeding: Diagnostic Performance of Multidetector CT Enterography

Purpose: To evaluate the diagnostic performance of computed tomographic (CT) enterography in identifying the source of obscure gastrointestinal bleeding and to determine clinical features associated with a higher diagnostic yield of CT enterography. Materials and Methods: The institutional review board approved this study, with waiver of informed consent. CT enterographic images in 65 patients (46 men [mean age, 54 years; range, 1885 years] and 19 women [mean age, 62.1 years; range, 33-79 years]) who presented with obscure gastrointestinal bleeding between August 2005 and July 2007 were reviewed retrospectively and independently by two radiologists. The diagnostic performance of CT enterography was assessed by using the results of endoscopic and other imaging examinations, surgery, and clinical follow-up as the reference standard. Differences in the diagnostic yield of CT enterography according to patient demographic and clinical features, including age, sex, type and episode of bleeding (occult, initial overt, and recurrent overt), occurrence of recent bleeding, and history of massive bleeding, were evaluated by using univariate and multivariate logistic regression analyses. Results: CT enterography helped identify the source of obscure gastrointestinal bleeding in 16 (24.6%) of 65 patients. The sensitivity, specificity, positive predictive value, and negative predictive value of CT enterography were 55.2% (16 of 29), 100% (32 of 32), 100% (16 of 16), and 71.1% (32 of 45), respectively. Among patients' clinical features, a history of massive bleeding (diagnostic yield, 58.3% [seven of 12]; adjusted odds ratio, 7.2; P = .01) was independently associated with a higher diagnostic yield for CT enterography. Conclusion: CT enterography has a potential role in the evaluation of obscure gastrointestinal bleeding. Despite the limited sensitivity of CT enterography, positive CT enterographic findings can reliably indicate the true source of obscure gastrointestinal bleeding. CT enterography is particularly effective in helping identify the source of bleeding in patients with a history of massive bleeding. (C) RSNA, 2011