title: Increased unenhanced bowel-wall attenuation at multidetector CT is highly specific of ischemia complicating small-bowel obstruction.
abstract: OBJECTIVE
  To evaluate performance of increased bowel-wall attenuation on unenhanced 64-section multidetector computed tomographic (CT) images for diagnosing bowel-wall ischemia in patients with mechanical small-bowel obstruction (SBO) and to evaluate the diagnostic accuracy of multidetector CT in detecting small-bowel ischemia complicating SBO, with surgical and histopathologic findings as reference standard.
  
  
  METHODS
  The local institutional review board approved this retrospective study; informed consent requirement was waived. In 44 patients (10 men, 34 women; age range, 30-100 years) who were admitted because they were suspected of having SBO and treated surgically within the next 7 days, 45 multidetector CT scans were retrospectively reviewed. Two gastrointestinal radiologists performed independent blinded reviews of images to identify specific signs of ischemia; disagreements were resolved in consensus with a third gastrointestinal radiologist. Results were compared with both findings in prospective radiology reports and surgical and histopathologic findings. Fisher exact and χ(2) tests were used to assess associations between CT signs and ischemia, and the κ statistic was used to assess interobserver agreement.
  
  
  RESULTS
  In 19 of 45 (42%) multidetector CT scans, ischemia was confirmed at surgery and/or histopathologic examination. Increased bowel-wall attenuation on unenhanced images was significantly associated with ischemia (P < .0001); in this highly selected population, this sign had a 100% (24 of 24) specificity and a 56% (10 of 18) sensitivity. Sensitivity and specificity of multidetector CT for ischemia were 63% (12 of 19) and 92% (24 of 26), respectively, for the prospective reports and 84% (16 of 19) and 96% (25 of 26), respectively, for the consensus review. Decreased segmental bowel-wall enhancement was the most accurate 64-section multidetector CT sign for diagnosing ischemia (sensitivity, 78% [14 of 18]; specificity, 96% [24 of 25]; P < .0001). The small-bowel feces sign was significantly associated with ischemia (P = .0308).
  
  
  CONCLUSIONS
  Increased bowel-wall attenuation on unenhanced 64-section multidetector CT images is a specific sign for ischemia complicating SBO. Diagnostic accuracy of 64-section multidetector CT for ischemia associated with SBO was excellent.
authors.affiliation: From the Department of Radiology, Fondation Hôpital Saint-Joseph, 185 rue Raymond Losserand, 75014 Paris, France (Y.G., I.B., M.C.J., S.N., M.Z.); Department of Radiology, Hôpital d'Instruction des Armées Laveran (Marseille), Marseille, France (Y.G.); and Department of Radiology, CHU Lapeyronie, Montpellier, France (P.T.).
authors.forename: Yann
authors.initials: Y
authors.lastname: Geffroy
authors.forename: Isabelle
authors.initials: I
authors.lastname: Boulay-Coletta
authors.forename: Marie-Christine
authors.initials: MC
authors.lastname: Jullès
authors.forename: Serge
authors.initials: S
authors.lastname: Nakache
authors.forename: Patrice
authors.initials: P
authors.lastname: Taourel
authors.forename: Marc
authors.initials: M
authors.lastname: Zins
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media; D005260:Female; D006801:Humans; D007415:Intestinal Obstruction / Q000150:complications* / Q000000981:diagnostic imaging* / Q000601:surgery; D007421:Intestine, Small / Q000098:blood supply* / Q000000981:diagnostic imaging* / Q000601:surgery; D007479:Iopamidol / Q000031:analogs & derivatives; D007511:Ischemia / Q000000981:diagnostic imaging* / Q000209:etiology* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media; C057937:iomeprol; D007479:Iopamidol