title: CT of small-bowel ischemia associated with obstruction in emergency department patients: diagnostic performance evaluation.
abstract: OBJECTIVE
  To retrospectively evaluate the diagnostic performance of computed tomography (CT) for detection of small-bowel ischemia in emergency department patients with abdominal pain and to compare the prospective interpretation with a retrospective interpretation by using surgical or pathologic findings as the reference standard.
  
  
  METHODS
  The HIPAA-compliant study was approved by the institutional review board, and patients consented to research authorization. Sixty patients (61 examinations) (25 male, 35 female patients; median age, 67 years; range, 0.9-89.7 years) with acute abdominal pain underwent immediate abdominal and pelvic CT and subsequent surgery of the small bowel within 7 days of CT. Prospective radiologic reports were reviewed for diagnosis of small-bowel obstruction and ischemia. Two gastrointestinal radiologists performed blinded, independent, retrospective review of the CT studies with no clinical data other than presence of acute abdominal pain. The reviewers categorized CT signs of obstruction and ischemia and estimated diagnostic certainty. Discordant findings were resolved by consensus review by a third gastrointestinal radiologist. CT interpretations were compared with prospective interpretations and surgical or pathologic findings. Sensitivity and specificity estimates with confidence intervals were calculated. Fisher exact and chi2 tests were used to assess associations between CT signs and the diagnosis of ischemia; kappa statistics were used to estimate agreement between readers.
  
  
  RESULTS
  In 27 (44%) of 61 CT studies, small-bowel ischemia was surgically or pathologically confirmed. Sensitivity and specificity for the diagnosis of ischemia were, respectively, 14.8% and 94.1% for prospective interpretations, 29.6% and 91.2% for reader 1, 40.7% and 85.3% for reader 2, and 51.9% and 88.2% for the consensus review. Decreased segmental enhancement was the most specific sign for small-bowel ischemia (P = .001), and its recognition would have improved the diagnostic performance of all readers. There was a significant association of the small-bowel feces sign with the presence of small-bowel ischemia (P = .046).
  
  
  CONCLUSIONS
  Diagnostic performance assessment of CT for the diagnosis of small-bowel ischemia revealed poor prospective interpretation sensitivity.
authors.affiliation: Division of Abdominal Imaging, Department of Radiology, Mayo Clinic College of Medicine, Mayo W2, 200 First St SW, Rochester, MN 55905, USA.
authors.forename: Shannon P
authors.initials: SP
authors.lastname: Sheedy
authors.forename: Frank
authors.initials: F
authors.lastname: Earnest
authors.forename: Joel G
authors.initials: JG
authors.lastname: Fletcher
authors.forename: Jeff L
authors.initials: JL
authors.lastname: Fidler
authors.forename: Tanya L
authors.initials: TL
authors.lastname: Hoskin
mesh_terms: D015746:Abdominal Pain / Q000000981:diagnostic imaging / Q000209:etiology / Q000601:surgery; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016009:Chi-Square Distribution; D002648:Child; D002675:Child, Preschool; D003287:Contrast Media; D003937:Diagnosis, Differential; D004636:Emergency Service, Hospital; D005260:Female; D006801:Humans; D007223:Infant; D007415:Intestinal Obstruction / Q000150:complications / Q000000981:diagnostic imaging* / Q000601:surgery; D007421:Intestine, Small / Q000098:blood supply* / Q000000981:diagnostic imaging / Q000601:surgery; D007472:Iohexol; D007511:Ischemia / Q000150:complications / Q000000981:diagnostic imaging* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*; D016896:Treatment Outcome
chemical_list: D003287:Contrast Media; D007472:Iohexol