title: The value of multidetector-row computed tomography for localization of obscure acute gastrointestinal bleeding.
abstract: OBJECTIVE
  There are no simple guidelines on when to perform multidetector-row computed tomography (MDCT) for diagnosis of obscure acute gastrointestinal bleeding (AGIB). We used a risk scoring system to evaluate the diagnostic power of MDCT for patients with obscure AGIB.
  
  
  METHODS
  Ninety-two patients with obscure AGIB who were referred for an MDCT scan after unsuccessful endoscopic treatment at presentation were studied. We recorded clinical data and calculated Blatchford score for each patient. Patients who required transfusion more than 500mL of blood to maintain the vital signs were classified as high-risk patients. Two radiologists independently reviewed and categorized MDCT signs of obscure AGIB. Discordant findings were resolved by consensus. One-way ANOVA was used to compare clinical data between two groups; kappa statistics were used to estimate agreement on MDCT findings between radiologists.
  
  
  RESULTS
  Of the 92 patients, 62 (67.4%) were classified as high-risk patients. Blatchford scores of high-risk patients were significantly greater than those of low-risk patients. Sensitivity for MDCT diagnosing obscure AGIB was 81% in high-risk patients, as compared with 50% in the low-risk. When used in conjunction with selection of the cut-off value of 13 in Blatchford scoring system, the sensitivity and specificity of MDCT were 70.9% and 73.7%, respectively. Contrast extravasation was the most specific sign of AGIB (k=.87), recognition of which would have improved diagnostic accuracy.
  
  
  CONCLUSIONS
  With the aid of Blatchford scoring system for evaluating the disease severity, MDCT can localize the bleeders of obscure AGIB more efficiently.
authors.affiliation: Department of Radiology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, ROC.
authors.forename: Wei-Chou
authors.initials: WC
authors.lastname: Chang
authors.forename: Shih-Hung
authors.initials: SH
authors.lastname: Tsai
authors.forename: Wei-Kuo
authors.initials: WK
authors.lastname: Chang
authors.forename: Chang-Hsien
authors.initials: CH
authors.lastname: Liu
authors.forename: Ho-Jui
authors.initials: HJ
authors.lastname: Tung
authors.forename: Chung-Bao
authors.initials: CB
authors.lastname: Hsieh
authors.forename: Guo-Shu
authors.initials: GS
authors.lastname: Huang
authors.forename: Hsian-He
authors.initials: HH
authors.lastname: Hsu
authors.forename: Chih-Yung
authors.initials: CY
authors.lastname: Yu
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D000792:Angiography; D001803:Blood Transfusion / Q000706:statistics & numerical data; D003287:Contrast Media; D003937:Diagnosis, Differential; D004621:Embolization, Therapeutic; D016099:Endoscopy, Gastrointestinal; D005119:Extravasation of Diagnostic and Therapeutic Materials; D005260:Female; D006471:Gastrointestinal Hemorrhage / Q000000981:diagnostic imaging* / Q000628:therapy; D006801:Humans; D007472:Iohexol; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012372:ROC Curve; D015641:Radiography, Interventional; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media; D007472:Iohexol