title: The accuracy of 64-slice MDCT for determining the perforation site of the gastrointestinal tract: ROC analysis.
abstract: OBJECTIVE
  This study was performed to evaluate the diagnostic performance of 64-slice multidetector-row computed tomography (MDCT) for preoperatively detecting the perforation site in patients with gastrointestinal (GI) tract perforations.
  
  
  METHODS
  A total of 49 patients with pathologically proven GI tract perforations, who had undergone MDCT were included in this study. The contrast-enhanced axial images (3 mm thick) and multiplanar reformation (MPR) images (3 mm thick) were generated for all the patients. Two radiologists independently reviewed the two sets of MDCT images (axial set: the axial images alone, and combined set: the axial and MPR images) for the detection of the perforation site. The perforation site was considered to be positive according to the direct and indirect findings. The diagnostic accuracy was assessed with a receiver operating characteristic (ROC) analysis. Weighted kappa statistics were used to evaluate the interobserver agreement.
  
  
  RESULTS
  The corresponding values in respect of the first and the second observers for the areas under the ROC curve were 0.984 and 0.966 for the axial set; and 0.998 and 0.973 for the combined set. The differences were not statistically significant between the two data sets for each observer (P > 0.05). Both the observers detected the perforation site in 43 (87.8%) and 40 (81.6%) patients on the axial set, and in 46 (93.9%) and 41 (83.7%) patients on the combined set, respectively. The kappa values between the two observers showed excellent agreement with the two data sets.
  
  
  CONCLUSIONS
  64-slice MDCT showed a consistently excellent diagnostic performance for preoperatively determining the perforation site in patients with GI tract perforations, irrespective of the availability of the MPR images.
authors.affiliation: Department of Radiology, Chonnam National University Hwasun Hospital, Jeollanam-do, South Korea.
authors.forename: Jin Woong
authors.initials: JW
authors.lastname: Kim
authors.forename: Sang Soo
authors.initials: SS
authors.lastname: Shin
authors.forename: Suk Hee
authors.initials: SH
authors.lastname: Heo
authors.forename: Yong Yeon
authors.initials: YY
authors.lastname: Jeong
authors.forename: Heoung Keun
authors.initials: HK
authors.lastname: Kang
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media; D005260:Female; D006801:Humans; D007416:Intestinal Perforation / Q000000981:diagnostic imaging* / Q000209:etiology; D007472:Iohexol / Q000031:analogs & derivatives; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography; D012372:ROC Curve; D011857:Radiographic Image Interpretation, Computer-Assisted; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; D007472:Iohexol; C038192:iopromide