64-slice multidetector computed tomography evaluation of gastrointestinal tract perforation site: Detectability of direct findings in upper and lower GI tract

Objective: To evaluate wall discontinuity, as observed using 64-slice multidetector-row computed tomography (64-MDCT), as a direct finding (DF) indicating the perforation site in patients with gastrointestinal (GI) tract perforations. Methods: We retrospectively studied 41 consecutive patients presenting with acute abdomen and exhibiting extraluminal air (EA) on 64-MDCT. Three readers evaluated the distribution of EA, extraluminal faeces, dirty mass, dirty fat sign, extraluminal fluid collection and bowel wall thickening (i.e. conventional findings, CFs) as well as DFs. Results: Twenty-two cases were surgically or endoscopically confirmed to have upper GI tract perforations, and 19 had lower GI tract perforations. The DFs correctly identified the sites of perforation in 80.5% of patients when 2-mm-thick imaging slices were used. For the detection of upper GI tract perforations, the sensitivity, specificity and accuracy were 95.5%, 94.7% and 95.1% for the DFs and 50.0%, 100% and 73.2% for the CFs, respectively. Significant differences in sensitivity (p<0.001) and diagnostic accuracy (p<0.05) were observed between the DFs and CFs for upper GI perforations but not for lower GI tract perforations. Conclusion: DFs of the perforation site by using 64-MDCT were more sensitive and accurate than CFs for the detection of upper GI tract perforations.