Identification of adhesions on CT in small-bowel obstruction.

Identification of adhesions on computed tomography (CT) in cases of small-bowel obstruction (SBO) is currently a diagnosis of exclusion. The purpose of this study is to examine whether the presence of findings suggestive of an extraluminal band can be used as a CT sign for adhesive SBO. CT scans of 142 patients with surgically proven SBO performed within 72 h of exploratory surgery were reviewed. The studies were evaluated for the cause of SBO and the presence of extraluminal bands. An extraluminal band was considered present if there was a change in the conformation of the transition zone, suggesting extraluminal compression of the bowel by a linear obstructive band. The presence of extraluminal bands in the area of the transition zone had a high positive predictive value for adhesive SBO. Of the 73 cases in which bands were present, SBO was due to adhesions in 52 instances, with a corresponding positive predictive value of 71% (95% confidence interval 0.60-0.80) and a p value of 0.008. The extraluminal band was 61% sensitive and 63% specific for adhesive SBO. The presence of an extraluminal band on CT in the area of the transition zone in cases of SBO correlates well with a diagnosis of SBO secondary to adhesions. In the absence of a source of SBO, the presence of an extraluminal band can serve as a helpful diagnostic adjunct for adhesive SBO.