Obstruction of the small intestine: accuracy and role of CT in diagnosis.

The reliability of abdominal computed tomography (CT) in the assessment of varying degrees of small bowel obstruction (SBO) was evaluated by using results at enteroclysis and clinical outcome as standards of reference. A blinded retrospective analysis was performed of the studies of 55 patients who underwent both CT and enteroclysis in the course of assessment for suspected SBO. Nine patients had no obstruction, 40 patients had obstruction due to adhesions, and six patients had tumor-related obstruction. CT results were used to identify correctly 63% (29 of 46) of those who had SBO and 78% (seven of nine) of the patients who did not. The overall accuracy of the CT interpretations to help establish diagnosis was 65% (36 of 55). When obstructions were classified into low- and high-grade partial obstruction, CT results could be used to identify correctly 81% (17 of 21) of high-grade SBOs and 48% (12 of 25) of low-grade SBOs. The procedure yielded two false-positive and 13 false-negative results for patients with low-grade obstruction, revealed masses in all six cases with tumor-related obstruction, and helped predict the correct cause in all true-positive cases.