CT Whirl Useful in Managing Small-Bowel Obstruction

You’ve seen it—the CT whirl sign when imaging the small bowel. But have you considered its significance in predicting patient outcome in the management of small-bowel obstruction?

A study reported in the September 2008 issue of the American Journal of Roentgenology looked at the CT whirl and reported some interesting findings.

They found that a patient with a CT whirl was approximately 25 times more likely to require surgery to treat a small-bowel obstruction.

The study was a retrospective analysis comprised of 194 patients who had a diagnosis of small-bowel obstruction made with radiologic criteria and follow-up information.

The images were evaluated for the presence of a CT whirl sign, which was defined as twisting of the bowel greater than 90° surrounding a central soft-tissue density of mesentery and vessels.

Of the 40 patients who had the CT whirl, 32 had small-bowel obstruction that required surgical treatment for a positive-predictive value of 80%. The other eight received successful medical treatment.

The odds ratio between the presence and absence of the whirl sign and predicting small-bowel obstruction requiring surgery was approximately 25.Therefore, a patient with a CT whirl sign and small-bowel obstruction is 25 times more likely to require surgery than a patient without the sign.

We should all keep this in mind when observing the CT whirl, as these results are useful in demonstrating the impact of finding a CT whirl sign in the management of patients with clinical and radiologic evidence of small-bowel obstruction.

Note, however, that one of the limitations to consider is that it was not determined how often whirl sign occurred in patients who did not have a diagnosis of small-bowel obstruction.

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Reference: Duda JB, Bhatt S, Dogra VS. Utility of CT Whirl Sign in Guiding Management of Small-Bowel Obstruction. AJR 2008; 191 (September): 743–747.