Bradley Spieler MD, Presenter: Nothing to Disclose

James S. Babb PhD, Abstract Co-Author: Nothing to Disclose

Michael Macari MD, Abstract Co-Author: Nothing to Disclose

Differentiating sigmoid from cecal volvulus can be challenging at CT. We sought to determine if the location of the mesenteric twisting can be used to help differentiate these entities.

IRB approval was obtained. From a radiology data base we identified 31 patients who underwent MDCT and had confirmed colonic volvulus. 23 had IV contrast and 8 underwent imaging without IV contrast. All patients received oral contrast. The mean age was 64.6 and the range was 23-96. The subjects included 15 with confirmed cecal volvulus and 16 with sigmoid volvulus. Axial and coronal images were retrospectively evaluated on PACS by two reviewers in consensus to determine if the mesenteric twist was to the right of midline or in the midline or slightly to the left. The imaging finding of the location of the twist was correlated with whether the patient had cecal or sigmoid volvulus. Fisher’s exact test was used to determine if there was an association between the location of the twist (right versus mid-left) and the location of the colonic volvulus (cecal versus sigmoid).The Blyth-Still-Casella procedure was used to derive an exact 95% confidence interval for the percentage of times the location of the twist can be expected to accurately diagnose a volvulus as cecal or sigmoid.

According to Fisher’s exact test, there was a highly significant association (p<0.0001) between the location of the twist (right versus mid-left) and the location of the colonic volvulus (cecal versus sigmoid). Using the location of the twist as a predictor of whether the volvulus was cecal or sigmoid provided a correct diagnosis for 93.3% (14/15) of the cases with cecal volvulus and 100% (16/16) of the cases with sigmoid volvulus, yielding an overall diagnostic accuracy of 96.8% (30/31). The results indicate that you can be 95% confident that twist location will accurately diagnosis 69.8 to 99.7% of cases with cecal volvulus, 80.25 to 100% of cases with sigmoid volvulus and will accurately discriminate cecal from sigmoid volvulus for between 83.9 and 99.8% of cases.

The location of the mesenteric twist is a highly accurate finding in discriminating cecal from sigmoid volvulus.

If mesenteric twisting (whirling) is noted in the right abdomen the findings are consistent with cecal volvulus, if it is noted in the midline or to the left, a sigmoid volvulus is present.

Spieler, B, Babb, J, Macari, M, Can the Location of the Mesenteric Twist (Whirl) Be Used to Differentiate Sigmoid from Cecal/Ascending Colon Volvulus?.  Radiological Society of North America 2009 Scientific Assembly and Annual Meeting, November 29 - December 4, 2009 ,Chicago IL. http://archive.rsna.org/2009/8002284.html