Differentiating sigmoid diverticulitis from carcinoma on CT scans: mesenteric inflammation suggests diverticulitis.

OBJECTIVE

The purpose of this study was to analyze the usefulness of two specific CT signs of sigmoid mesenteric inflammation (fluid at the root of the mesentery and vascular engorgement) for identifying and differentiating sigmoid diverticulitis from carcinoma.

MATERIALS AND METHODS

CT scans of 69 patients with surgically proved sigmoid diverticulitis were retrospectively reviewed and compared with CT findings in 29 patients with surgically proved sigmoid carcinoma. Two specific patterns of inflammation of the sigmoid mesentery were analyzed: fluid at the root of the sigmoid mesentery and engorgement of the sigmoid mesenteric vessels.

RESULTS

The CT findings were present more often in patients with sigmoid diverticulitis than in those with carcinoma (p < .001). Fluid at the base of the mesentery had a sensitivity, specificity, and positive predictive value for diverticulitis of 36%, 90%, and 89% respectively. Vascular engorgement alone had a sensitivity, specificity, and positive predictive value of 29%, 100%, and 100%, respectively.

CONCLUSION

Our results suggest that CT findings of fluid at the root of the mesentery and vascular engorgement are useful in distinguishing sigmoid diverticulitis from carcinoma of the sigmoid.