Computed tomography of the normal mesentery.

Thirty patients were studied to evaluate the CT appearance of the normal mesentery and its vasculature. Mesenteric vessels were identified by determining their relations to segments of the small bowel and colon in the 30 patients. Jejunal and ileal branches supplying small bowel were identified in all patients. The ileocolic and right colic branches of the ascending colon were identified in 27 and 26 patients, respectively; middle colic vessels were identified in 29 patients. Left colic branches were identified in only 14 patients; sigmoid branches were identified in 23 patients. The vessels showed a characteristic wavy appearance as they coursed through mesenteric fat. The average attenuation of the mesenteric fat was -117.4 +/- 7.9 H. Normal lymph nodes were not routinely identified within the mesentery. Various pathologic processes altered the normal appearance of the components of the mesentery.