Ischemic colitis: spectrum of CT findings, sites of involvement and severity.

To summarize the frequency of findings on IV contrast, enhanced computer tomography (CT) in 335 patients with pathologically proven ischemic colitis (IC) determine the most frequent locations and patterns of involvement and establish the correlation of these findings with the severity of IC. 231 patients were excluded for not having a concomitant CT or for having underlying comorbidities. 104 cases were analyzed. Scans were evaluated for abnormal wall enhancement (AE), bowel wall thickening (BWT), bowel dilatation (DIL), mesenteric fat stranding (FS), venous engorgement (VE), pericolonic free fluid (FF), and pneumatosis (PN) and portomesenteric venous gas. Segmental versus pancolonic involvement was noted. Severity was determined by histopathology criteria. Data obtained are as follows: female to male incidence, 69 % (70) vs. 31 % (34); average age, 64.5; and positive CT, 102/104 (98.1 %). The most frequent findings include FS (88 %), BWT (88 %), and AE (82 %) regardless of severity of involvement. Statistically significant increased risk ratio and likelihood of severe ischemia for PN, DIL, and FF individually. BWT, DIL, FS, FF, VE, and PN together have a probability for severe IC of 91.8 %. A correlation between fewer findings and milder IC was found (R (2) = 0.6771). The most frequently involved segments: descending (64 %) and sigmoid colon (54 %). Splenic flexure (SF) was infrequently involved (n = 8, 7.84 %). Females had two times higher incidence of IC. The most frequent CT findings in IC are FS, BWT, and AE regardless of the severity. PN is suggestive of severe IC. Segmental involvement is the predominant pattern. The distal colon is more frequently involved. SF contrary to the conventional literature is not disproportionately involved in IC.