Colitis

This paper determines whether any of the findings of colitis observed on CT scans are useful in differentiating colitides of different etiologies. The authors reviewed the CT scans of 102 patients with documented acute or chronic colitis and thickening of the colon wall at CT. Features evaluated were distribution of disease, bowel wall thickness and density, pericolonic mesenteric abnormalities, and associated findings including small-bowel involvement lymphadenopathy, and abscesses. The mean colonic wall thickness in Crohn colitis (11.0 mm ± 2) was significantly greater than that in ulcerative colitis (7.9 mm ± 2.4) (P < .001) and all other colitides (P < .05), although overlap was observed. Submucosal fat deposition was present significantly more frequently in ulcerative colitis (13/22) than in Crohn colitis (3/34) (P < .001). This finding was not observed in the acute colitides. Fibrofatty mesenteric proliferation and the presence of an abdominal/pelvic abscess were findings associated exclusively with Crohn colitis (10/34). Small-bowel wall thickening was significantly more frequent in graft-versus-host disease (110%) and Crohn colitis (56%) than in all other colitides