Radiology in intestinal ischemia. Plain film, contrast, and other imaging studies.

Because plain films are usually normal or nonspecific in both colonic and acute mesenteric ischemia, they are not diagnostically helpful. The barium enema is the most useful radiographic examination in the diagnosis of colonic ischemia, and a double-contrast study will show abnormalities in almost all cases. Findings specific for colonic ischemia characteristically change with time. Thumbprinting is the most diagnostic finding; it is seen early in the course of the disease and usually resolves or is replaced within 1 or 2 weeks by an acute ulcerating colitis pattern. The latter may heal over months or go on to stricture formation or a persistent colitis. Nonspecific abnormalities can also be identified on CT and ultrasound, but the incidence of the findings with colonic ischemia is not known. Plain film findings occur late in the course of acute mesenteric ischemia and thus cannot be relied on for the diagnosis, although they may be useful in excluding other conditions. When acute mesenteric ischemia is suspected, angiography should be performed, but CT, ultrasound, and, perhaps, MR imaging may contribute to the diagnosis.