CT and MRI features of bowel ischemia
On CT and MRI, one may see bowel wall thickening; mural hypoattenuation related to submucosal edema (sometimes with a “target” sign); mural hyperattenuation related to intramural hemorrhage; bowel dilation; perienteric or pericolic inflammatory fat stranding, fluid, or hemorrhage; ascites; absent, decreased, or increased mural enhancement; pneumatosis (gas bubbles in the bowel wall), mesenteric or portal venous gas, or pneumoperitoneum; and mesenteric arterial or venous occlusion
If bowel ischemia/infarction is suspected, one should assess the patency of the celiac artery, superior mesenteric artery, inferior mesenteric artery, portal vein, superior mesenteric vein, and inferior mesenteric vein. When the central superior mesenteric vessels are affected, the entire small bowel, along with the large bowel proximal to the distal third of the transverse colon, tends to be affected. When the central inferior mesenteric vessels are affected, the distal third of the transverse colon, the descending colon, and the sigmoid colon are generally involved.