Although the SMA orifice is normally enhanced, CT scans caudal to this level (not shown) reveal acute superior mesenteric artery occlusion. Note diminished enhancement of thin bowel walls (white arrowheads) as compared to normal duodenum (black arrowhead) and pneumatosis intestinalis (white arrows). Resection of small bowel and right colon showed coagulative necrosis. This 86 year-old female patient died of sepsis 4 days later. SMA = superior mesenteric artery