Figure 8a. Acute mesenteric ischemia in a 56-year-old woman with severe abdominal pain. The patient had undergone Whipple surgery for pancreatic cancer 5 days earlier. (a) Axial multi-detector row CT scan demonstrates thrombosis of the superior mesenteric vein (arrow). (b) Axial CT scan obtained inferior to a demonstrates thickened small bowel loops with a halo appearance, findings that are compatible with ischemia.