Findings-The contrast enhanced CTs show air in the bowel wall and portal venous system, which is classic for bowel ischemia and necrosis.
-Note that some of the gas collections remain in the dependent portion of the bowel i.e. they are not intralumenal, but are trapped in the bowel wall.
Discussion
Interruption of blood flow to the bowel can result in bowel ischemia and necrosis. The CT findings include air in the bowel wall aka pneumatosis coli, mesenteric or portal venous gas, lack of bowel wall enhancement, increased enhancement of the thickened bowel wall, and/or bowel obstruction.
http://eradiology.bidmc.harvard.edu/Classics/item.aspx?section=Emergency+Radiology&labelpk=33f0adab-853f-4010-a0e2-0756b3f1eac5&pk=8c961ba5-9a67-48e9-b8ca-3f1c1dd3b6e2
