Primary aortoduodenal fistulas in minimally aneurysmal aortas: imaging diagnosis.

We report on the utility of computed tomography (CT) in making the diagnosis of primary aortoduodenal fistulas in two cases presenting with massive gastrointestinal hemorrhage. In both cases, the clinical presentation was insidious, no pulsatile abdominal mass was palpated, and endoscopy findings were inconclusive. CT showed minimally aneurysmal aortas communicating with larger areas of contained rupture and pseudoaneurysm stretching adjacent small bowel.