Fig. 1

Contrast-enhanced multidetector computed tomography study. a At the level of the pancreatic head (P): retro-arterial course (arrowheads) of the transverse colon (T) dorsal to the mesenteric vessels. Note the inverted relationship of the superior mesenteric vein (V) and superior mesenteric artery (white arrow) and the aplasia of the pancreatic uncinate process. The duodenum (D) crosses from right to left anterior to the pancreas and the mesenteric vessels. b At the level of the posterior-inferior margin of the right hemiliver: retro-arterial course (arrowheads) of the proximal jejunum (J) from left to right, sandwiched between the superior mesenteric vessels and the aorta. Note the aberrant position of the cecum and the ileocecal valve (*) close to the midline. c Coronal reformatted image: normal position of the left colic flexure (white arrow) and the descending colon (DC). The relationship between the transverse colon (T) and the jejunum (J), both in a retro-arterial position, is demonstrated. Several small bowel loops are noted in the lower abdomen