Peripancreatic veins on thin-section (3 mm) helical CT.

OBJECTIVE: The purpose of this study was to evaluate thin-section helical CT for the frequency of visualization of the peripancreatic veins, the venous anatomy at the head of the pancreas, and variations of the venous anatomy. SUBJECTS AND METHODS: We performed 30-sec helical CT of the pancreas with one breath-hold and a 3-mm scanning collimation in 50 patients. The scan was started 60 sec after injection of an i.v. contrast medium at the rate of 2 ml/sec (total amount of contrast medium, 100 ml). The axial scan data were reviewed for the following information: the frequency of CT visualization of the peripancreatic veins (anterior superior pancreaticoduodenal vein, first jejunal vein, gastrocolic trunk, inferior mesenteric vein, left gastric vein, middle colic vein, posterior superior pancreaticoduodenal vein, right colic vein, and right gastroepipolic vein) and the anatomic relationship between the large portal venous system (portal vein, superior mesenteric vein, and splenic vein) and its tributaries. RESULTS: The frequency of visualization on CT of each vessel was gastrocolic trunk, 100%; right gastroepiploic vein, 100%; first jejunal vein, 96%; inferior mesenteric vein, 88%; left gastric vein, 80%; posterior superior pancreaticoduodenal vein, 72%; middle colic vein, 72%; right colic vein, 64%; and anterior superior pancreaticoduodenal vein, 50%. The anatomic relationship between the large portal venous system and its tributaries was as follows: The left gastric vein drained into the splenic vein-portal vein confluence (46%), into the splenic vein (32%), and into the portal vein (22%); the inferior mesenteric vein drained into the splenic vein (46%), the splenic vein-superior mesenteric vein confluence (25%), and the superior mesenteric vein (29%). The posterior superior pancreaticoduodenal vein drained into the portal vein above the splenic vein-portal vein confluence (mean distance, 0.3 cm). The middle colic vein, gastrocolic trunk, and first jejunal vein drained into the superior mesenteric vein below the splenic vein-portal vein confluence (mean distances of 2.4 cm, 3.0 cm, and 3.7 cm, respectively). CONCLUSION: Thin-section helical CT scans provide good visualization of the peripancreatic veins.