Digital subtraction angiography of the portal venous system.

Venous-phase arteriography after celiac or superior mesenteric artery injection is the most common technique used to demonstrate portal venous anatomy, flow direction, and portal systemic shunts. Large-volume contrast material injections and intraarterial vasodilators or balloon occlusion technique are required for optimal examinations using film-screen recording. A technique for performing venous-phase arteriography with digital subtraction imaging after celiac and superior mesenteric artery injection is described. The major advantage of intraarterial digital subtraction technique in comparison to film-screen recording is sensitivity to intravascular iodine with a consequent reduction in contrast material load and examination time. Technical success is limited only by motion artifact and should approximate the 80%-90% figure achieved for intravenous digital subtraction angiography of the aortorenal vessels.