Visualization of the portal circulation is one of the most important aspects of celiac and mesenteric arteriography. In the course of performing angiography immediately after epinephrine injections for better tumor delineation (9), we noted that arteriograms obtained five to ten minutes after epinephrine invariably gave portograms improved over those obtained without epinephrine. On this basis, a technic for portal visualization was developed and applied in over 90 clinical examinations. Technic A radiopaque polyethylene catheter (BD RPX 054) is positioned in either the celiac axis or superior mesenteric artery. A solution of 1 microgram of epinephrine per milliliter of saline is prepared. Sixteen to twenty-four milliliters of this solution is then infused through the catheter over a two-minute period. An immediate post-epinephrine arteriogram is obtained if indicated. Delayed postepinephrine arteriography is performed seven to ten minutes after conclusion of the epinephrine infusion, 40 to 60 ml of meglumine iothalamate 60 per cent (Conray 60) being injected in the superior mesenteric artery, or 50 to 70 ml in the celiac axis. The usual injection time is five to six seconds. However, the fastest injection rate is used at which reflux of contrast material or recoil of the catheter into the aorta does not occur. Serial films are obtained over a twenty-second period. Results The initial clinical impression of improved portal visualization after epinephrine was confirmed in animal studies and regularly demonstrated in patients (Fig. 1). In many instances the density of the portal venous system was almost that of a direct splenoportogram. Displacement, invasion, and occlusion due to tumor could be well shown (Figs. 2 and 3). Even in patients with marked portal hypertension, diagnostically adequate visualization of the portal circulation was achieved in almost every case (Fig. 4). The portal flow was accelerated. The time of first appearance of contrast material in the splenic vein was reduced from six to four seconds, and in the portal vein from seven to five seconds after the start of injection. Optimal opacification of the portal vein occurred at fifteen seconds in the control studies and at eleven seconds in the injections after epinephrine. No consistent changes in the size of the arteries or veins were found. The spleen was reduced in length after epinephrine by an average of 1 cm, and the maximum blush was greater and appeared earlier. A dense hepatogram was observed during the portal phase. An interesting observation was the frequently increased opacification of the cystic arteries and gallbladder wall in the films obtained after epinephrine (Fig. 5). The mucosal blush of the small bowel in superior mesenteric artery injections was also more prominent. Discussion Selective arterial portography has emerged as the safest method of visualizing the portal circulation (11). Its use in the evaluation of portal hypertension is now well established (3, 6).