During the last 3 years 58 digital subtraction angiographies in 54 patients were performed using either CO2 alone or in combination with non-ionic iodinated contrast medium. The indication for CO2 angiography was a previous severe adverse reaction to iodinated contrast media (in 8 patients, 10 studies), patients with impaired renal functions or preexisting renal failure (21 patients indicated for peripheral lower leg angiography and 4 patients with hepatorenal syndrome referred for TIPS procedure). Another 13 patients with retrograde wedged hepatic portography and 6 patients with superior mesenteric angiography indicated for lower gastrointestinal bleeding were included in this study. Using CO2 as a contrast agent the total dose of iodinated contrast media can be lowered by 50% in patients with preexisting renal function impairment. The study was done by using only CO2 in patients with a high risk of allergic reaction. Wedged hepatic vein CO2 - based portal vein opacifications were successful in 83%. No case of extravasation was revealed in 6 patients with technically successful superior mesenteric angiography performed for lower gastrointestinal blee- ding. The use of CO2 as an intravascular contrast agent is technically more demanding than iodinated contrast medium imaging. Therefore it was used only in cases where its safety (no nephrotoxicity and hypersensitivity) outweighed its disadvantages. In the wedged hepatic vein CO2 - based portal vein opacification was superior to that with iodinated contrast media.

        Key words: carbon dioxide - contrast medium, comparative study - digital subtraction angiography