Carbon Dioxide Angiography

The algorithm for patients with renal insufficiency who require vascular imaging has recently changed in my hospital. Previously, the majority of these patients underwent magnetic resonance angiography (MRA) or occasionally computed tomographic angiography after prescan hydration and sodium bicarbonate infusion. Although we have used carbon dioxide (CO 2 ) for many years, with the advent of nephrogenic systemic sclerosis and its unclear relationship to MRA contrast agents, we are increasingly using CO 2 as a contrast agent for both diagnosis and to guide therapy. CO 2 has been used for > 30 years. It is not nephrotoxic or hepatotoxic and is nonallergenic. It is also quite inexpensive compared with other contrast agents.