ABSTRACT
We have used CO2 for lower extremity angiograms since 1970 in primarily “high risk”
patients. In the past, CO2 was used most frequently for aortograms and runoffs, primar-
ily in patients with allergies and renal failure. In approximately 90% of patients, the
entire runoff, including the feet, can be imaged solely with CO2, and with addition of
small amounts of iodinated contrast, the feet can be imaged in almost 100% of the
patients. The buoyancy and low viscosity of CO2 occasionally provides better filling
than iodinated contrast of collateral arteries (Figs. 1 and 2), tumors, arteriovenous (AV)
shunting, and bleeding sites.
