What is carbon dioxide angiography? Cardiology Basics 

Carbon dioxide angiography is done using carbon dioxide injection into the blood vessel. Usually iodine containing radiocontrast dyes are injected into the blood vessels and continuous X-ray imaging done, to obtain angiograms.
Contrast material is needed to visualize the blood vessel separately from the other body tissue. But usual iodinated radiocontrast dyes have a potential risk of causing acute kidney injury. This is more so in those with already impaired renal function. It is in this situation that carbon dioxide angiography is usually considered.