Carbon dioxide in angiography to reduce the risk of contrast-induced nephropathy.

In the 1970s, Hawkins pioneered the intra-arterial use of carbon dioxide gas for high-risk patients who were allergic to iodinated contrast material and for those with renal failure. With the advent of digital subtraction angiography in 1980, reliable imaging of "low-density" CO(2) contrast agent became available. Subsequently, with the addition of high-resolution of digital subtraction angiography, stacking software (adding multiple images), tilting tables and a reliable, user-friendly delivery system, CO(2) imaging has become nearly comparable to and, in some cases, superior to that of iodinated contrast media. It is the only safe contrast agent for patients in renal failure, which is extremely important in view of the increasing incidence of diabetes and complexities of interventional procedures. The low viscosity of CO(2) not only improves the sensitivities of several diagnostic procedures but may afford advantages for several interventional procedures.