Cerebral angiography with gaseous carbon dioxide CO2.

Large quantities of gaseous carbon dioxide CO2 were rapidly injected into the ascending aorta or common carotid artery of 14 dogs. Good filling of the arteries and intracranial veins was documented by cineangiography or digital subtraction angiography. No adverse effects occurred as a result of this procedure: the electroencephalogram showed no changes throughout the experiments and the dogs were neurologically normal for up to 6 months of follow-up. Further investigation of carbon dioxide as an arterial and cerebrovascular contrast agent is justified based on these results.