Complications in cerebral angiography. A comparison between the non-ionic contrast medium iohexol and meglumine metrizoate (Isopaque Cerebral).

Cerebral angiography was performed in 100 patients in order to study the frequency of adverse effects and complications with a new non-ionic contrast medium, iohexol, compared with an ionic medium, meglumine metrizoate. The study was performed as a double blind clinical trial. Iohexol was better tolerated than meglumine metrizoate, since more patients experienced the injections as painful and unpleasant with metrizoate than with iohexol. However, the subjective adverse effects were minor with both contrast media. There was no statistically significant difference in the frequency of more serious side effects. Transient hemiparesis was seen in two patients who prior to the angiography had suffered from numerous similar attacks per day and in one patient in whom a nearly occluded internal carotid artery was occluded during the examination. These complications occurred in the iohexol group, but are more likely to be due to thromboembolism than to contrast medium toxicity.