Comparative double-blind investigation of meglumine metrizoate, metrizamide, and iohexol in carotid angiography.

Abstract

The new nonionic contrast medium iohexol (Omnipaque) was compared with its predecessor metrizamide (Amipaque) and with the conventional ionic medium meglumine metrizoate (Isopaque Cerebral) in carotid angiography using a double-blind crossover technique. The results indicated that iohexol and metrizamide caused less discomfort than the ionic medium. The circulatory effects of the three media were generally mild, and the diagnostic effectiveness was comparable when the iodine concentration was kept in the range of 280-300 mg I/ml.