Sites of cerebrovascular injury induced by radiographic contrast media

The object of this study was to determine the type of cerebral vessel affected by injection of radiopaque contrast agents used in cerebral angiography. Seventeen rabbits were prepared surgically for a left intracarotid injection of methylglucamine iothalamate (Conray 60) or methylglucamine diatrizoate (Reno-M-60). Extravasations of the tracers, Evans blue and horseradish peroxidase, occurred in the left half of the brain and occasionally in the right half. Within those areas of blood-brain barrier breakdown, the frequency of leakage was 60% for arterioles, 25% for venules, and 12% for capillaries. The leakage appeared to be primarily intercellular, rather than intracellular. This study provides evidence that greater blood-brain barrier alterations occur in arterioles and venules than in capillaries following cerebral angiography.