Comparative neurotoxicity of angiographic contrast media

The neurotoxic effects in cerebral angiography of three iodinated ionic contrast media, nonionic iopamidol, 25% mannitol, and saline controls were compared in 25 rabbits. Diatrizoate sodium meglumine was the most toxic agent, followed by diatrizoate and meglumine, iothalamate meglumine, and mannitol in terms of blood-brain barrier (BBB) disruption and coupled perfusion decline. HIPDm distribution was more sensitive than trypan blue extravasation for monitoring brain dysfunction. Iopamidol and saline controls exhibited no visual BBB breakdown or alteration in regional uptake of I-125 HIPDm, confirming the safety of nonionic iopamidol as compared with presently used ionic contrast media.