Histological changes in the central nervous system following intraventricular administration of oil-soluble contrast media. An experimental study in the rat.

Following injections of iodophendylate (Pantopaque) in adult rats, the contrast medium was shown to be refrained in the dilated cerebral ventricles for at least 180 days. Histological examination revealed macrophages containing phagocytosed lipid on the ependymal lining of the ventricles, but there was no leukocytic reaction to retained or encysted contrast material. The macrophages were considered to be involved in the removal of iodophendylate. The irritative reaction in the normal central nervous system was limited, as opposed to the severe reactions previously reported in animals with inflammation of the brain and meninges.