CEREBRAL angiography has proved invaluable in the diagnosis of certain cerebral lesions. The increasing number of patients subjected to this procedure necessitates an awareness of its hazards.Gross,1 in 1940, first used iodopyracet (diodrast\s=r\; the diethanolamine salt of 3,5-diido-4-pyridone-N-acetic acid) for cerebral angiography in this country. He reported no alterations in the brains of dogs subjected to angiography with 35%, 50%, and 70% solutions of this medium. Convulsive seizures, however, occurred in 3 of 10 human subjects in whom he used a 70% solution. Gross recommended the use of a 50% solution, which he believed safe. He reported inadequate visualization with the 35% solution. Kristiansen and Cammermeyer 2 found no abnormality in the brains of 13 rabbits that had received 17 injections of 35% iodopyracet.Broman and Olsson,3 however, showed that contrast media of the iodopyracet type "are capable of causing a damage solely of the BBB (blood-brain barrier), the demonstration of which requires the application of a special technique." They used trypan blue, to which thé cerebral vessels are normally impermeable. If the vascular permeability is impaired, however, the trypan blue will escape into and stain the surrounding tissue. Using rabbits, cats, and guinea pigs, they showed that the iodopyracet compounds in concentrations of 35 to 70% altered the per¬ meability of the cerebral blood vessels. In the cases 4 in which the injury was rather severe edema and punctate hemorrhages occurred." surg. 8:435-440 [July] 1951) have published the results of their interesting experiments since this report was prepared. These authors used a combined method of indicator-dye injection and electroencephalography to demonstrate functional and structural changes in rabbits after cerebral angiography with iodopyracet injection.
