The hazards of myelography.

The history of myelography and reactions to various contrast media is reviewed. Air is completely absorbed without producing long-term side effects. Lipiodol and Pantopaque are not absorbed and residual medium in the spinal canal can cause arachnoiditis. Other agents as Diodrast and Thorotrast never gained widespread acceptance. The water-soluble Dimer-X and Conray 60 have come into prominence but they are not totally without reactions. Recently a new water-soluble nonionic contrast medium has been developed in Norway. Metrizamide (Amipaque) has the same overall density as other water-soluble media but produces fewer reactions.