Elimination of aqueous myelographic contrast media from the subarachnoid space.

Elimination of aqueous contrast media from the lumbar subarachnoid space was measured. Iodine concentrations in serum and cisterna magna cerebrospinal fluid were studied in animals undergoing myelography with metrizamide, iocarmate, Iopamidol, or P-297. We found that all four contrast media were eliminated rapidly into the serum and urine, and transported slowly into the basal cisterns.