Advantages of supplementary CT in myelography of intraspinal masses.

Computed tomographic (CT) myelography subsequent to nonionic water-soluble contrast medium myelography has provided additional diagnostic information for evaluating intraspinal mass lesions. In 20 patients thus studied, there were eight intramedullary tumors, eight intradural extramedullary masses, and four extradural neoplasms. In intramedullary tumors CT enabled more precise delineation of the extent and location of expansion of the spinal cord. In intradural and extradural tumors, rotation and compression of the spinal cord as well as bony and paraspinal soft-tissue changes were more accurately demonstrated in the axial plane. When a complete block was present, the greater contrast sensitivity of CT permitted visualization beyond the level of the block. Histologic prediction is not feasible by CT myelography except for hyperlucent lipoma. CT can provide useful supplemental information to conventional metrizamide myelography.