Discrepancy between metrizamide CT and myelography in diagnosis of cervical disk protrusions.

With the advent of the relatively safe water-soluble contrast medium metrizamide, cervical myelography followed by metrizamide computed tomography (CT) can be performed easily. Sixteen patients with cervical disk protrusions (eight central and eight posterolateral) were studied by both procedures to evaluate the diagnostic value of each. In 75% of the posterolateral disk protrusions, myelography was as diagnostic as metrizamide CT. Metrizamide CT was definitely superior to myelography in 75% of the central disk protrusions with delineation of compressed cord. Information provided by metrizamide CT is detailed enough to allow the selection of a definitive anterior approach without delay.