THE ROLE OF NONIONIC MYELOGRAPHY IN THE DIAGNOSIS OF LUMBAR DISC HERNIATION

RATIONALE AND OBJECTIVES. The accuracy and safety of nonionic myelogra phy, unenhanced computed tomography (CT), and magnetic resonance (MR) in the diagnosis of lumbar disc herniation are reviewed. The comparati ve costs of these tests are also considered. METHODS. The accuracy of imaging tests that diagnose disc herniations was established by conduc ting a Medline search between 1985 and 1992. The morbidity associated with these tests are less formally established from selected articles. Finally, the mediocre reimbursement rates of these tests are reviewed . RESULTS AND CONCLUSIONS. The evolution of nonionic contrast media fr om the first to the second generation has been accompanied by a notabl e decrease in adverse reactions. Although nonionic myelograms are now better tolerated by patients, noninvasive imaging with CT and MR imagi ng has become as accurate as or more accurate than lumbar myelography, and should replace it as a screening test. Computed tomography may ha ve advantages over MR imaging when issues of availability and cost are considered. In contrast to lumbar myelography, CT myelography may con tinue to be a useful method for clarifying ambiguous results of noninv asive tests. The morbidity associated with CT myelography can be minim ized by using low doses of a nonionic agent, keeping the patient well hydrated, and using a small lumbar puncture needle. The incidence of a dverse reactions can be expected to decrease further as new nonionic d imers become clinically available.