LUMBAR HERNIATED DISK DISEASE - COMPARISON OF MRI, MYELOGRAPHY AND POST-MYELOGRAPHIC CT SCAN WITH SURGICAL FINDINGS

One hundred eighty patients with suspected lumbar disk disease were ev aluated preoperatively with magnetic resonance imaging (MRI), myelogra phy, and post-myelogram computerized tomography (CT) scan. Sixty patie nts underwent surgery on 102 disk levels, allowing for anatomic confir mation of the diagnosis. Eight negative explorations were performed. T he correlation between preoperative interpretations of each test and t he observed surgical findings was analyzed statistically. Based on thi s analysis, MRI accurately predicted the operative findings in 98 of 1 02 disk levels (96%), while the accuracy of myelography (81%) and post -myelogram CT scan (57%) was significantly less. When myelography and CT scan were utilized jointly, the accuracy was 84%, a significant imp rovement over either test alone, as a diagnostic modality. There was o nly one false positive MRI study in the evaluation of lumbar herniated disk. The results of this study reflect that MRI is a clinically supe rior diagnostic test in the evaluation of patients with suspected lumb ar disk herniation, and that it should be the diagnostic study of choi ce when available. Its noninvasive nature, multiplanar capabilities, a nd the lack of ionizing radiation are particularly desirable for patie nt and physician.