In order to compare the diagnostic accuracy of CT scan and myelography, a series of 137 patients with herniated lumbar disc was retrospectively analyzed matching the surgical findings with the images obtained by both diagnostic techniques. There were 76 h e r n i a t e d d i s c s at the L5-S1 l e v e l and 61 at the L4-L5. Preoperatively, 99 patients were assessed by CT scan and 77 by mielography. In 39 cases, both techniques were performed. The diagnostic accuracy, quantified by the percentage of "true positive" results was similar in both techniques: 89% in CT scan and 90% in mielography. In 12 of the 39 patients explored by both CT scan and myelography, the results were discordant. "False negative" cases were not found using CT scan. In conclusion, both CT scan and myelography provide equal high diagnostic accuracy for lumbar herniated disc. However, CT scan has become the primary diagnostic tool because of several advantages, such as the confort for the patients and the lack of adverse reactions.

In order to compare the diagnostic accuracy of CT scan and myelography, a series of 137 patients with herniated lumbar disc was retrospectively analyzed matching the surgical findings with the images obtained by both diagnostic techniques. There were 76 h e r n i a t e d d i s c s at the L5-S1 l e v e l and 61 at the L4-L5. Preoperatively, 99 patients were assessed by CT scan and 77 by mielography. In 39 cases, both techniques were performed. The diagnostic accuracy, quantified by the percentage of "true positive" results was similar in both techniques: 89% in CT scan and 90% in mielography. In 12 of the 39 patients explored by both CT scan and myelography, the results were discordant. "False negative" cases were not found using CT scan. In conclusion, both CT scan and myelography provide equal high diagnostic accuracy for lumbar herniated disc. However, CT scan has become the primary diagnostic tool because of several advantages, such as the confort for the patients and the lack of adverse reactions.