[Prolapse of the lumbar vertebral disk--correlation of CT and myelographic findings with surgical findings].

Side by side with myelography, computed tomography is growing in importance as far as the diagnosis of the lumbar compression syndrome is concerned. From May 1980 to the end of April 1982, the authors employed at the Cologne University Clinic of Orthopaedics in 176 patients operated either for the first time or several times, myelography alone in 54 cases, and myelography combined with computed tomography in 98 cases, whereas computed tomography alone was used 24 times, in each case for the purpose of preoperative diagnosis. An epicritical analysis of the two last-named groups of examinations, basing on the findings made as a result of the operation, showed that computed tomography was superior in respect of the accuracy in determining the level and affected side of the compression. Two CT examinations only could not be utilised for technical reasons. Nine false-positive or false-negative cases (plus two examinations which were useless for technical reasons) were seen among the 98 myelographies of the patient group in question. Besides the equivalent information given by computed tomography in respect of the level and side of the compression, CT supplies additional information regarding constriction of the vertebral canal, defined osseous stenoses, preference for a particular side and site of prolapsed disk tissue, and on the cause of the compression in case there is a considerable stoppage of contrast medium. Computed tomography is better suited than myelography in the immediate postoperative phase for follow-up examinations which are aimed at differentiating renewed prolapses, haemorrhages, or cicatrised changes. Provided there is enough capacity for examination, it seems possible that the noninvasive computed tomography will eventually replace invasive myelography as a routine examination method in case of relevant indications.