THIN-SECTION CT IN THE EXAMINATION OF CERVICAL DISC HERNIATION - A PROSPECTIVE-STUDY WITH 1-MM AXIAL AND HELICAL IMAGES

Purpose: The aim of the investigation was to determine whether thin-se ction high-resolution CT imaging could replace MR imaging and/or myelo graphy in preoperative evaluation of radiculopathy and/or myelopathy. Material and Methods: A total of 120 patients, referred for cervical m yelography (n = 107) or MR imaging (n = 13), were further examined wit h 1-mm non-contrast CT of the suspected disc space, including at least the next cephalic and caudal interspaces. Thirty-seven patients under went Cloward's operation, at which 32 were found to have disc herniati on. Results: The sensitivities of CT (n = 37), myelography (n = 29), a nd MR imaging (n = 8) were 66%, 84%, and 86%, respectively. The corres ponding figures for false-positives were 8%, 10%, and 13%. Artefacts c aused by wide shoulders in the 1-mm CT images were estimated to have c ontributed to a false-negative finding in 8 cases. The remaining 3 fal se-negatives were retrospectively considered evaluation errors. The tr ue-positive CT findings usually presented with a local disc bulge meas uring over 80 HU in density. Local ligamentous hypertrophy presented a n indistinguishable finding in 3 cases, yielding false-positive CT fin dings. Conclusion: Conventional thin-section CT is considered a usable alternative for the evaluation of suspected cervical disc herniations in selected patients. Stocky patients with wide shoulders and a short neck are not suitable candidates, even when new generation equipment is available.