Thin-section CT in the examination of cervical disc herniation. A prospective study with 1-mm axial and helical...

The aim of the investigation was to determine whether thin-section high-resolution CT imaging could replace MR imaging and/or myelography in preoperative evaluation of radiculopathy and/or myelopathy.

A total of 120 patients, referred for cervical myelography (n=107) or MR imaging (n=13), were further examined with 1-mm non-contrast CT of the suspected disc space, including at least the next cephalic and caudal interspaces. Thirty-seven patients underwent Cloward's operation, at which 32 were found to have disc herniation.

The sensitivities of CT (n=37), myelography (n=29) and MR imaging (n=8) were 66%, 84%, and 86%, respectively. The corresponding figures for false-positives were 8%, 10%, and 13%. Artefacts caused by wide shoulders in the 1-mm CT images were estimated to have contributed to a false-negative finding in 8 cases. The remaining 3 false-negatives were retrospectively considered evaluation errors. The true-positive CT findings usually presented with a local disc bulge measuring over 80 HU in density. Local ligamentous hypertrophy presented an indistinguishable finding in 3 cases, yielding false-positive CT findings.

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.