[Computed tomography in lumbar degenerative disease].

We reported the 18 patients which underwent surgical exploration and reviewed these CT findings. Method. All CT scans were obtained on Somatom II, high resolution CT scanner, with the patient in the supine position. A lateral localizer image (Topogram) was used to select the appropriate intervertebral disk space. The slice thickness was 4 mm. Results. CT findings in lumbar degenerative diseases include bony canal stenosis (central canal stenosis, narrowed lateral recess), soft tissue abnormalities (herniated nucleus pulposus, bulging annulus, hypertrophy and/or ossification of ligamentum flavum, no delineation of nerve root in lateral recess), and spinal instability (spondylolisthesis, vacuum phenomenon). The above three factors contribute to narrowing of spinal canal. No delineation of nerve root or soft tissue replacement of epidural fat in lateral recess suggests that the nerve root may be compressed by some factors. Herniated nucleus pulposus may cause nerve root compression with or without canal stenosis. Conclusion. This study revealed that the CT findings correlated closely with the surgical findings and the site of nerve root compression could be determined.