The prolapsed intervertebral disc - The high-intensity zone with discography correlation

Study Design. The study compared the presence of the high-intensity zone on magnetic resonance imaging with the results of awake discography. Objectives. To see if there was a correlation between the results of awake discography and the presence of a high-intensity zone on magnetic resonance imaging. Summary of Background Data. The evaluation of discogenic pain has proved to be somewhat elusive. Recent studies have indicated the high-intensity zone as being highly sensitive in the diagnosis of the painful discogenic segment. The present study was designed to investigate whether the presence of a high-intensity zone is associated with a concordant pain response on awake discography. Methods. Magnetic resonance images were obtained in 29 patients with low back pain with and without radiculopathy. Consecutive patients were considered for surgical intervention after failing to respond to conservative treatment. The presence of a high-intensity zone was specifically looked for within the posterior anulus. Each patient subsequently underwent awake discography with computed tomography. Computed tomography was classified according to the Dallas Discogram Scale and the presence of a concordant pain response. Chi-square analysis was used to calculate the presence of a high-intensity zone versus disc disruption and the correlation of high-intensity zone and concordant pain response. Results. There was no statistically significant correlation between the presence of a high-intensity zone and a concordant pain response at any level. The high-intensity zone was, however, never seen in a morphologically normal disc. Conclusions. Although the high-intensity zone is present within the posterior anulus of some abnormal discs, it is not necessarily associated with a concordant pain response.