Diskography Can Help With Back Surgery Decision
In this article the use of diskography to identify the disc as the source of low back pain is reviewed. Diskography is done by inserting two needles into the disc. One goes into the center of the disc called the nucleus pulposus. The other punctures the outer covering of the disc called the anulus.

A liquid dye is slowly injected through the needles into these two areas. Pressure from the liquid on the disc causes pain if the disc is the problem. For this reason the test is considered to be "provocative." In other words, diskography provokes a painful response. The patient can only be mildly sedated so that pain is felt and reported.

The authors discuss the use of X-rays, CT scans, and MRIs in diagnosing disc problems. How these imaging studies compare with diskography is presented. Diskography is used when patients don't get better with conservative care and surgery is being considered.

It's a good tool to use because other imaging studies don't always show a problem when there is one. Likewise many patients with abnormal MRIs have no symptoms. The patient with a true disc problem will have a positive response to diskography. In this way the exact disc that is a problem is identified. A normal disc will not produce pain with diskography.
References
Spiros G. Pneumaticos, MD, PhD et al. Diskography in the Evaluation of Low Back Pain. In Journal of the American Academy of Orthopaedic Surgeons. January 2006. Vol. 14. No. 1. Pp. 46-55.