We report a series of 98 patients with back pain and sciatica in whom the MRI scan was reported as normal. The patients were referred by their General Practitioners and the MRI was the first and only investigation. The patients were subsequently subjected to plain radiographs including weight-bearing spot laterals of the lumbo-sacral spine, and discography in which pain provocation and reversal were judged as indicative of a pain source. Significant degenerative change was noted in plain radiographs in 27 cases, and weight-bearing views revealed a spondylolisthesis in eight cases where the supine view and MR had appeared normal. Discography had revealed intradiscal fissuring correlating with pain reproduction and reversal in 36 cases.

MRI is a scarce resource with very long waiting lists in many parts of the country and the value of the investigation may have been exaggerated both in terms of false positive and false negative results. On the basis of our study we recommend a review of radiological policy.