CT scanning of lumbar discography. A useful diagnostic adjunct.

Twenty-two patients with continued, undiagnosed symptoms of low back and sciatic pain for an average of 14 months were assessed. Patients studied had prior negative evaluations, including EMG, CT scanning, and/or metrizamide myelography. Three-level, posterolateral, extradural discography was performed on the side opposite the sciatica. One to 6-hours after discography, CT scanning was performed on all injected discs: 91% demonstrated abnormal discograms at one/more levels. CT imaging demonstrated contrast tracking to the periphery of the disc in 82%. Discography reproduced the patient's symptoms in 77%. The direction of contrast tracking seen on scanning correlated with clinical symptoms in 73% and with symptoms at discography in 82%. CT scanning was thought to be a useful adjunct to lumbar discography in patients with prior negative evaluations.