SERIAL GADOLINIUM-ENHANCED MR-IMAGING AFTER LUMBAR DISC RESECTION - OBSERVATION OF THE AFFECTED ROOT

A prospective study was undertaken to clarify the relationship between postoperative morphological/pathological changes in the affected root and the clinical developments after disc resection. Gadolinium-enhanc ed magnetic resonance (MR) imaging was performed at 1 week, 5 weeks, 3 months, and 6 months after surgery for 28 patients of 34 consecutive patients who underwent single-level disc resection. Enhancement/thicke ning of the affected root was found to be 100%/89% at 1 week, 50%/57% at 3 months, and 32%/37% at 6 months after surgery. Patients with root enhancement and thickening at 3 and 6 months after surgery had less c linical improvement than patients without it. There was consistent cor relation between postoperative clinical developments and nerve root en hancement/thickening in enhanced MR imaging. To use enhanced MR imagin g as an evaluation tool after disc surgery might increase the diagnost ic accuracy and reduce failed back surgery syndrome.