[en] A total of 34 DTPA-enhanced magnetic resonance imaging (MRI) studies were made pre- and/or post-operatively by using chemical shift selective method in 31 patients with lumbar disc herniation. DTPA enhancement was seen in affected nerve roots in 7 of 15 preoperative cases and 6 of 12 postoperative cases with unfavorable course. When straight leg raising test revealed severe stimulation to the lower extremity nerve roots (less than 45degree), affected nerve roots were significantly enhanced with DTPA. All enhanced sites, except for one of arachnoid inflammation, was most remarkably compressed by herniation. Edema within the affected nerve root would be detected by DTPA-enhanced MRI. (N.K.)