MR of enhancing nerve roots in the unoperated lumbosacral spine.

PURPOSE To evaluate prospectively the unoperated lumbosacral spine by gadolinium-enhanced MR for evidence of clinically correlative abnormal enhancement of nerve roots. METHODS Two hundred patients were prospectively studied with intravenous gadolinium- (0.1 mmol/kg) enhanced MR. Evidence was sought of intrathecal enhancement of lumbosacral nerve root(s), and the correlation of this enhancement with the clinical syndrome was evaluated. RESULTS Ten patients demonstrated abnormally enhancing lumbosacral nerve root(s) (5%). Of these, seven (70%) were associated with focally protruding disk pathology. The three (30%) remaining patients had isolated enhancement of multiple nerve roots in the absence of significant associated anatomic pathology. Overall, the correlation of radicular enhancement with the presenting clinical syndrome was excellent. CONCLUSION A breakdown in the blood-nerve barrier as observed on gadolinium-enhanced MR serves as a marker for nerve root pathology in the unoperated lumbosacral spine, which may have clinical relevance in certain clinical situations.