Background: In the diagnosis and treatment of adult degenerative scoliosis (ADS), the localization of symptomatic nerve roots is mainly based on the symptoms and signs of patients. Because of spinal rotation deformity, conventional MRI cannot accurately select the level of intervertebral disc for scanning. In the present study, MR diffusion tensor imaging (DTI) was used to diagnose symptomatic nerve roots in patients with ADS, and its effectiveness was evaluated by comparing with diagnosis based on symptoms and signs of nerve root block.
Methods: Thirty-six patients who were clinically diagnosed to have ADS underwent routine MRI and DTI examinations, and fractional anisotropy (FA) of each nerve root in the lumbar spine was quantitatively measured. The t-test was used to compare the FA values of nerve roots with and without neurological symptoms. Preoperative and postoperative clinical evaluations were conducted on the patients, and the t-test was used to evaluate the clinical effects of surgery.
Results: The FA values of symptomatic and asymptomatic nerve roots were significantly different (P<0.01). The DTI findings of symptomatic nerve roots were consistent with the diagnosis based on symptoms and nerve root block. The Japanese Orthopaedic Association (JOA), Oswestry Disability Index (ODI), Visual Analog Scale-Back Pain (VAS-BP), and Visual Analog Scale-Leg Pain (VAS-LP) scores of the postoperative patients were significantly improved as compared to those in the preoperation stage; the Cobb, Lumbar Lordosis (LL), Pelvic Tilt (PT), and Sacral Slope (SS) angles were corrected significantly post operation.
Conclusion: The FA value can be used as a marker for predicting symptomatic nerve root and is consistent with clinical symptoms. According to the results of DTI, precise nerve root decompression can relieve the symptoms. Therefore, DTI can be used as an effective auxiliary method for symptomatic nerve root localization in patients with degenerative scoliosis.