A quantitative and clinical evaluation of nerve roots in lumbosacral radiculopathy using diffusion tensor imaging.

PURPOSE: This study aimed to investigate the relationship between the fractional anisotropy (FA) values of compressed nerves derived in diffusion tensor imaging (DTI) and the corresponding clinical symptoms for quantitative and clinical evaluation in patients with lumbosacral radiculopathy. METHODS: Thirty-six patients and ten volunteers participated in the study and measured with DTI. The resultant FA values for L5-S1 lumbar nerve roots were calculated at three sub-regions. Additionally, the DTI relevant tractography was also performed on L4-S1 nerve roots. Clinical symptoms were performed by Japanese Orthopedic Association (JOA) scoring for each patient and volunteer. RESULTS: The FA values of the nerves at the symptomatic side were significantly lower than those at the asymptomatic side (p < 0.001). Diffusion tensor tractography distinctly showed abnormalities in the symptomatic nerve tracts. There was a significant correlation between JOA scores and the FA values of the compressed nerves at middle and distal sub-regions (p < 0.005). CONCLUSION: The clinical symptoms associated robustly with the DTI derived FA values of the compressed nerves in patients with lumbosacral radiculopathy. Therefore, the FA values can be a potential clinical tool to evaluate the nerve roots in lumbosacral radiculopathy quantitatively.