The Diagnostic Value Study Of Functional Magnetic Resonance Imaging Applies To Spinal Nerve Roots Injury In Lumbar Disc Herniation

Objective: Diffusion tensor imaging(DTI) and fiber tractography(FT) have been used to investigate the differences of fractional anisotropy(FA) and apparent diffusion coefficient(ADC) values between healthy volunteers and patients with disc herniation, and to evaluate the differences of FA and ADC values in patients with varying degrees of spinal nerve roots pain.Methods: Total 20 patients with foramina disc herniation or posterolateral unilateral sciatica and 20 healthy volunteers were included in our study. Diffusion tensor imaging and fiber tractography were performed on all patients and volunteers by Philips Achieve 3.0T TX MRI scanner, and measured the average value of FA and ADC values in L4 or L5 nerve roots. P<0.01 indicated significant statistical significance, P<0.05 indicated exist statistical significance, P>0.05 indicated there was no statistical significance. All patients and healthy volunteers were scored by JOA and VAS score. FA and ADC values were analyzed with JOA and VAS score by Pearson test to investigate if there were correlation. The imaging parameters used for FT: Minimum FA = 0.15, Minimum length of fiber =10 mm, Angle selection=28°.Results: The stressed position of lumbosacral spinal nerve roots were clearly displayed in fiber tractography imaging. FA and ADC values of L4 and L5 nerve roots in all patients and volunteers were measured at the same time. There was no significant differences between the bilateral spinal nerve roots of the same level in healthy volunteers according to FA and ADC values(P>0.05). FA values of compressed spinal nerve roots in patients were significantly lower than the spinal nerve roots FA values of the control group(P<0.01), and ADC values higher than the spinal nerve roots of opposite side and the control group(P<0.01). There was also no significant differences between the normal spinal nerve roots in patients and the spinal nerve roots in the control group according to FA and ADC values(P>0.05).There was no significant correlation between FA and ADC values and JOA and VAS score in compressed spinal nerve roots.Conclusions: Diffusion tensor imaging and fiber tractography can clearly and completely display the lumbosacral spinal nerve roots. In patients who have lumbar disc herniation, DTI and DTT can directly observe the courser and the stressed position and shape of spinal nerve roots. This provides quantitative indicators of lumbosacral radiculopathy.