Application Of Diffusion Tensor Imaging In Lumbar Disc Herniation

Objective:Diffusion tensor imaging(DTI)have been used to investigate the differences of fractional anisotropy(FA)and apparent diffusion coefficient(ADC)values between compressed nerve roots in patients with lumbar disc herniation and normal nerve roots in healthy volunteers.Diffusion tensor imaging(DTI)also has been used to investigate the correlation between microstructural changes of compressed nerve roots,clinical symptoms(ODI)and their duration.Combined fiber tractography(FT)to observe the morphology and internal microstructure changes of nerve root,which provide a reliable basis for clinical evaluation of lumbar disc herniation and treatment in time effectively.Methods:Thirty-two healthy volunteers and thirty-two patients with lumbar disc herniation were enrolled in our study.Philips 3.0T TX MRI was used to examine routine MRI and DTI in all the subjects with L4 to S1 nerve roots.Select the intervertebral foramen area for the region of interest.By measuring the FA value and ADC value quantitatively in healthy control group and compressed nerve roots group and contralateral uncompressed nerve roots group,we can analyze whether there exists differences between them.we can analyze whether there exists differences in the mean FA value and ADC value of healthy volunteers in different segments of L4-S1 nerve roots and different age groups.and also we can analyze the association among ADC value,FA value and ODI and their duration.Results:1 There was no significant difference found in the mean FA value and ADC value of healthy volunteers in each segment of L4-S1 nerve roots(P>0.05).There was no significant difference found in the mean FA value and ADC value of healthy volunteers age>35 years group and age<35 years group(P>0.05).2 The mean FA value of the compressed nerve roots group was significantly lower than the FA value of the healthy volunteers nerve roots group and contralateral uncompressed nerve roots group(P<0.05),which exists statistical significance.The mean ADC value of the compressed nerve roots group was significantly lower than the ADC value of the healthy control nerve roots group and contralateral uncompressed nerve roots group(P<0.05),and it exists statistical significance.The mean FA value and ADC value of the contralateral uncompressed nerve roots group was no significant difference than the healthy control group nerve roots group(P>0.05).3 In the compressed nerve roots group,a significant negative association was observed among FA value,ODI and symptom duration.However,no significant association was observed among ADC value,ODI and symptom duration.4 Fiber tractography(FT)can clearly show the shape characteristics of L4-S1 nerve roots.Normal nerve roots are symmetrically,While compressed nerve roots are sparse,dislocated,thinning.Conclusion:1 The lumbar sacral nerve root DTI imaging can be used to quantify the nerve root changes of lumbar intervertebral disc herniation and quantify the extent and range of nerve damage.The DTI imaging can detect the anterior lumbar sacral root injury early and provide new examination methods for early diagnosis of early diagnosis.2 Get the FA value for healthy volunteers.At the same time,the patients with lumbar intervertebral disc were found to have no difference in the FA value of the uncompressed group and the healthy control group,and it can be used as normal control.3 The FA value is a quantitative indicator of nerve root damage,a significant negative association was observed among FA value,ODI and symptom duration.The more the severe the clinical symptom is,the smaller FA value will be.The longer the history is,the smaller FA value will be.The association can be used to evaluate the degree and time of nerve root injury of the patients with lumbar disc herniation,Which can provide references for early intervention and prognosis.4 The change of ADC value is currently in dispute,and whether it can be used as a reference for evaluating nerve root injury in lumbar disc herniation remains to be further explored.5 The FT can visually show the change of the pressure shape of the nerve root and determine the position of pressure,which is worth promoting the application.