The Application Value Study Of Diffusion Tensor Imaging On Cervical Spondylotic Radiculopathy

Object:The purpose of this study is to investigate multiple diffusion metrics changes in the diffusion tensor imaging（DTI）of cervical nerve roots and their relationship with the clinical severity of patients with cervical spondylotic radiculopathy.Method:High directional DTI and routine MR of the cervical nerve roots and were performed in 30 patients diagnosed of cervical spondylotic radiculopathy clinically and 24 healthy volunteers with a 3.0-T magnetic resonance system. The fractional anisotropy（FA） 、 apparent diffusion coefficient（ADC）were calculated from the DTI data and compared between the affected and unaffected sides in the same patient and between healthy volunteers and cervical spondylotic radiculopathy patients.By setting multi ROI area,the cervical nerve roots were delineated by fiber tractography（FT）. The correlation between the affected lateral nerve root’s DTI metrics and the clinical International Standards for Neurological Classification of Spinal Cord Injury（ISNCSCI） scores was analyzed.Result:1 C5-C8 cervical nerve roots could be clearly delineated by FT.FT showed C5-C8 nerve roots originated in intervertebral foramen,symmetrically coursed obliquely downward;2 In the healthy volunteers, no significant difference was found in the FA、ADC values between the left and right nerve roots at the same cervical level（FA:P =0.53–0.76;ADC:P=0.42–0.88） or across the root levels from C5 to C8 in the same subjects（FA:P= 0.23–0.79;ADC:P=0.40–0.97）; no significant difference was found in the FA（P=0.22）、ADC values（P=0.31） of nerve roots between the group of age>40 years and the group of age<40 years;3 In cervical spondylotic radiculopathy patients,the affected nerve roots FA=0.40±0.04、ADC=1.30±0.13×10^-3 mm²/s,while the unaffected nerve roots FA=0.45±0.04、ADC=1.18±0.13×10^-3 mm²/s.The FA values of the affected nerve root were lower than those of the contralateral nerve root（P<0.01） and the healthy volunteers nerve roots（P < 0.01）, while the ADC values were higher than the contralateral nerve roots（P <0.01） and the healthy volunteers nerve roots（P<0.01）;4、In symptomatic patients, there was on correlation between the clinical ISNCSCI scores and affected lateral nerve root’s DTI metrics（ISNCSCI –FA:r=0.095,P=0.613;ISNCSCI –ADC:r=1.141,P=0.451）.Conclusion:DTI and FT can directly observe the courser and the stressed position of cervical nerve roots.The variation of FA and ADC values in cervical spondylotic radiculopathy patients’ nerve roots, Can quantitatively reflect the pathological physiological change of affected lateral nerve roots.We suggest DTI and FT can potentially be used as further beneficial supplement to examination when clinical symptoms is not consistent with the result of conventional image examination.