DTI Quantitative Analysis Was Performed To Evaluate The Feasibility Of Nerve Repair After Minimally Invasive Surgery For Lumbar Disc Herniation

Objective:To study the feasibility of nerve repair after Percutaneous transforaminal endoscopic discectomy for lumbar disc herniation by MR diffusion tensor imaging?DTI?.Methods:This study is prospective.Nineteen patients with lumbar intervertebral disc herniation confirmed were collected by clinical symptoms and MR imaging manifestations in spine surgery.DTI examination was performed on L5 and S1 nerves of these 19 patients before one day surgery,three days,thirty days and ninety days after surgery,hereinafter referred to as"L5-S1".ROI was performed by 2 experienced diagnostic physicians at the lateral,middle and far side of L5-S1 nerve compression and at the"seed point"near,middle and far side of the same segmental healthy.The average DTI parameters of ROI at three sites of each nerve were taken as the final DTI parameters of the corresponding nerve.The DTI parameters of the compressed side nerve roots of L5-S1 nerves and the healthy side nerve of the same segment were in normal distribution 1 day before the surgery and 90 days after the surgery,and the paired t test was used for comparative analysis.One-Way ANOVA was used to compare DTI parameters of L5-S1 nerves affected side nerves one day before surgery,three days,thirty days and ninety days after the surgery.Results:?1?The fractional anisotropy?FA?of L5-S1 nerves on the affected side was significantly lower than that of the healthy side day before surgery.The FA values of the affected side of L5 to S1 nerve were as followings:?L5 nerve?0.354±0.03 and?S1?0.359±0.02,and healthy side were?L5 nerve?0.446±0.01 and?S1 nerve?0.459±0.02?T value range from-10.188to 37.683,P<0.05?.The apparent diffusion coefficient(ADC value×10^-3 mm ²/s)of the affected side of L5-S1 nerves was significantly higher than that of the healthy side 1 day before surgery.The ADC values of L5-S1 nerves on the affected side were as followings:?L5 nerve?1.649±0.13 and?S1 nerve?1.634±0.05,and healthy side was?L5 nerve?1.392±0.12 and?S1nerve?1.441±0.08?T value range from 8.527 to 11.832,P<0.05?.Difference was statistically significant.?2?The nerves DTI parameters of L5-S1 nerves gradually increased the FA value and decreased the ADC value of the affected side at one day before the surgery,three days,thirty days and ninety days after the surgery.The FA values of the affected side of L5-S1 nerves were respectively as followings:?L5 nerve?0.354±0.03,0.379±0.03,0.41±0.04,0.421±0.02 and?S1 nerve?0.359±0.02,0.367±0.03,0.381±0.03,0.437±0.02?F value ranges from 9.282 to 20.248,P<0.05?.The ADC values of the affected side of L5-S1 nerves were respectively as followings:?L5nerve?1.649±0.13,1.546±0.08,1.474±0.13,1.409±0.07 and?S1 nerve?1.634±0.05,1.636±0.10,1.529±0.08,1.476±0.12?F value ranges from 8.668to 9.954,P<0.05?.DTI parameters on the affected and healthy sides of L5-S1nerve were not statistically significant ninety days after surgery.Conclusion:DTI can quantitatively evaluate the feasibility of postoperative repair of lumbosacral nerve...