Evaluation Of The Feasibility Of DTI In Lumbosacral Neuropathy And Its Correlation Analysis With Neuroelectrophysiology

Objective:To study the feasibility of diffusion tensor imaging(DTI)in assessment of lumbosacral neuropathy and to explore its relationship with neuroelectrophysiology.Methods:Collecting 18 lumbosacral neuropathy patients(experimental group)and 20 volunteers(control group),The experimental group were divided into experimental subgroup A(demyelination group,6 cases),subgroup B(Axonal injury with demyelination group,12 cases)based on electrophysiology.All of L4-SN nerves of the experiment group and the control group received DTI examination."Sowing points" as ROIs in the proximal,middle and distal of bilateral L4-SN nerves.The average of the 3ROIs DTI parameters of each nerve were taken as its final DTI parameters.Independent sample t test was used to evaluate the difference of the L4-SN DTI parameters between the experimental group and the control group.The ROC analysis of the receiver operating characteristic curve was performed on the FA values and λ⊥values ??of the control and experimental groups.The nonparametric rank correlation analysis was performed between the subgroup A and subgroup B FA values of the experimental group and the CMAP and mNCV of the tibial and common peroneal nerve.The differences DTI parameters among the control group,the experimental subgroup A and the experimental subgroup B were compared by the nonparametric independent samples Kruskal-Wallis H test and the Nemenyi test.Results:1 The independent sample t test showed there was no statistically significant difference in FA value,ADC value,λ∥value and λ⊥value between the same segmental nerve of the bilateral L4-SN in the control group(P>0.05)(Table 1).2 The independent sample t test showed there was no statistically significant difference in FA value,ADC value,λ∥value and λ⊥value between the same segmental nerve of the bilateral L4-SN in the experimental group(P>0.05)(Table 2).3 The independent sample t test showed the L4-SN FA values in the experimental group was significantly lower than those in the control group(P<0.05).The L4 and S1-SN ADC values ??of the experimental group were significantly higher than those of the control group(P<0.05).There were no significant statistical difference between λ∥values of L4-SN of the experimental and control groups(P>0.05).The L4-SN λ⊥values in the experimental group were significantly higher than those in the control group(P<0.05)(Table 3).4 The analysis of ROC of the experimental group and control group showed the AUC values of L4-SN FA values were 0.834,0.745,0.860,0.772 and 0.811 respectively,the cutoff values ??were 0.427,0.421,0.418,0.414 and 0.438 respectively,the sensitivity were 66.7%,72.2%,77.8%,83.3% and66.7% respectively,the specificity were 91.7%,69.4%,80.6%,61.1% and88.9% respectively.The AUC values of L4-SN λ⊥values were0.796,0.656,0.791,0.701 and 0.843 respectively,and the cutoff values??were 1208.31,1248.43,1304.96,1098.82 and 1072.15 respectively,the sensitivity were 55.6%,50.0%,66.7%,97.2% and 88.9% respectively,the specificity were 91.7%,77.8%,86.1%,36.1% and 66.7% respectively.So FA values and λ⊥values had the moderate ability to identify the experimental groups and control groups from the results of above.5 In the experimental subgroup A,there was no significant correlation between L4-S2 FA values and the CMAP in the tibial and common peroneal nerves of the lower limbs,and mNCV in the tibial and common peroneal nerves of the lower limbs(|rs|<0.6,P>0.01),There was a significant correlation between the SN FA value and the mNCV of the common peroneal nerve(rs=0.846,P<0.01),but no significant correlation between SN FA value between the CMAP(rs=0.301,P=0.341)and mNCV(rs=0.078,P=0.81)in the tibial and common peroneal nerves of the lower limbs.There were no significant correlation between L4-SN FA values and the CMAP and mNCV in the tibial and common peroneal nerves of the lower limbs in experimental subgroup B(|rs|<0.4,P=0.01).6 The Kruskal-Wallis H test of control group,experimental subgroup A and experimental subgroup B showed L4-SN FA values,λ⊥values and L4,S1-SN ADC values were significant different among control group,experimental subgroup A and experimental subgroup B(P<0.05),L5 ADC values were not significant among the three groups(P>0.05).Nemenyi test showed there were significant differences in FA values and λ⊥values between control group and experimental subgroup B(P<0.05),and there were differences in FA vaiues between control group and experimental subgroup A of L5(P=0.041)and between experimental subgroup A and experimental subgroup B of S1(P=0.047),but no significant differences in FA values and λ⊥values in other two paires of the rest nerves(P>0.05).Conclusion:DTI can evaluate lumbosacral neuropathy and it can identify patients with axonal injury with demyelination and healthy subjects,so it’s promising to achieve quantitative and qualitative diagnosis of lumbar neuropathy noninvasively,but the linear correlation between DTI and neuroelectrophysiology of lumbosacral neuropathy can not be found in the study.