Application Of Diffusion Tensor Imaging In Diabetic Peripheral Neuropathy

Objectives: The purposes of this study were to analyze the correlation between diffusion tensor imaging(DTI)and electrophysiological parameters in diabetic peripheral neuropathy(DPN).To explored the diagnostic accuracy of DTI for DPN and whether the DTI parameters can be used as biomarkers to evaluate demyelinating and axonal injury.Methods: 32 patients with type 2 diabetes mellitus with peripheral neuropathy and 23 healthy controls matched for age and sex were enrolled.All of the clinical examination,biochemical examination and lower limb electrophysiological examination from the two groups of subjects were collected.The Siemens vireo 3.0 T magnetic resonance was used to collect T1 w and DTI images of the lower limb axial positions.After the image post-processing,the tibial nerve(TN)and common peroneal nerve(CPN)DTI parameters were obtained.Two sample T-test was used to compare the differences between the DPN and the HC groups,and the correlation between DTI parameters and electrophysiological parameters in the DPN group was assessed using Pearson or Spearman coefficients.Results:(1)There was no significant difference in age and gender between the two groups of subjects.Compared with the HC group,the glycated hemoglobin in the DPN group was significantly increased(p<0.0001),and the motor nerve conduction velocity(MCV)and compound muscle action potential(CMAP)amplitude of the tibial and common peroneal nerves were significantly reduced(p<0.05).The difference was statistically significant.(2)Compared with the healthy controls group,the fractional anisotropy(FA)of the tibial nerve and the common peroneal nerve in the DPN group were significantly reduced(p<0.0001),and the mean diffusivity(MD)and radial diffusivity(RD)were significantly increased(p<0.05).The axial diffusivity(AD)decreased slightly(p=0.168).(3)In the DPN group,the tibial nerve FA was significantly positively correlated with MCV(r = 0.66,p<0.0001),and MD and RD were significantly negatively correlated with MCV(r =-0.45,p<0.01;r =-0.56,P<0.001),there was no correlation between AD and MCV;the total peroneal nerve FA was significantly positively correlated with MCV(r =0.66,p<0.0001),and MD and RD were significantly negatively correlated with MCV(r =-0.35,p<0.05;r =-0.51,p<0.003),there was no correlation between AD and MCV;there was no correlation between all DTI parameters of the two nerves and CMAP.(4)FA,MD and RD of the tibial and common peroneal nerves have diagnostic efficacy on DPN,and FA has the highest diagnostic accuracy(The cutoff point for diagnosing DPN in the TN is 0.48,with a sensitivity of 78% and a specificity of 86%;the cutoff point for diagnosing DPN in the CPN is 0.44,with a sensitivity of 81% and a specificity of 91%).Conclusions: FA has a high diagnostic accuracy for the diagnosis of DPN,and RD can be used as a parameter for evaluating myelin sheath in DPN.DTI is expected to become an effective tool to assist treatment monitoring or predict treatment outcomes in patients with DPN.