The Value Of Shear Wave Elastography In Diagnosis Of Type 2 Diabetic Peripheral Neuropathy

Objectives:To observe the value of shear wave elastography(SWE)in diagnosis of type 2 diabetic peripheral neuropathy.Methods:1.A total of 112 patients with type 2 diabetes diagnosed at the First Affiliated Hospital of Nanchang University from December 2016 to October 2017 were collected(According to the Diagnostic Criteria for type 2 diabetes regulated by the American Diabetes Association in 1999).All patients underwent ultrasound and neurophysiological examination.Patients with type 2 diabetes were divided into DPN group and NDPN group according to clinical symptoms and neurophysiological results.Among them,62 were in DPN group and 50 in NDPN group.At the same time,52 healthy volunteers whose age and body mass index matched to the physical examination in our hospital were selected as the control group.2.The Aixplore type SWE ultrasonic diagnostic apparatus of the French SuperSonicImagine was used,and the SL15-4 linear array probe was used with a frequency of 4-15 MHz.All patients were supine,and the lower extremities slightly extended to allow the patient to relax naturally.The conventional two-dimensional ultrasound examination was performed first.The sacral nerve was scanned horizontally from the internal malleolus.The transverse section of the sacral nerve was shown.The boundary of the sacral nerve was determined.The internal structure of the sacral nerve and the echo of the nerve bundle were observed.The sacral nerve transect was measured at 4 cm above the medial malleolus.Area(unit:mm~2).Rotate the probe 90°and scan along the long axis of the radial nerve.Select the area where the radial nerve moves horizontally.Fix the probe and start the SWE mode(preset the range of color Young's modulus to 0-200kPa)until the image stabilizes 3-5 After 2seconds freeze the image,enable the Q-BOX function(ROI diameter is 2mm)to measure the Young's modulus value of the tibial nerve,the above measurements are measured continuously for 3 times,and the average value is recorded and calculated.3.The cross-sectional area and Young's modulus values of the tibial nerves were compared between the three groups.The receiver operator characteristic(ROC)curve was drawn.The best cut-off point value and area under the curve were calculated and the diagnosis of both was evaluated.efficacy.P<0.05 was considered statistically significant.Results:1.There were 62 patients in the DPN group,34 males and 28 females,aged 38-74 years,mean age 57.7±10.7 years.47 patients had clinical manifestations of paresthesia or pain in both lower extremities,2 patients showed unilateral lower limb paresthesia,and 13 patients No obvious clinical symptoms;NDPN group 50 cases,24males and 26 females,aged 38-76 years,mean age 56.5±10.0 years old,18 cases of paresthesia in both lower extremities,4 cases showed unilateral lower limb paresthesia,28 patients had no obvious clinical symptoms;in the control group,there were 52 patients,26 males and 26 females,aged 40-75 years,mean age 56.9±10.5years,and no lower limb paresthesia.2.Comparing the course of DPN and NDPN,the DPN group(10.5±6.8 years)was longer course than NDPN group(7.6±5.5 years),but there was no significant difference between the two groups(p=0.083,p>0.05).3.The two-dimensional ultrasound of the normal radial nerve longitudinal section shows discontinuous linear hypoechoic and hyperechoic.The cross-section shows a"screen-like"structure,and the epineurium shows a thin high echo.In the DPN group,the sacral nerve was mainly characterized by the reduction of the nerve beam echo,the thickening of the epineurium,and the"screen-like"structure.4.There was no significant difference in the cross-sectional area of the left and right tibial nerves in the three groups(p>0.05).The cross-sectional area of bilateral phrenic nerve in DPN group was greater than that in NDPN group and control group(p<0.05).The cross-sectional area of bilateral phrenic nerve in NDPN group was higher than that in control group,but the difference was not statistically significant(p>0.05).There was no significant difference in the Young's modulus values between the left and right eyes of the three groups(p>0.05).Compared with the control group,the Young's modulus values of the bilateral phrenic nerves in the DPN group and the NDPN group were significantly higher(p<0.05).The Young's modulus of the tibial nerve in the DPN group was higher than that in the NDPN group,and the difference was statistically significant(p<0.05).5.The ROC curve was plotted to obtain a cut-point value for the diagnosis of DPN.Using the radial nerve cross-sectional area of 17.5 mm~2,the diagnostic sensitivity was 80%,the specificity was 72%,and the area under the curve was 0.804.Using the Young's modulus value of the phrenic nerve 50.1kPa as the cutoff value for the diagnosis of DPN,the sensitivity was 85.0%,the specificity was 88.0%,and the area under the curve was 0.936.Conclusion:1.The SWE technique is useful for assessing the stiffness of the sacral nerve and can be used to assess the stiffness of nerves after peripheral neuropathy in patients with type 2 diabetes,providing a reference for clinical diagnosis of DPN.2.The phrenic nerve Young's modulus value of 50.1kPa was taken as the cutoff value for the diagnosis of DPN.The sensitivity was 85%and the specificity was 88%.And compared with the two-dimensional assessment of radial nerve morphological changes,this method diagnoses DPN has a higher diagnostic efficiency.3.There was a statistically significant difference in the hardness of the radial nerve between the NDPN group and the control group,suggesting that the nerve stiffness of the diabetic patients had changed before the appearance of DPN.Therefore,SWE may provide valuable value for the early diagnosis of DPN by evaluating the change of radial nerve stiffness.