The Value Of Virtual Touch Quantification Technique In The Diagnosis Of Diabetic Nephropathy

Part1 Correlation Analysis of Shear Wave Velocity of Renal Parenchyma and Color Doppler Flow Parameters in Diabetic NephropathyObjective To investigate the correlation between shear-wave velocity(SWV)of renal parenchyma on Virtual touch quantification(VTQ)and color Doppler flow imaging(CDFI)parameters of renal artery branches at all levels in patients with diabetic nephropathy(DN)and to make sure that if the renal blood flow changing effects the hardness of renal parenchyma.Methods From March 2017 to December 2017,42 patients with DN diagnosed according to Chinese type 2 diabetes prevention and treatment guidelines(version 2013)in our hospital were enrolled in this stuay.Another 33 healthy volunteers were selected as the control group.Each subject of both two groups underwent CDFI and VTQ examinations.The hemodynamic parameters,including the peak systolic velocity(PSV),end diastolic velocity(EDV)and resistance index(RI)of renal artery branches at all levels,and SWV of renal parenchymal were measured and compared between the two groups.Additionally,the relationship between SWV and each hemodynamic parameter was further analyzed.Results The mean RI of the main,segmental and interlobar renal artery in the DN group was(0.71±0.09),(0.66±0.08)and(0.62±0.07),respectively.For the control group,that was(0.61±0.05),(0.57±0.05)and(0.57±0.04),respectively.The mean RI of each renal artery branch in the DN group was significantly higher than that in the control group(P<0.05).In the DN group,the mean PSV of the main and segmental artery was(70.9±21.8)cm/s and(39.7±9.6)mm/s.In the control group,those were(77.3±18.8)cm/s and(43.3±9.4)cm/s.The mean PSV of the main and segmental artery in the DN group was lower than that of the control group,but no significant difference was found(P>0.05).The mean PSV of the interlobular artery in the DN group was significantly lower than that in the control group(26.1±9.0 cm/s vs.29.4±7.6 cm/s)(P<0.05).The mean EDV of the main,segmental and interlobar artery in the DN group was(21.0±7.5)cm/s,(13.0±4.3)cm/s and(9.4±2.9)cm/s,respectively.In the control group,that was(30.0±8.4)cm/s,(18.3±4.2)cm/s and(12.7±3.7)cm/s,respectively.The mean EDV at all levels of the renal artery in the DN group was significantly lower than that in the control group(P<0.05).Correlation analysis showed that there was a negative correlation between SWV and each mean RI of main,segmental and interlobar artery(r=-0.43,P<0.05;r=-0.41,P<0.05;r=-0.29,P<0.05).In addition,except the mean PSV of the main renal artery(r=0.10,P=0.24),SWV was positively correlated with PSV of the segmental artery and interlobar artery(r=0.17?P<0.05;r=0.17?P<0.05);There was a positive correlation between SWV and the mean EDV of main,segmental and interlobar artery(r=0.30,P<0.05;r=0.44,P<0.05;r=0.33,P<0.05).Renal cortex SWV in DN patients was significantly lower than that in the control group((2.78±0.63)m/s vs.(3.54±0.52)m/s,P<0.05).The AUC of SWV for distinguishing the control and DN group was 0.82(95%CI,0.75-0.88;P<0.001).A SWV cutoff value of 3.34 m/s produced the best performance,the sensitivity,specificity,positive predictive value(PPV)and negative predictive value(NPV)was 85.7%,66.7%,76.6%and 78.6%,respectively.Conclusion The SWV value of renal parenchyma in patients with DN is related to thehemodynamic changing of renal.The VTQ technique has potential value to assess renal parenchyma impairment of DN patients.Part 2 The value of Virtual touch quantification Technique in the diagnosis of Diabetic NephropathyObjective To investigate the value of Virtual touch quantification(VTQ)technique in diabetic nephropathy(DN)staging.Methods Forty-two patients with DN diagnosed in our hospital from March 2017 to December 2017 were enrolled in this study.According to urinary albumin and creatinine ratio(ACR),DN patients were divided into two groups:early stage group(DN1 group)(ACR ? 30 mg/mmol,DN stage ? ?,n = 24)and clinical stage group(DN2 group)(ACR>30 mg/mmol,DN stage? IV,n = 18).Another 33 healthy volunteers were selected as control group at the same period.All subjects underwent VTQ examination and the shear wave velocity(SWV)of the renal parenchyma was measured and compared among different groups.Results The mean SWV of the control group,DNl group and DN2 group was(3.54±0.52)m/s,(2.98±0.60)m/s and(2.51±0.58)m/s,respectively.Significant differences of the mean SWV were found among the three groups(P<0.05).The area under the ROC curve(AUC)of SWV for distinguishing the control group and the DN1 group was 0.76(95%CI,0.67-0.83;P<0.001).Using a SWV cut-off value of 3.51 m/s,the sensitivity,specificity,positive predictive value(PPV)and negative predictive value(NPV)was 85.4%,59.1%,60.3%and 84.8%,respectively.The AUC of SWV for distinguishing the control group and the DN2 group was 0.85(95%CI:0.76-0.91;P<0.001).Using a SWV cut-off value of 3.41 m/s,the sensitivity,specificity,PPV,NPV was 94.4%,63.6%,58.6%and 95.5%,respectively.The AUC of SWV for distinguishing DN1 and DN2 patients was 0.69(95%CI,0.58-0.79;P<0.001).Using a SWV cut-off value of 3.09m/s,the sensitivity,specificity,PPV,NPV was 83.3%,47.9%,54.5%and 79.3%,respectively.Conclusion The SWV of renal parenchyma gradually decreased with the increase of renal damage degree.VTQ has potential value in assessing the DN staging.