Evaluation Of Renal Function With IVIM In Primary Glomerular Diseases

Objective:The changes of renal diffusion and perfusion in primary glomerular diseases(PGD)were evaluated by intravoxel incoherent motion(IVIM)imaging,and the correlation between the quantitative parameters of IVIM and estimated glomerular filtration rate(e GFR)was investigated,as well as the differential diagnosis efficiency of IVIM for mild,moderate and severe renal impairment in primary glomerular diseases.Methods:A total of 54 patients with primary glomerular disease diagnosed in the department of nephrology,Jincheng General Hospital were enrolled in this study.They were divided into experimental groups and divided into G_A,G_Band G_Csubgroups.In the G_Agroup(with mild renal impairment),e GFR was greater than 60 m L/(min·1.73m~2).In G_Bgroup(moderate renal impairment),e GFR was 30-59 m L/(min·1.73m~2);e GFR in G_Cgroup(severe renal impairment)was less than 30 m L/(min·1.73m~2).A total of 24 healthy persons were invited as the control group.IVIM and conventional MR scans were performed on all subjects in this study,and IVIM parameters(f,D,D*values)of the left and right renal cortical and medulla of all subjects were measured.The differences of renal IVIM parameters measured by two physicians were compared.The IVIM parameters of both kidneys and the IVIM parameters of renal cortex and medulla were compared.The differences of cortical and medulla IVIM parameters between control group and experimental group(G_A,G_Band G_Cgroups)were compared.Correlation analysis was used to explore the correlation between e GFR and renal cortical and medulla IVIM parameters.ROC curve was used to analyze the identification efficiency of IVIM parameters in renal cortex and medulla for different degrees of renal impairment.Results:1.There was no significant difference in f,D,D*values of renal cortex and f,D,D*values of renal medulla between the two physicians(all P>0.05).2.The f,D and D*values of left renal cortex and medulla in G_A,G_B,G_Cand control groups were not significantly different from the f,D and D*values of right renal cortex and medulla(all P>0.05).3.The f,D and D*values of renal cortex in experimental group and control group were higher than those in medulla,and the differences were statistically significant(P<0.05).4.Compared with the control group,f values of renal cortex and medulla in G_Agroup were lower than that in the control group(all P<0.05),but D and D*values of renal cortex and medulla were not statistically significant(all P>0.05).The f,D and D*values of renal parenchyma in G_A,G_Band G_Cgroups were significantly different(all P<0.05).The mean values of f,D and D*in cortex and medulla of the three groups were as follows:G_Agroup>G_Bgroup>G_Cgroup.5.The values of f,D,D*in renal cortex and f,D,D*in medulla were positively correlated with e GFR(r=0.614,P<0.001;r=0.743,P<0.001;r=0.469,P<0.001;r=0.462,P<0.001;r=0.706,P<0.001;r=0.302,P=0.026).6.The area under the ROC curve(AUC)values of f,D,D*of renal cortex and f,D,D*of medulla used to distinguish between mild and moderate,moderate and severe renal impairment were all greater than 0.69.The f value of renal cortex could distinguish the patients with mild renal impairment from the normal control group,and the AUC was0.696.The AUC of the combination of cortical f,D,and D*values and the combination of medulla f,D,and D*values to distinguish mild and moderate severe renal impairment in PGD patients were all greater than 0.95.Conclusion:IVIM can noninvasively assess renal diffusion and perfusion in patients with PGD,and to some extent,assess renal function in patients.The f value of renal cortex is a sensitive parameter to detect early renal function changes.With the deterioration of PGD patients,the f,D and D*values of renal medulla cortex and also decreased.The f,D,and D*values of renal cortex and medulla are correlated with e GFR,and the f,D,and D*values of IVIM have a high ability to identify different degrees of renal impairment of PGD.Therefore,IVIM provided us with another idea and imaging markers in the non-invasive quantitative evaluation of the degree of kidney damage in PGD.