| Objects:Diffusion tensor imaging(DTI)and intravoxel incoherent motion(IVIM)were used to explore the application value of magnetic resonance diffusion imaging biomarkers(MD,FA,D,D*and f)for early kidney function injury in type 2 diabetes.Methods:Forty-one inpatients with confirmed type 2 diabetes in our endocrinology department from October 2019 to September 2020 were recruited.Diabetic patients were classified according to albumin to creatinine ratio(ACR):normoalbuminuria group(NAU group=27,ACR<30mg/g)and microalbuminuria group(MAU=14,30mg/g<ACR<300mg/g).28 normal adult volunteers were recruited as control group during the same period.All participants were examined using DTI and IVIM with 3.0T MRI.After post-processed to diffusion imagings,DTI parameters(mean diffusivity[MD],fractional anisotropy[FA]),and IVIM parameters(true diffusion coefficient[D],pseudo-diffusion coefficient[D*],and pseudo-diffusion component fraction[f])were measured in the renal parenchyma(cortex and medulla)by two experienced abdominal radiologists independently.Diffusion parameters were compared among the groups using separate one-way analyses of variance.The above MR diffusion parameters were correlated among ACR,eGFR,and HbA1c.Diagnostic performances of various diffusion parameters for predicting diabetic renal damage were compared.Results:Cortical FA and D values in MAU group were significantly lower than those in control group(MAU group:FA value 0.253±0.176,D value 1.488±0.146×10-3mm2/s;control group:FA value 0.271±0.023,D value 1.641±0.135×10-3mm2/s;FA value p=0.018;D value p=0.03).Medullary FA and D values were significantly different among the three groups(p<0.001,p<0.001).The medullary FA and D values in MAU group(0.329±0.441,1.268±0.160×10-3mm2/s)were lower than those in NAU group(0.371±0.294,1.406±0.096×10-3mm2/s)and than those in control group(0.399±0.020,1.660±0.210×10-3mm2/s).Medulla D*in MAU group(13.512±3.696×10-3mm2/s)was lower than those in NAU group(19.270±7.423×103mm2/s).p=0.006)and control group(18.166±4.402×10-3mm2/s;p=0.003).The renal medulla D value(r=-0.441,P<0.001)and FA value(r=-0.262,P<0.05)were slightly negatively correlated with HbAlc among the three groups.A mild negative correlation was observed among D values of renal cortex and medulla(cortex:r=-0.263,p<0.05;medulla:r=-0.332,p<0.05),FA values of renal cortex and medulla(cortex:r=-0.273,p<0.05;medulla:r=-0.563,p<0.001),medulla D*value(r=-0.291,p=0.015)with ACR.The AUC of medullary FA,D values in differentiating control and NAU group were 0.769,0.878.The AUC of medullary FA,D,D*values in differentiating control and MAU group were 0.909,0.952,0.793.The FA+D of medulla was used to differentiate the control from NAU group and the control from MAU group,respectively;AUC was 0.935 and 0.985.The AUC of medullary FA+D+D*value was 0.913 in distinguishing NAU and MAU group.Conculsion:The D value of IVIM and the FA value of DTI were better than other diffusion parameters in the assessment of early renal injury in type 2 diabetes.Medulla FA+D had the highest AUC value in differentiating the MAU group from the control group. |
