Preliminary Study Of Multiparametric MRI In Early Kidney Injury In Type 2 Diabetes

Objective:The feasibility and clinical application of magnetic resonance diffusion kurtosis imaging(DKI)and blood oxygen level-dependent(BOLD)imaging for the evaluation of kidney damage in patients with simple diabetes mellitus(SDM),early diabetic kidney disease(EDKD)and healthy volunteers were investigated.The study investigated the feasibility and clinical application of the imaging technique for the evaluation of early kidney injury in type 2 diabetes mellitus(SDM),early diabetic kidney disease(EDKD)patients and healthy volunteers.Materials and methods:Fifty-four patients with type 2 diabetes mellitus(T2DM)who were outpatients and inpatients in the Department of Endocrinology of the Affiliated Hospital of North sichuan Medical College from July 2018 to September 2020 were collected and divided into SDM group(n=30)and EDKD group(n=24)according to the presence or absence of microalbuminuria.Meanwhile,30 healthy volunteers matched for gender and age(control group)were recruited to participate in this study.Fresh morning urine samples were collected from all participants within one week prior to MRI scanning,and the urinary albumin creatinine ratio(UACR),estimated glomerular filtration rate(eGFR)and glycated glycosylated protein ratio(GFR)were recorded,All subjects underwent fundus examination one by one.All subjects fasted for at least 4 hours before undergoing 3.0T MRI renal T2WI,BOLD and DKI scans.Two experienced radiologists placed regions of interest(ROI)in the cortical and medullary regions of the resulting renal pseudocolorograms and recorded the apparent spin-spin relaxation rate(R2*),mean kurtosis(MK),and kurtosis in the cortex of both kidneys.Mean kurtosis(MK)values and mean diffusivity(MD)values.The intra-group correlation coefficient(ICC)-was used to assess the agreement-between the two observations;the values of each parameter in the cortical medulla were compared among the three groups,and the corresponding ROC curves were plotted to analyze the diagnostic efficacy of each parameter value,and the measured values of each parameter were correlated with eGFR to investigate the clinical relevance of each imaging parameter among the three groups.Results:1.The MK,MD and R2*values of the renal cortex and medulla of the three groups of subjects measured by the two radiologists were in high agreement,with ICC>0.8;the differences in the values of each parameter between the right and left kidneys of the three groups of subjects were not statistically significant.2.With the progression of the disease,the MD value of renal cortex and medulla gradually decreased,and the MK value gradually increased,and the MD value of renal cortex and medulla and the MK value of cortex were statistically significant among the three groups.Further comparison between the adjacent two groups,the MK value of cortex in EDKD group was higher than that in SDM group(P<0.05),and that in SDM group was higher than that in control group(P<0.001),but the MK value in medulla was not observed;The MD value of control group was higher than that of EDKD group and SDM group(P<0.05),but there was no significant difference between EDKD group and SDM group.3.The R2*value of medulla in SDM group was higher than that in control group and EDKD group(P<0.001).4.R2*value of cortex and medulla and MK value of cortex were more accurate in the differential diagnosis between SDM group and EDKD group(R2*value of medulla:AUC=0.783;R2*value of cortex:AUC=0.669;MK value of cortex:AUC=0.718);Cortical MK values in the EDKD group showed a significant negative correlation with eGFR(r=-0.734,P<0.001),Medullary MD values in the EDKD group showed a weak positive correlation with eGFR(r=0.437,P=0.033),Medullary R2*value in SDM group showed a weak negative correlation with eGFR(r=-0.451,P=0.012),and there was no significant correlation between the other parameters.Conclusions:(1)BOLD and DKI are feasible in the screening of patients with early diabetic kidney disease.(2)The R2*value of medulla can observe the changes of renal oxygenation as early as in the period of simple diabetes,while the MK value of cortex and medulla can detect the renal damage in patients with early diabetic kidney disease,which indicates that DKI combined with bold examination has a certain value in the noninvasive detection of EDKD,which is expected to be used in the clinical diagnosis of early renal damage and disease monitoring in diabetic patients.