Evaluation Of BOLD And DTI Quantitative Parameters In The Diagnosis Of Early Diabetic Kidney Disease

Objective To explore the value of BOLD and DTI quantitative parameters in the early diagnosis of DKD,based on the imaging study of Blood oxygenation level-dependent imaging(BOLD)and Diffusion tensor imaging(DTI)in Diabetic kidney disease(DKD)model rats.Materials and Methods Early experiments,the selection of 50 cases of healthy clean male SpragueDawley rats,10 cases were randomly divided into blank group,40 cases made module,building groups of rats with high sugar and high fat diet induced chain combined with intraperitoneal injection of small dose of urea with cephalosporins(STZ Streptozotocin)early DKD model rats,after building the blank group,model group rats line T2 WI,BOLD,DTI scans.Microalbumin(Um Alb)was measured 24 hours before MRI scan in the blank group and the model group.After MRI scan,the rats were immediately sacrificed,and venous blood was collected to detect biochemical indicators: serum creatinine(Scr),serum urea nitrogen(Bun),serum cystatin-C(CysC).According to the pathological results of kidney,early DKD model and normal rat kidney were included.According to the pathological stages of DKD,all the included normal rats' kidneys were set as a blank control group,and the early DKD model rats' kidneys were divided into DKD?-? group and DKD? group according to the pathological stages.After the completion of grouping,immunohistochemical semi-quantitative indicators of the blank control group,DKD?-? group and DKD? group were collected: microvascular density(MVD),TGF-?1,biochemical indicators:24h Um Alb,serum Scr,serum Bun,serum CysC,and quantitative parameters of BOLD and DTI in the kidney: renal cutaneous and medulla R2* value,ADC value and FA value.Statistical analysis was performed on the data:(1)to compare the difference of immunohistochemical indexes between the kidney of the blank control group and the kidney of the early DKD subgroup.(2)to compare the differences of the above biochemical indexes between the blank control group,the DKD ?-? group and the DKD ? group.(3)to compare the differences between BOLD and DTI quantitative parameters in the blank control group,DKD?-? group and DKD? group.(4)the ROC curve was used to evaluate the efficacy of the commonly used biochemical indicators,BOLD and DTI quantitative parameters on the early DKD and the combined diagnosis.Results1.Modeling and grouping After modeling,a total of 32 successful diabetic rat models were determined according to the success criteria of the diabetic model rats.After 4 weeks of observation,5 cases died.Finally,27 cases of rats with a total of 54 kidneys were sent to the model group for pathological examination.In the blank group,10 rats with a total of 20 kidneys were sent for pathological examination.Pathological results showed that all the 54 kidneys in the model group were early DKD kidneys,24 in the DKD?-? group and 30 in the DKD ? group according to the pathological staging standard.All the 20 kidneys in the blank group were normal kidneys,so the blank control group was determined to be 20 kidneys.2.Immunohistochemical index(1)The mean renal cortical microvascular density(MVD)between the blank control group,DKD ?-? group and DKD ? group were(96.20±8.24)/HP,(107.51±19.38)/HP and(124.51 ± 21.46)/HP,respectively,with statistically significant differences between the three groups(P < 0.05).(2)The renal TGF-1 values were(96.20±8.24)/HP,(107.51±19.38)/HP,and(116.51±12.14)/HP,respectively,in the blank control group,the DKD ?-? group and the DKD? group,and the difference between the two groups was statistically significant(P < 0.05).3.Biochemical indicators Blank control group,DKD?-? group,DKD? group 24 hours Um Alb between the three groups,serum Bun,serum CysC were statistically difference(P<0.05),after comparing the two,DKD ? group of 24 h Um Alb stronger than blank control group,serum Bun and DKD ?-? group(P<0.05),and blank control group,DKD ?-? group no statistical difference between groups(P>0.05).Serum CysC gradually increased in the blank control group,DKD?-? group and DKD ? group(P<0.05).There was no significant difference in serum Scr between the three groups(P>0.05).4.BOLD and DTI quantitative parameters.(1)BOLD-R2* value: the cortical R2* value of DKD ? group was higher than that of the blank control group and DKD?-? group(P<0.05),and the cortical FA value of the blank control group and DKD ? group was not statistically significant(P> 0.05).The value of medullary R2* in DKD?-? group and DKD ? group was higher than that in the blank control group,and the value of medullary R2* in DKD i-ii group was higher than that in DKD ? group(P< 0.05).(2)DTI-ADC value: there was no statistically significant difference in the cutaneous and medullary ADC value between the blank control group,the DKD ? group and the DKD ? group(P> 0.05).(3)DTI-FA value:there was no statistically significant difference in cortical FA value between the blank control group,The medullary FA values of The blank control group,DKD?-? group and DKD ? group(P> 0.05).And the differences were statistically significant(P < 0.05).5.Diagnostic efficacy(1)Biochemical indicators of the early diagnosis of DKD efficacy The sensitivity and specificity of urinary microalbumin to early diagnosis of DKD were 0.630 and 0.800 respectively.The sensitivity and specificity of serum urea nitrogen to early diagnosis of DKD were 0.556 and 0.750 respectively.The sensitivity and specificity of serum CysC to early diagnosis of DKD were 0.704 and 0.850 respectively.The diagnostic efficacy of serum CysC was the best among single laboratory indexes,and the AUC was 0.811.The diagnostic efficiency of combined biochemical indexes was higher than that of single biochemical chamber indexes,and the AUC was 0.833.(2)The diagnostic efficacy of BOLD and DTI quantitative parameters on early DKD The sensitivity of cortical R2* to the early diagnosis of DKD was 0.722 and the specificity was 0.700.The sensitivity of medulla R2* to early DKD diagnosis was0.741 and the specificity was 0.700.The sensitivity and specificity of medullary FA to the diagnosis of early diabetic nephropathy were 0.850 and 0.648 respectively.The diagnostic efficiency of medulla FA value was the best among the single f-MRI indexes,and the AUC was 0.838.The diagnostic efficiency of combined functional magnetic resonance index was higher than that of single functional magnetic resonance index,and the AUC was 0.909.(3)Comparison of diagnostic efficacy of biochemical indexes,BOLD and DTI quantitative parameters The efficacy of BOLD and DTI quantitative parameters in the early diagnosis of DKD was higher than the commonly used biochemical indexes.The diagnostic efficacy of BOLD and DTI quantitative parameters combined with commonly used biochemical indexes reached the maximum,and the AUC was 0.926.conclusion1.The R2* value of the renal dermal and medullary is feasible to evaluate the oxygenation level and hypoxia degree of the early DKD kidney;2.The FA value of the renal medulla is feasible to evaluate the anisotropic changes of the movement of water molecules in the renal medulla at the early stage of DKD.3.In combination with BOLD and DTI quantitative parameters,the diagnostic efficacy of early DKD was higher than that of common biochemical indexes.4.The combination of quantitative parameters and biochemical indexes of functional magnetic resonance can improve the sensitivity,specificity and accuracy of early diagnosis of DKD,and provide a new idea for early diagnosis of DKD.