Multiband IVIM-DTI Combined With BOLD For Evaluating The Microphysiological Characteristics Of Early-period Transplanted Kidney

Purpose:To evaluate the water molecular diffusion characteristics and blood oxygen level of transplanted kidney combining multiband DTI-IVIM with BOLD,analyzing the functional changes of transplanted kidney and exploring the potential relationship between the changes of blood oxygen level and water molecular diffusion in transplanted kidney.Materials and Methods:90 early renal allograft recipients and 30 age-matched healthy volunteers were prospectively collected.They were examined by multiband DTI-IVIM and BOLD.After post-processing,the parameters were measured,including FA value,ADC value,ADC _fastast value,ADC _slowlow value,f value and R2^*value.Serum creatinine?SCr?was recorded on the day of MR examination in patients after renal transplantation,which helped divide the persons into:group 0?n=25?,healthy volunteers;group 1?n=45?,eGFR?60 ml/min/1.73 m²;group 2?n=25?,30?eGFR<60 ml/min/1.73 m²;group 3?n=25?,eGFR<30 ml/min/1.73 m².Observe and compare the characteristics of fMRI images of each group;the consistency of data measured by the two doctors was compared by intra-group correlation coefficient?ICC?;the differences of parameters between the cortical and medulla groups was compared by paired sample t-test;the differences of parameters between groups was compared by variance analysis;the correlation between the parameters and eGFR was analyzed with Pearson correlation analysis.;Logistic Regression Model and drawing ROC curve was used to compare the diagnostic efficacy of different parameters in differentiating different transplanted renal functions,and to determine the best differential diagnostic parameters and the best differential diagnostic threshold.P<0.05,the difference was significant.Results:?1?The consistencies of the data measured by two physicians was good,ICC was above 0.75;?2?There were no significant differences in ADC_slowlow values between cortex and medulla in group 1,ADC?ADC_slow?ADC_fast?f values in group 2,ADC_fast?f?R2^*values in group3?P>0.05?;ADC values,ADC_fastast values and f values in cortex in the other group were significantly higher than those in medulla,while FA values and R2*values in cortex were significantly lower than those in medulla?P<0.05?.?3?The FA value of cortex in group 0 was significantly higher than that in other groups;the FA value of medulla showed a decreasing trend in groups 1,2 and 3;The cortical ADC values of group 0 were significantly higher than those of group 2 and group 3?P<0.01?;the ADC_slowlow value of cortex in group 1 was higher than that in group 2?P<0.01?;the ADC_slowlow value of cortex in group 2 and 3 was significantly different?P<0.05?;the cortical ADCfast value of group 0 was significantly lower than that of group 1?P<0.01?,and that of group 1 was significantly higher than that of group 2?P<0.01?;there was no significant difference in cortical ADCfast value between groups 2 and 3?P>0.05?;the cortical f value of group 0 was less than that of group 1,group 2,and group 3 decreased?P<0.01?;the medullary f value of group 1was greater than that of group 0?P<0.01?;the medullary f value of group 2 was greater than that of group 0?P<0.05?.?4?The ADC value,ADC_slowlow value,f value and medullary ADC value,ADC_slowlow value and R2^*value of transplanted kidney cortex were moderately and positively correlated with eGFR,while the FA value and cortical ADC_slowlow value were positively correlated with eGFR intensity.There was no significant correlation between cortical R2^*value,cortical FA value,cortical ADC_fastast value,medullary ADC_fastast value and medullary f value and eGFR?P>0.05?.?5?Among the single index values,the area under ROC curve of FA value in medulla was the largest?0.716?.When medullary FA was combined with cortical ADC_slow,AUC was 0.777;when medullary FA,cortical ADC_slowlow and medullary R2^*were combined,AUC was 0.803.Conclusion:Multiband IVIM-DTI is an innovative technology,combining IVIM and DTI model with BOLD technology can comprehensively assess the water molecular diffusion characteristics and blood oxygen metabolism levels of normal kidneys and early transplanted kidneys in different functional states.