The Research Of Combined BOLD-fMRI With IVIM Model In The Evaluation Of Chronic Kidney Disease

Objective Through the application of blood oxygen level dependent functional magnetic resonance imaging(BOLD-f MRI) technology and multi-b values of diffusion weighted imaging(DWI) intravoxel incoherent motion(IVIM) model quantitative measure the kidney cortical and medullary R2* values, slow ADC values and PF values, discuss the application value of its evaluation of renal function in patients with chronic kidney disease(CKD).Methods 33 patients with CKD(including 21 with moderate CKD and 12 with severe CKD) as well as 26 healthy volunteers(normal control group) were included. All of them received routine MRI scanning, BOLD-f MRI examination and multi-b values of DWI scans. The cortical and medullary R2* values, slow ADC values and PF values of bilateral kidneys in the control group and case groups were measured. Using SPSS13.0 statistical software, compare the differences of R2* values, slow ADC values and PF values between cortex and medulla in the normal control group and the case groups, using t test; compare the differences of cortical and medullary R2* values, slow ADC values and PF values between the three groups, using the One-Way ANOVA, compare between the two groups by LSD method. P-values <0.05 were considered statistically significant.Results 1. Comparison of R2* values, slow ADC values and PF values between cortex and medulla in CKD group and normal control group The renal cortical R2* values were significantly lower than those of medulla in the moderate and severe CKD group and normal control group, the difference was statistically significant(P<0.05). Three groups of renal cortical slow ADC values were significantly higher than those of medulla, the difference was statistically significant(P<0.05). Comparison of PF values between renal cortex and medulla in the control group, there was no statistically significant difference(P>0.05); The moderate and severe CKD group of renal cortical PF values were higher than those of medulla, the difference was statistically significant(P<0.05).2. Comparison of renal cortical and medullary R2* values between each group Comparison of renal cortical R2* values between the three groups, there was no statistically significant difference(P>0.05); There were significant differences between the three groups in renal medullary R2* values(P=0.000): Comparison of renal medullary R2* values between control group and moderate CKD group, there was no statistically significant difference(P>0.05); Renal medullary R2* values in the control group were significantly higher than those in severe CKD group, the difference was statistically significant(P=0.002). Renal medullary R2* values in the moderate CKD group is significantly higher than those in severe CKD group, the difference was statistically significant(P=0.000).3. Comparison of renal cortical and medullary slow ADC values between each group Comparison of renal cortical and medullary slow ADC values between the three groups, the differences was statistically significant(P=0.000): Renal cortical and medullary slow ADC values in the control group were significantly higher than those in moderate CKD group, the difference was statistically significant(P=0.000); Renal cortical and medullary slow ADC values in the control group were significantly higher than those in severe CKD group, the difference was statistically significant(P=0.000); Comparison of renal cortical and medullary slow ADC values between moderate and severe CKD group, there was no statistically significant difference(P>0.05).4. Comparison of renal cortical and medullary PF values between each group Comparison of renal cortical PF values between the three groups, there was no statistically significant difference(P>0.05); There were significant differences between the three groups in renal medullary PF values(P<0.05): Comparison of renal medullary PF values between control group and moderate CKD group, there was no statistically significant difference(P>0.05); Renal medullary PF values in the control group were higher than those in severe CKD group, the difference was statistically significant(P<0.05). Comparison of renal medullary PF values between moderate and severe CKD group, there was no statistically significant difference(P > 0.05).Conclusion 1. BOLD-f MRI can clearly show the kidney structure, non-invasively get kidney blood oxygen metabolism information, helping the evaluation of renal parenchyma blood oxygen changes for patients with CKD, especially the renal functional evaluation in the middle-late stage patients, provided some references for clinical value of the protection of residual renal function.2. DWI-IVIM model can provide more information from more microscopic diffusion of water molecules and the microcirculation perfusion, and detect the changes of micro-environment in the tissue caused by the changes of oxygen content, made a very good supplement and extension for the BOLD-f MRI.3. Combined BOLD-f MRI with DWI-IVIM model can be more comprehensive understanding of the functional information of the kidney metabolism, and provide an important reference value for the diagnosis and staging, treatment and prognosis of chronic kidney disease(CKD).