Intravoxel Incoherent Motion To Assess Brain Microstructure And Perfusion In Hemodialysis Patients With End-stage Renal Disease

Objective:To evaluate the changes of brain microstructure and cerebral perfusion in patients with end-stage renal disease（ESRD）maintaining hemodialysis by intravoxel incoherent motion（IVIM）diffusion-weighted imaging,and to explore the effects of brain microstructure and perfusion changes on brain cognitive function in ESRD patients.Methods:From October 2020 to August 2021,a total of 40 patients with ESRD undergoing hemodialysis from the Department of Nephrology,Changzhou Second People’s Hospital affiliated to Nanjing Medical University were enrolled.At the same time,30 healthy people were included in the healthy control group.The Montreal Cognitive Assessment（Mo CA）was used for professional cognitive assessment of all subjects.Laboratory tests for hemoglobin,blood urea nitrogen,serum creatinine level and glomerular filtration rate（e GFR）were performed for all patients with ESRD within 24hours prior to the MRI scan,but not in the healthy control group.All subjects were scanned with conventional brain T₁-weighted sequence（T₁WI）,T₂-weighted sequence（T₂WI）,T₂-fluid attenuated inversion recovery（T₂-FLAIR）and IVIM sequence,and the slow apparent diffusion coefficient(ADC_slow),fast apparent diffusion coefficient(ADC_fast)and perfusion fraction（f）of corresponding brain regions of interest were calculated through post-processing.Intraclass correlation coefficient（ICC）was used to evaluate the consistency of IVIM derived parameter measurement among observers.The differences of IVIM derived parameters between ESRD group and control group were compared by independent sample t test or Mann-Whitney U test.Pearson correlation analysis was applied to analyze the relationships of the change of ADC_fast with neuropsychological and clinical characters.P<0.05 was considered statistically significant.For ESRD patients,the receiver operating characteristic（ROC）curve was used to select regions of interest that could be regarded as effective neuroimaging markers.Results:1.The statistical results of general data between ESRD group and healthy control group showed that there was no statistical difference in age and sex between the two groups（P>0.05）.The Mo CA score of ESRD group（24.00±4.18）was significantly lower than that of healthy control group（26.13±2.56）（P=0.007）.2.The comparison of IVIM parameters between the two groups showed that the ADC_slow values in the left frontal lobe,left hippocampus,bilateral temporal lobe and right occipital lobe in ESRD group were significantly higher than those in the healthy control group（P<0.05）.Compared with the healthy control group,significantly increased ADC_fast was observed in bilateral frontal lobe,parietal lobe,insular lobe,temporal lobe,hippocampus and occipital lobe of the ESRD group（P<0.001）.The f value between the two groups had no statistical difference in each brain region of interest（P>0.05）.3.From Pearson correlation analysis,a negative correlation was found between the Mo CA scores and ADC_fast in the right frontal lobe（r=-0.324,P=0.041）and the insular lobe of patients（r=-0.319,P=0.045）.ADC_fast in the right parietal lobe（r=0.408,P=0.009）and the right hippocampus（r=0.324,P=0.041）of patients were positively correlated with hemoglobin levels.4.Using ROC analysis,ADC_fast in the right frontal lobe,insular lobe,hippocampus,and parietal lobe separately showed fair to good efficacy in differentiating ESRD patients with cognitive dysfunction from healthy subjects,with the area under the ROC ranging from 0.853 to 0.903.Conclusion:The microstructure and perfusion of the brain were impaired in ESRD patients,showing the increase of ADC_slow value and ADC_fast value in some brain regions.Moreover,the sensitivity of ADC_fsat value is higher than that of ADC_slow value in evaluating the cognitive dysfunction of ESRD hemodialysis patients.ADC_fastof the right frontal lobe,insular lobe,hippocampus,and parietal lobe could be effective biomarker for evaluating cognitive impairment in ESRD hemodialysis patients.