Chronic kidney disease: Pathological and functional evaluation with intravoxel incoherent motion diffusion-weighted imaging

BackgroundBecause chronic kidney disease (CKD) is a worldwide problem, accurate pathological and functional evaluation is required for planning treatment and follow-up. Intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI) can assess both capillary perfusion and tissue diffusion and may be helpful in evaluating renal function and pathology. PurposeTo evaluate functional and pathological alterations in CKD by applying IVIM-DWI. Study TypeProspective study. SubjectsIn all, 72 CKD patients who required renal biopsy and 20 healthy volunteers. Field Strength1.5T. AssessmentAll subjects underwent IVIM-DWI of the kidneys, and image analysis was performed by two radiologists. The mean values of true diffusion coefficient (D), pseudo diffusion coefficient (D*), and perfusion fraction (f) were acquired from renal parenchyma. Correlation between IVIM-DWI parameters and estimated glomerular filtration rate (eGFR), as well as pathological damage, were assessed. Statistical TestsOne-way analysis of variance (ANOVA), paired sample t-test and Spearman correlation analysis. ResultsThe paired sample t-test revealed that IVIM-DWI parameters were significantly lower in medulla than cortex for both patients and controls (P < 0.01). Regardless of whether eGFR was reduced, ANOVA revealed that f values of renal parenchyma were significantly lower in patients than controls (P < 0.05). Spearman correlation analysis revealed that there were positive correlations between eGFR and D (cortex, r=0.466, P < 0.001; medulla, r=0.491, P < 0.001), and between eGFR and f (cortex, r=0.713, P < 0.001; medulla, r=0.512, P < 0.001). Negative correlations were found between f and glomerular injury (cortex, r=-0.773, P < 0.001; medulla, r=-0.629, P < 0.001), and between f and tubulointerstitial lesion (cortex, r=-0.728, P < 0.001; medulla, r=-0.547, P < 0.001). Data ConclusionIVIM-DWI might be feasible for noninvasive evaluation of renal function and pathology of CKD, especially in detection of renal insufficiency at an early stage. Level of Evidence: 1 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2018;47:1251-1259.