Assessing Renal Interstitial Fibrosis by Compartmental, Non-Compartmental, Model-Free Diffusion MRI and Their Corticomedullary Difference

Motivation: Non-invasive evaluation of chronic kidney disease (CKD) is of increasing value. Goal(s): This study aims to assess renal interstitial fibrosis (IF) using diffusion-based MRI approached and their corticomedullary difference (CMD) in CKD patients. Approach: MRI parameters from apparent diffusion coefficient (ADC), intra-voxel incoherent motion (IVIM), diffusion kurtosis imaging (DKI) and diffusion-relaxation correlated spectrum imaging (DR-CSI) were obtained both for renal cortex and medullary. CMD of these parameters were calculated. Results: Several diffusion-based MRI parameters are promising for differentiating between the mild and moderate-severe renal IF. CMD shows potential for the assessment of renal IF on a supplementary role. Impact: This study shows attempts on non-invasive assessment of renal interstitial fibrosis using several typical advanced model or model-free methods regarding diffusion MRI. Also, it illustrates the possible role of renal corticomedullary difference of these approaches in the assessment.