Diffusion MRI-based Explicit Microstructural Imaging Analysis

Motivation: Current model fitting of dMRI-based cell size imaging is implicit, which is time-consuming and limits the reproducibility of imaging results, hindering the promotion of such techniques in applications. Goal(s): Improve basic mathematical framework and obtain an explicit solution. Approach: Designed special sequences to make restricted ADC satisfy linear relationships with cell radius, then derive explicit expressions for microstructural parameters. Results: A series of sequences that meet the requirements were obtained, and an explicit cell size imaging method EMIA was developed. Simulations show that EMIA can avoid unstable model fitting, greatly reduces computational time, and has clinical potential in applications. Impact: Clinical applications of cell size imaging are limited by current implicit model fitting, which is time-consuming and poorly reproducible. We developed an explicit imaging method by designing diffusion-weighted sequences, improving unstable fitting and shortening computational time.