Romer-EPTI: Rotating-View Motion-Robust Super-Res EPTI for SNR-Efficient Distortion-Free In-Vivo Mesoscale dMRI & Microstructure Imaging

Motivation: Diffusion MRI faces challenges in achieving higher spatial resolution or b-values, including limited SNR, compromised image quality, and vulnerability to motion. Goal(s): To overcome these major challenges and achieve efficient and robust high-resolution in-vivo dMRI and microstructure imaging. Approach: We introduced Romer-EPTI, an SNR-efficient motion-robust acquisition technique, providing significant gain in SNR efficiency (e.g., 5×), high robustness to motion, and distortion-free imaging with minimal blurring and slab-boundary artifacts. Results: We successfully achieved whole-brain in-vivo dMRI at mesoscale resolutions at both 3T (500-μm-iso) and 7T (485-μm-iso) using Romer-EPTI, and also demonstrated its high efficiency in high b-value microstructure imaging. Impact: This study introduces a novel Romer-EPTI technique that addresses key challenges in in-vivo diffusion MRI acquisition to enable high-resolution dMRI at mesoscale spatial resolutions and efficient high-b-value microstructure imaging.