High-Resolution Diffusion Weighted MRI Enabled by Multi-Shot EPI with Multiplexed Sensitivity-Encoding

Nan-kuei Chen¹, Arnaud Guidon¹, Hing-Chiu Chang¹, Allen W. Song¹

DWI data have been mostly acquired with single-shot EPI with limited spatial resolution. Multi-shot EPI could potentially achieve higher spatial resolution and fidelity, but is susceptible to aliasing artifacts due to phase inconsistencies among excitations. Although the shot-to-shot phase variations may be corrected with navigator echoes, the residual artifacts may be pronounced when there exist local and nonlinear motions. To address these challenges, a novel multi-shot DWI technique is developed here to reliably and inherently correct nonlinear shot-to-shot phase variations without navigator echoes. This technique enables very high-resolution DWI mapping of human white matter architecture.