Evaluation of Fiber Radius Mapping using Diffusion MRI Under Clinical System Constraints

Chun-Hung Yeh^1,2, Irina Kezele¹, Daniel Alexander³, Benoit Schmitt¹, Jing-Rebecca Li¹, Denis Le Bihan¹, Ching-Po Lin², Cyril Poupon¹

We assessed the feasibility in mapping white matter fiber radius using diffusion MRI on clinical scanners. We performed Monte Carlo simulations on water diffusion in various fiber radii, and evaluated a list of conventional pulsed-gradient spin-echo imaging protocols with the constraints on the gradient system capability. Within a clinical acceptable acquisition time of 30 minutes, we observed that using three q-space sampling shells with moderate to high b-values is potentially feasible to accurately estimate fiber radii ranging from 2-6 um. Meanwhile we provided a guideline to setup clinical protocols for the purpose of fiber radius estimation.