Hong-Hsi Lee1, Gregory Lemberskiy1, Els Fieremans1, and Dmitry S. Novikov1
Finite pulse duration $$$\delta$$$ of diffusion
gradient has typically been a source of bias for quantifying microstructure.
Here, we suggest to use the diffusivity dependence on $$$\delta$$$ to reveal
the correlation length of the fiber packing, an essential μm–level
characteristic of microstructure, thereby turning the finite pulse duration to
our advantage. We validate our method in a fiber phantom that mimics an axonal
packing geometry, and the estimated correlation length matches the fiber radius.
Future work will focus on the evaluation of its potential as biomarkers for in vivo brain scans, such as axonal
density and outer axonal diameters.