MRI BIOPHYSICS GROUP

bridging the micro-macro gap with diffusion MRI

TE dependent Diffusion Imaging (TEdDI) distinguishes between compartmental T2 relaxation times.

TitleTE dependent Diffusion Imaging (TEdDI) distinguishes between compartmental T2 relaxation times.
Publication TypeJournal Article
Year of Publication2018
AuthorsVeraart, J, Novikov, DS, Fieremans, E
JournalNeuroimage
Volume182
Pagination360–369
Date PublishedNov
ISSN1095-9572 (Electronic); 1053-8119 (Linking)
Keywords*Diffusion, *Modeling, *MRI, *Transverse relaxation
Abstract

Biophysical modeling of macroscopic diffusion-weighted MRI signal in terms of microscopic cellular parameters holds the promise of quantifying the integrity of white matter. Unfortunately, even fairly simple multi-compartment models of proton diffusion in the white matter do not provide a unique, biophysically plausible solution. Here we report a nontrivial diffusion MRI signal dependence on echo time (TE) in human white matter in vivo. We demonstrate that such TE dependence originates from compartment-specific T2 values and that it is a promising "orthogonal measure" able to break the degeneracy in parameter estimation, and to yield important relaxation metrics robustly. We thereby enable the precise estimation of the intra- and extra-axonal water T2 relaxation times, which is precluded by a limited signal-to-noise ratio when using multi-echo relaxometry alone.

DOI10.1016/j.neuroimage.2017.09.030
PubMed ID28935239
Research Category: 

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