MRI BIOPHYSICS GROUP

bridging the micro-macro gap with diffusion MRI

Rotationally-invariant mapping of scalar and orientational metrics of neuronal microstructure with diffusion MRI.

TitleRotationally-invariant mapping of scalar and orientational metrics of neuronal microstructure with diffusion MRI.
Publication TypeJournal Article
Year of Publication2018
AuthorsNovikov, DS, Veraart, J, Jelescu, IO, Fieremans, E
JournalNeuroimage
Volume174
Pagination518–538
Date PublishedJul
ISSN1095-9572 (Electronic); 1053-8119 (Linking)
Keywords*Diffusion, *Microstructure, *MRI, *Neurites, *Orientational dispersion
Abstract

We develop a general analytical and numerical framework for estimating intra- and extra-neurite water fractions and diffusion coefficients, as well as neurite orientational dispersion, in each imaging voxel. By employing a set of rotational invariants and their expansion in the powers of diffusion weighting, we analytically uncover the nontrivial topology of the parameter estimation landscape, showing that multiple branches of parameters describe the measurement almost equally well, with only one of them corresponding to the biophysical reality. A comprehensive acquisition shows that the branch choice varies across the brain. Our framework reveals hidden degeneracies in MRI parameter estimation for neuronal tissue, provides microstructural and orientational maps in the whole brain without constraints or priors, and connects modern biophysical modeling with clinical MRI.

DOI10.1016/j.neuroimage.2018.03.006
PubMed ID29544816
Research Category: 

Scholarly Lite is a free theme, contributed to the Drupal Community by More than Themes.