Premium
Efficient whole‐brain tract‐specific T 1 mapping at 3T with slice‐shuffled inversion‐recovery diffusion‐weighted imaging
Author(s) -
Leppert Ilana R.,
Andrews Daniel A.,
Campbell Jennifer S. W.,
Park Daniel J.,
Pike G. Bruce,
Polimeni Jonathan R.,
Tardif Christine L.
Publication year - 2021
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.28734
Subject(s) - diffusion mri , voxel , corticospinal tract , imaging phantom , white matter , corpus callosum , cingulum (brain) , physics , nuclear magnetic resonance , computer science , nuclear medicine , artificial intelligence , magnetic resonance imaging , anatomy , fractional anisotropy , biology , optics , medicine , radiology
Purpose Most voxels in white matter contain multiple fiber populations with different orientations and levels of myelination. Conventional T 1 mapping measures 1 T 1 value per voxel, representing a weighted average of the multiple tract T 1 times. Inversion‐recovery diffusion‐weighted imaging (IR‐DWI) allows the T 1 times of multiple tracts in a voxel to be disentangled, but the scan time is prohibitively long. Recently, slice‐shuffled IR‐DWI implementations have been proposed to significantly reduce scan time. In this work, we demonstrate that we can measure tract‐specific T 1 values in the whole brain using simultaneous multi‐slice slice‐shuffled IR‐DWI at 3T. Methods We perform simulations to evaluate the accuracy and precision of our crossing fiber IR‐DWI signal model for various fiber parameters. The proposed sequence and signal model are tested in a phantom consisting of crossing asparagus pieces doped with gadolinium to vary T 1 , and in 2 human subjects. Results Our simulations show that tract‐specific T 1 times can be estimated within 5% of the nominal fiber T 1 values. Tract‐specific T 1 values were resolved in subvoxel 2 fiber crossings in the asparagus phantom. Tract‐specific T 1 times were resolved in 2 different tract crossings in the human brain where myelination differences have previously been reported; the crossing of the cingulum and genu of the corpus callosum and the crossing of the corticospinal tract and pontine fibers. Conclusion Whole‐brain tract‐specific T 1 mapping is feasible using slice‐shuffled IR‐DWI at 3T. This technique has the potential to improve the microstructural characterization of specific tracts implicated in neurodevelopment, aging, and demyelinating disorders.