Title
Micro-compartment specific T relaxation in the brain.
Abstract
MRI at high field can be sensitized to the magnetic properties of tissues, which introduces a signal dependence on the orientation of white matter (WM) fiber bundles relative to the magnetic field. In addition, study of the NMR relaxation properties of this signal has indicated contributions from compartmentalized water environments inside and outside the myelin sheath that may be separable. Here we further investigated the effects of water compartmentalization on the MRI signal with the goal of extracting compartment-specific information. By comparing MRI measurements of human and marmoset brain at 7T with magnetic field modeling, we show that: (1) water between the myelin lipid bilayers, in the axonal, and in the interstitial space each experience characteristic magnetic field effects that depend on fiber orientation (2) these field effects result in characteristic relaxation properties and frequency shifts for these compartments; and (3) compartmental contributions may be separated by multi-component fitting of the MRI signal relaxation (i.e. decay) curve. We further show the potential application of these findings to the direct mapping of myelin content and assessment of WM fiber integrity with high field MRI.
Year
DOI
Venue
2013
10.1016/j.neuroimage.2013.03.005
NeuroImage
Keywords
DocType
Volume
Water compartment,T2⁎ relaxation,Frequency shift,White matter,Brain,Demyelination
Journal
77
ISSN
Citations 
PageRank 
1053-8119
23
1.04
References 
Authors
13
7
Name
Order
Citations
PageRank
Pascal Sati1272.21
Peter van Gelderen240335.74
Afonso C. Silva322018.38
Daniel S. Reich420915.94
Hellmut Merkle58412.39
Jacco A de Zwart633330.78
Jeff H. Duyn783948.39