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Characterization of white matter fiber bundles with T 2 * relaxometry and diffusion tensor imaging
Author(s) -
Cherubini Andrea,
Péran Patrice,
Hagberg Gisela Elisabeth,
Varsi Ambra Erika,
Luccichenti Giacomo,
Caltagirone Carlo,
Sabatini Umberto,
Spalletta Gianfranco
Publication year - 2009
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.21978
Subject(s) - relaxometry , diffusion mri , nuclear magnetic resonance , white matter , characterization (materials science) , diffusion , fiber , materials science , tensor (intrinsic definition) , magnetic resonance imaging , chemistry , physics , mathematics , medicine , spin echo , composite material , radiology , pure mathematics , nanotechnology , thermodynamics
In this study, diffusion tensor imaging (DTI) and T 2 *multiecho relaxometry were combined in 30 healthy subjects at 3T, with the aim of characterizing the spatial distribution of relaxation rates in white matter (WM). Region of interest (ROI) analysis was performed in 23 different fiber tracts automatically defined in standard space. Spearman rank analysis was performed on regional values of T 2 * , fractional anisotropy (FA), and radial diffusivity (RD). A strong relationship was observed between the location and direction of fiber bundles and relaxation rates, and adjacent fiber bundles with similar orientation showed very different relaxation rates. Moreover, while relaxation rates varied largely between different fiber tracts, variation of the same parameter within the same anatomical fiber bundle across individuals was remarkably limited. The rich variability of relaxation rates in WM and their complex relationship with DTI data suggested that the two techniques might be sensitive to complementary characteristics of myelin structure. This has tremendous potential to allow for a more detailed understanding of brain development and pathology, in particular in the context of age‐related cognitive decline. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.