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Diffusion anisotropy in subcortical white matter and cortical gray matter: Changes with aging and the role of CSF‐suppression
Author(s) -
Bhagat Yusuf A.,
Beaulieu Christian
Publication year - 2004
Publication title -
journal of magnetic resonance imaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.563
H-Index - 160
eISSN - 1522-2586
pISSN - 1053-1807
DOI - 10.1002/jmri.20102
Subject(s) - fractional anisotropy , white matter , diffusion mri , cerebrospinal fluid , psychology , neuroscience , medicine , nuclear magnetic resonance , magnetic resonance imaging , physics , radiology
Purpose To determine the relevance of cerebrospinal fluid (CSF)‐suppression for the measurement of diffusion anisotropy in well‐localized areas of the brain, particularly the subcortical white matter (WM) within the gyri and cortical gray matter (GM), in young and elderly subjects, and to assess the changes of water diffusivity in the brain with normal aging. Materials and Methods Quantitative measures of anisotropy in 26 regions, including subcortical WM (i.e., in the gyri), cortical GM, major deep WM, and deep GM regions of young (21–25 years, N = 8) and elderly (61–74 years, N = 10) normal volunteers, were assessed with CSF‐suppressed diffusion tensor imaging (DTI) relative to standard DTI. Results CSF‐suppressed DTI demonstrated significant increases in fractional anisotropy (FA) of 3–12% in the young and 2–14% in the elderly groups with the largest changes being in the subcortical WM of the gyri. Furthermore, FA decreased by 10–19% in the subcortical WM of the gyri of the elderly subjects relative to the young, primarily due to increases in the perpendicular diffusivity, λ 3 , with age. Conclusion CSF‐suppressed DTI yields more accurate measures of quantitative anisotropy in cortical and subcortical brain regions. Reductions of anisotropy with aging were predominantly observed in subcortical WM of the gyri. J. Magn. Reson. Imaging 2004;20:216–227. © 2004 Wiley‐Liss, Inc.