Diffusion tensor spectroscopy and imaging of the arcuate fasciculus
NeuroImage. 2008-01-01; 39(1): 1-9
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1. Neuroimage. 2008 Jan 1;39(1):1-9. Epub 2007 Sep 7.
Diffusion tensor spectroscopy and imaging of the arcuate fasciculus.
Upadhyay J(1), Hallock K, Ducros M, Kim DS, Ronen I.
(1)Department of Anatomy and Neurobiology, Center for Biomedical Imaging, Boston
University, School of Medicine, 715 Albany St. X-B01, Boston, MA 02118, USA.
The arcuate fasciculus (AF) is a fiber pathway in the human brain relevant for
language processes and has recently been characterized by means of diffusion
tensor tractography. The observations made concerning the left and right
hemisphere AF include a characterization of the trajectories and quantification
of physical properties such as fractional anisotropy, DTI-based fiber density and
volume. However, these observations were based on the diffusion of water, which
is not particular to either the intra- or extra-axonal compartments, and thus its
usefulness for tissue characterization is limited. If the diffusion properties
and in turn the geometric properties of only one tissue compartment can be
isolated and characterized, a better microstructural characterization of AF is
possible. In this study, water-based diffusion tensor probabilistic mapping was
first implemented to segment the AF. Subsequently, diffusion tensor spectroscopic
measurements of N-acetyl aspartate (NAA) were performed to measure the
intra-axonal specific diffusion in left and right AF. Diffusion properties of
NAA, which solely reflect the intra-axonal space, indicated possible leftward
asymmetry in axonal diameter, where those of water, which are not
compartment-specific, showed laterality to a lesser extent.
PMID: 17928238 [Indexed for MEDLINE]