Title
The influence of complex white matter architecture on the mean diffusivity in diffusion tensor MRI of the human brain.
Abstract
In diffusion tensor magnetic resonance imaging (DT-MRI), limitations concerning complex fiber architecture (when an image voxel contains fiber populations with more than one dominant orientation) are well-known. Fractional anisotropy (FA) values are lower in such areas because of a lower directionality of diffusion on the voxel-scale, which makes the interpretation of FA less straightforward. Moreover, the interpretation of the axial and radial diffusivities is far from trivial when there is more than one dominant fiber orientation within a voxel. In this work, using (i) theoretical considerations, (ii) simulations, and (iii) experimental data, it is demonstrated that the mean diffusivity (or the trace of the diffusion tensor) is lower in complex white matter configurations, compared with tissue where there is a single dominant fiber orientation within the voxel. We show that the magnitude of this reduction depends on various factors, including configurational and microstructural properties (e.g., the relative contributions of different fiber populations) and acquisition settings (e.g., the b-value). These results increase our understanding of the quantitative metrics obtained from DT-MRI and, in particular, the effect of the microstructural architecture on the mean diffusivity. More importantly, they reinforce the growing awareness that differences in DT-MRI metrics need to be interpreted cautiously.
Year
DOI
Venue
2012
10.1016/j.neuroimage.2011.09.086
NeuroImage
Keywords
Field
DocType
Diffusion tensor MRI,Crossing fibers,Complex fiber architecture,Trace,Mean diffusivity
Voxel,Developmental psychology,Magnitude (mathematics),Diffusion MRI,Fiber,White matter,Fractional anisotropy,Psychology,Thermal diffusivity,Tractography
Journal
Volume
Issue
ISSN
59
3
1053-8119
Citations 
PageRank 
References 
19
0.92
12
Authors
5
Name
Order
Citations
PageRank
Sjoerd B. Vos1864.04
Derek K. Jones265548.55
Ben Jeurissen343718.21
Max A Viergever47946833.77
Alexander Leemans523720.37