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Abstract #3589

Multi-Directional Anisotropy Obtained from the Diffusion Propagator

Ek T. Tan1, Luca Marinelli1, Christopher J. Hardy1, Kevin F. King2, Jonathan I. Sperl3, Marion I. Menzel3

1GE Global Research, Niskayuna, NY, United States; 2GE Healthcare, Waukesha, WI, United States; 3GE Global Research, Garching, Germany

Diffusional anisotropy is an important indicator for axonal integrity, but conventional DTI-based fractional anisotropy (FA) is not well-suited to describing anisotropy of multi-directional diffusivities. A multi-directional anisotropy (MDA) metric was proposed, which is analytically and experimentally shown to be equivalent to FA in single-fibers. In double-fibers, the mean MDA was higher than FA, while the variation of MDA was smaller than FA. In addition, fiber counts can be inferred from the diffusion propagator. The availability of both MDA and fiber counting can be useful for multi-parametric analysis of anisotropy in crossing-fiber and gray matter regions.

Keywords

absolute acceleration acquisition addition adequately allow analytically anisotropic anisotropy applied array arrows asset assumed assumes behavior bimodal brain cerebellum channel clinical clustered clustering coil coincided components compressed computed corpus correlation count crossing defined demonstrating describe detected determined diffusion diffusional diffusivity directional disorders distribution double equal equivalent extent fiber fibers fold fractional function general generalized global gray hardy hence highly in vivo increasing indicate indication individual inferred integrity intervals king knowledge linearity longer maximal maybe measures metric minimal noise notably novel orientation parametric partial peaks perpendicular plots primarily principal projections propagator proportional proposed random reduced requires samples sensing setting simulated simulations slices space spectrum subjects suggest superior taken tensor troughs variance variation volume yielding