| 主权项 |
1. A method of measuring diffusional anisotropy in diffusion-weighted magnetic resonance imaging comprising:
determining with at least one processor, an orientation diffusion function (ODF) of one or more fibers within a single voxel regardless of whether the fibers cross one another, wherein the ODF is defined by the integral magnitude of a probability of diffusion in a given direction with respect to the one or more fibers (Eqn 3), and the ODF mathematically appears as lobes having maxima peaks and minima troughs which are extrema values of maxima and minima of ODF magnitude, respectively, with respect to the one or more fibers; characterizing an aspect ratio of the determined ODF lobes by using the minima troughs (Ψmin) over the maxima peaks (Ψmax), wherein the Ψmin represents a low probability of diffusion in a particular direction and the Ψmax represents a high probability of diffusion in another particular direction; determining with the at least one processor, a multi-directional anisotropy (MDA) metric, with respect to each of the one or more fibers, within the single voxel, based on the aspect ratio (Ψmin/Ψmax)2/3 of the ODF without doing a decomposition of the one or more fibers, wherein the MDA metric reflects a ratio (μ) between the minima troughs and the maxima peaks of the determined ODF; and providing a storable or displayable metric output of the MDA, as an input, when performing diffusion weighted MRI on a magnetic resonance imaging scanner. |
