gdimap: Generalized Diffusion Magnetic Resonance Imaging
Diffusion anisotropy has been used to characterize white
matter neuronal pathways in the human brain, and infer global
connectivity in the central nervous system. The package
implements algorithms to estimate and visualize the orientation
of neuronal pathways in model-free methods (q-space imaging
methods). An optimized reconstruction technique based on the
generalized q-sampling imaging (GQI) approach is adopted to
reconstruct orientation distribution function (ODF) profiles.
Two methods have been implemented to estimate fibre
orientations. One method implements fibre orientation detection
through local maxima extraction. A second more robust method is
based on directional statistical clustering of ODF voxel data.
Fibre orientations in multiple fibre voxels are estimated using
a mixture of von Mises-Fisher (vMF) distributions. This
statistical estimation procedure is used to resolve crossing
fibre configurations. Procedures for the visualization of
RGB-maps, line-maps and glyph-maps of real diffusion magnetic
resonance imaging (dMRI) data-sets are included in the package.