data_V1

The <file>data_V1</file> contains the first principal directions of the Orientation Distribution Function (ODF)of the fibres at each <file>data</file> voxel, based on the GQI method.

data

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).
 For estimating fibre orientations two methods have been
 implemented.  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.
 Reconstruction of orientation distribution function (ODF)
 profiles may be performed using the standard generalized
 q-sampling imaging (GQI) approach, Garyfallidis' GQI (GQI2)
 approach, or Aganj's variant of the Q-ball imaging (CSA-QBI)
 approach. 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.

Adelino da Silva

gdimap

Generalized Diffusion Magnetic Resonance Imaging

data_V1 function

The file <file>data.nii.gz</file> is in gzipped NIfTI format.
	The R-package <pkg>oro.nifti</pkg> is required to read NIfTI files.

data_V1: ODF First Principal Directions File

Description

Arguments

format

Details

References

See Also