dtiData {dti}R Documentation

Creates a dtiData object

Description

This function creates a dtiData object from an imagefile, where the diffusion weighted data is given as 2-byte integer.

Usage

dtiData(gradient, imagefile, ddim, xind = NULL, yind = NULL, zind = NULL, level = 0, mins0value = 0, maxvalue = 10000, voxelext = c(1, 1, 1),
        orientation = c(1, 3, 5))

Arguments

gradient matrix of diffusion gradients (including zero gradients for S0 images
imagefile filename for image data (binary 2Byte integers)
ddim dimension of image cube (3D)
xind subindex for x-direction
yind subindex for y-direction
zind subindex for z-direction
level determine mins0value as quantile of positive S)-values
mins0value set voxel in S0-images with values less than level inactive
maxvalue set voxel with values larger than maxvalue inactive
voxelext voxelextensions in coordinate directions.
orientation orientations of data coded as in AFNI

Details

This function creates a dtiData object from an imagefile, where the diffusion weighted data is given as 2-byte integer. This image file has to be prepared by the user and there is not yet a function to do this within the package. Simply use writeBin to write out first all S0 images and than all Si images. The gradient should be created according to this order. Run the demo in order to have an example, how to do this!

Value

An object of class dtiData.

Author(s)

Karsten Tabelow tabelow@wias-berlin.de, J"org Polzehl polzehl@wias-berlin.de

References

K. Tabelow, J. Polzehl, H.U. Voss, and V. Spokoiny. Diffusion Tensor Imaging: Structural adaptive smoothing, NeuroImage 39(4), 1763-1773 (2008).

http://www.wias-berlin.de/projects/matheon_a3/

See Also

dtiTensor, dtiData

Examples

## Not run: demo(dti_art)

[Package dti version 0.5-4 Index]