dti (version 0.5-4)

dtiData: 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

Value

• An object of class dtiData.

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!

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

demo(dti_art)