dti (version 1.2-0.1)

tracking-methods: Methods for Function `tracking' in Package `dti'

Description

The function provides fiber tracking of "dtiTensor", "dtiIndices", and "dwiMixtensor" objects and methods for fiber manipulations.

Usage

## S3 method for class 'dtiTensor':
tracking(obj, roix=NULL, roiy=NULL, roiz=NULL, mask=NULL,
                    method="LINEPROP", minfa=0.3, maxangle=30, subsample = 1)
## S3 method for class 'dtiIndices':
tracking(obj, roix=NULL, roiy=NULL, roiz=NULL, mask=NULL,
                    method="LINEPROP", minfa=0.3, maxangle=30, subsample = 1)
## S3 method for class 'dwiMixtensor':
tracking(obj, roix=NULL, roiy=NULL, roiz=NULL, mask=NULL,
                    method="LINEPROP", minfa=0.3, maxangle=30, subsample = 1, 
                    mincompartsize = 0)
## S3 method for class 'dwiFiber':
selectFibers(obj, roix=NULL, roiy=NULL, roiz=NULL, mask=NULL,
                    minlength=1)
## S3 method for class 'dwiFiber':
reduceFibers(obj, maxdist=1, ends=TRUE)
## S3 method for class 'dwiFiber,dwiFiber':
combineFibers(obj, obj2)
## S3 method for class 'dwiFiber,dwiFiber':
touchingFibers(obj, obj2, maxdist=1, combine=FALSE)

Arguments

obj

An object of class "dtiTensor", "dtiIndices", or "dwiMixtensor" for tracking() and "dwiFiber" for selectFiber(), conbineFibers().

obj2

An object of class "dwiFiber" for combineFibers().

roix

Indices defining the ROI in x direction. Currently min/max is used to define ROIx

roiy

Indices defining the ROI in y direction. Currently min/max is used to define ROIy

roiz

Indices defining the ROI in z direction. Currently min/max is used to define ROIz

mask

Mask defining seed points for tracking

method

Method for fibre tracking. "LINEPROP" is simple line propagation algorithm which is the default.

minfa

Minimal FA to follow the tracks. default 0.3

maxangle

Maximal angle between fiber in adjacent voxels. default 30 degree.

subsample

Subsampling order of the data to get more dense fibre tracks. Note, that objects become very(!) large.

minlength

Minimal length of fibers to be selected.

maxdist

Maximal supremum distance between fibers in mm

ends

Logical: Use only endpoints of shorter fibers for distance (TRUE) or compute distances using full fiber-length (FALSE). Default (TRUE) removes more fibers and is significantly faster.

mincompartsize

Minimal size of a compartment in dwiMixtensor that will be used in fiber tracking.

combine

If combine=TRUE fibers selected from obj are combined with the fibers from obj2.

Value

• The function returns an object of class dwiFiber.

See Also

dtiTensor,dtiIndices,dwiFiber, show3d, summary, print