dti (version 1.2-6.1)

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

Description

The method calculates, in each voxel, the mean diffusivityfrom the DWI data contained in an object of class "dtiData" or from the estimated diffusion tensor in an object of class "dtiThensor"

Usage

# S4 method for dtiData
dwiMD(object, eps=.05)
  # S4 method for dtiTensor
dwiMD(object)

Arguments

object

Object of class "dtiData" or class "dtiTensor"

eps

In case of an "dtiData" object the method searches for three approximately orthogonal gradient directions. The mean diffusivity is then calculated using the observed apparent diffusion coefficients for these gradients. The search is terminated if a measure for deviation from orthogonality is smaller than eps

Value

An array of mean diffusivity values.

Methods

obj = "ANY"

Returns a warning.

obj = "dtiData"

calculates mean diffusivity from 3 approximately orthogonal gradient directions

obj = "dtiTensor"

calculates mean diffusivity from estimated diffusion tensors

References

J. Polzehl and K. Tabelow, Beyond the diffusion tensor model: The package dti, Journal of Statistical Software, 44(12), 1-26 (2011).

J. Polzehl and K. Tabelow, Structural adaptive smoothing in diffusion tensor imaging: The R package dti, Journal of Statistical Software, 31(9) 1-24 (2009).

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

See Also

dtiData, readDWIdata, dtiIndices-methods, medinria, '>dtiData, '>dtiTensor '>dwiMixtensor

Examples

# NOT RUN {
  
# }
# NOT RUN {
demo(dti_art)
# }