mrclusterstats

Synopsis

Voxel-based analysis using permutation testing and threshold-free cluster enhancement

Usage

mrclusterstats [ options ]  input design contrast mask output
  • input: a text file containing the file names of the input images, one file per line
  • design: the design matrix, rows should correspond with images in the input image text file
  • contrast: the contrast matrix, only specify one contrast as it will automatically compute the opposite contrast.
  • mask: a mask used to define voxels included in the analysis.
  • output: the filename prefix for all output.

Options

Options for permutation testing

  • -notest don’t perform permutation testing and only output population statistics (effect size, stdev etc)
  • -nperms num the number of permutations (Default: 5000)
  • -permutations file manually define the permutations (relabelling). The input should be a text file defining a m x n matrix, where each relabelling is defined as a column vector of size m, and the number of columns, n, defines the number of permutations. Can be generated with the palm_quickperms function in PALM (http://fsl.fmrib.ox.ac.uk/fsl/fslwiki/PALM). Overrides the nperms option.
  • -nonstationary perform non-stationarity correction
  • -nperms_nonstationary num the number of permutations used when precomputing the empirical statistic image for nonstationary correction (Default: 5000)
  • -permutations_nonstationary file manually define the permutations (relabelling) for computing the emprical statistic image for nonstationary correction. The input should be a text file defining a m x n matrix, where each relabelling is defined as a column vector of size m, and the number of columns, n, defines the number of permutations. Can be generated with the palm_quickperms function in PALM (http://fsl.fmrib.ox.ac.uk/fsl/fslwiki/PALM) Overrides the nperms_nonstationary option.

Options for controlling TFCE behaviour

  • -tfce_dh value the height increment used in the tfce integration (default: 0.1)
  • -tfce_e value tfce extent exponent (default: 0.5)
  • -tfce_h value tfce height exponent (default: 2)

Additional options for mrclusterstats

  • -negative automatically test the negative (opposite) contrast. By computing the opposite contrast simultaneously the computation time is reduced.
  • -threshold value the cluster-forming threshold to use for a standard cluster-based analysis. This disables TFCE, which is the default otherwise.
  • -connectivity use 26-voxel-neighbourhood connectivity (Default: 6)

Standard options

  • -info display information messages.
  • -quiet do not display information messages or progress status.
  • -debug display debugging messages.
  • -force force overwrite of output files. Caution: Using the same file as input and output might cause unexpected behaviour.
  • -nthreads number use this number of threads in multi-threaded applications (set to 0 to disable multi-threading)
  • -failonwarn terminate program if a warning is produced
  • -help display this information page and exit.
  • -version display version information and exit.

References

  • If not using the -threshold command-line option:Smith, S. M. & Nichols, T. E. Threshold-free cluster enhancement: Addressing problems of smoothing, threshold dependence and localisation in cluster inference. NeuroImage, 2009, 44, 83-98
  • If using the -nonstationary option:Salimi-Khorshidi, G. Smith, S.M. Nichols, T.E. Adjusting the effect of nonstationarity in cluster-based and TFCE inference. Neuroimage, 2011, 54(3), 2006-19

Author: David Raffelt (david.raffelt@florey.edu.au)

Copyright: Copyright (c) 2008-2017 the MRtrix3 contributors

This Source Code Form is subject to the terms of the Mozilla Public License, v. 2.0. If a copy of the MPL was not distributed with this file, you can obtain one at http://mozilla.org/MPL/2.0/.

MRtrix is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

For more details, see http://www.mrtrix.org/.