pipeline_dbm.pl

deformation-based morphometry from nonlinear transforms

pipeline_dbm.pl <input.xfm> <output_dbm> [options]

DESCRIPTION

pipeline_dbm.pl performs deformation-based morphometry (DBM) by computing a smoothed Jacobian determinant map from a nonlinear transformation file. The resulting DBM map represents local volume changes relative to a reference model, where values greater than 1 indicate local expansion and values less than 1 indicate local contraction.

The nonlinear transformation is typically produced by pipeline_nlr.pl and maps a subject’s brain to a standard template. The Jacobian determinant field is blurred with a Gaussian kernel whose full-width at half-maximum (FWHM) is controlled by the –fwhm option (default 8 mm).

OPTIONS

--verbose
Print progress information during processing.
--clobber
Overwrite the output file if it already exists.
--fwhm <f>
Full-width at half-maximum of the Gaussian blurring kernel applied to the Jacobian determinant map, in millimetres. Default is 8.
--model <file>
Reference model volume used to define the output sampling grid.

EXAMPLES

Compute a DBM map with default 8 mm smoothing:

pipeline_dbm.pl nl_transform.xfm dbm_output.mnc

Compute a DBM map with 4 mm smoothing:

pipeline_dbm.pl nl_transform.xfm dbm_output.mnc --fwhm 4

Compute a DBM map with a specific model and clobber:

pipeline_dbm.pl nl_transform.xfm dbm_output.mnc \
  --model icbm_avg_152_t1_tal_nlin_symmetric_VI.mnc --clobber

AUTHOR

Vladimir S. Fonov - McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University.

COPYRIGHTS

Copyright © McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University.

SEE ALSO

pipeline_jacobian.pl, pipeline_nlr.pl