Hi Sean - Do you mean that the streamlines go through non-brain voxels? You could you a slightly dilated version of the aparc+aseg as a mask. You can use bbregister to map it to the subject's DWI space.
a.y
On Mon, 9 Sep 2013, Sean Hatton wrote:
Hello FS Gurus,
I would like to export FS labels as seed regions for deterministic tractography in TrackVis (probabilistic is not appropriate in this investigation). I run mri_label2vol with “--proj abs -4 0 .1” to try and grow the label into the WM and exclude GM. While I get a biologically plausible ROIs and plenty of good streamlines, I do get some stray streamlines that jump across the sulci into adjacent gyri which (I have read) is an artefact of seeding from GM. Have I got the right approach? Should I create an inverse intracranial volume mask as an exclusion mask? Something else?
Kind regards,
Sean Hatton Brain & Mind Research Institute University of Sydney, Australia. _______________________________________________ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer