Finding % of tracts that cross significant voxels in tractogram

Hi MRtrix3 Team,

I’m doing a tractography analysis where I’m interested in finding out if a percentage of tracks in my tractogram have crossed certain significant voxels (I have MNI coordinates for these ROIs). As I’m unfamiliar with this, does anyone know how I could go about this?

Many thanks

Probably the simplest approach here is to generate a mask ROI of your selected voxels, then run something like:

tckedit your_tracks.tck -include your_ROI.nii output.tck

and then compare the count field in the output of tckinfo your_tracks.tck and tckinfo output.tck – i.e. the number of streamlines in the orignal tractogram, compared to the number that were selected by using your_ROI.nii as an inclusion ROI.

For anything more complex than that (e.g. if you have multiple ROIs), you could also try tck2connectome.

Thank you so much for your help! It has worked wonders.