Hi Katherine - If you mean the .trk format, that's not for storing labels, it's for storing tractography streamlines (i.e., a bunch of curves that are stored as sequences of x,y,z point coordinates). You can convert the FreeSurfer labels to nifti volumes, and see if the software that you're trying to use for graph analysis can read in the labels in that format.

TRACULA does not do whole brain tractography, it's for reconstructing specific pathways. If you want to do whole brain tensor tractography and save the results in .trk format, you can use the dtk/trackvis.

There are two different inputs that you need for your graph analysis, the tracts in .trk format and the labels that will be the end points of the tracts - you have to find out what the format of the latter needs to be.

a.y

________________________________ From: Katherine Damme katherine.damme@gmail.com Sent: Thursday, February 22, 2018 8:45:20 PM To: Anastasia Yendiki; Freesurfer support list Subject: FreeSurfer Labels To Diffusion Toolkit/TrackVis

Hello Everyone,

I would like to use the FreeSurfer labels for fMRI and DTI in graph theory analyses. I am attempting to use UMPChttps://github.com/jbrown81/umcp to generate the graphs, which requires that the diffusion tensor imaging be in .dtk form. However, I have been struggling to get the FreeSurfer labels into the .dtk space.

While I have found this https://surfer.nmr.mgh.harvard.edu/fswiki/FreeSurferTrackVisTransforms website suggesting a method for moving from the dtk space to FreeSurfer, it doesn't appear to be a reversible process.

Leading me to ask:

1. Is there a way to generate graphs from TRACULA?

or

2. How can I transform the labels or dlabels into dtk space?

Thank you for any help on this topic!

Kate Damme