Dear Freesurfer,

I have a surface file containing values of a cortical myelination index (rh.MS075_CME.mgh), and a lesion mask (rh.surf_CL03.mgh)

What I need to do is:

- Masking the surface file with the lesion mask, to create a new lesion mask that contains the myelination index values from rh.MS075_CME.mgh;

- Assess the percentage (or also the absolute number) of vertices that are under a certain threshold of myelination index values whithin the new lesion mask.

What is the best way to do this?

Thank you,

Vale