Hi everybody, a very happy new year, with the hope 2011 will bring us near to our goals. I have a very simple question about surfaces in freesurfer. As i posted previously, i am trying to match white matter surface RAS coordinates with the corresponding anatomical volume. My attempt is to save an externally tessellated mesh (in scanner voxel coordinates) into RAS coordinates which match the volume.

1 - I first save the MRI T1 volume with save_mgh routine (i get the info about the vox2ras matrix by doing mri_info --vox2ras mri_file.nii) 2 - Then i save the surface (after transforming the voxel coordinates with the same vox2ras matrix used before for the volume) with write_surf 3 - Then i visualize volume and surface together with the tkmedit tool. Even if surface and volume seem to have correct projection alignment (coronal is coronal for both) there is evidently a mismatch in the superimposition of mesh and volumetric structures. The volume dimensions are 256X256X192 and is a monkey brain. Any suggestion to get me out of this local minimum?

Greeting to everybody and congratulations for the nice toolbox Cristiano