Dear all,
I am trying to find vertices corresponding to (or as near as possible) a given set of MNI coordinates. I use freesurfer_read_surf and freesurfer_surf2tal to get the MNI coordinates of the vertices - however, place of the origin (0,0,0) in the brain seems to vary between subjects - especially the origin of our subjects is different from that of the given set, which of course makes it terribly difficult to find corresponding vertices.
So, I would like to know if there is a anatomically fixed origin for the MNI coordinates given by freesurfer_surf2tal and where it is. Of course I would also be happy for any other pieces of advice to get through this problem. The Freesurfer analysis for our subjects is done during a relatively long period of time (between 2007 and 2010) so one possible reason for the subject-to-subject differences might also be a change of e.g. MNI template used by the Freesurfer - has there been any changes of that kind?
Many thanks already in advance!
Best regards, Onerva Korhonen