What do you mean by the "actual 3d coordiantes in the mesh"? The RAS
coord is the MNI305 coord. You can have tksurfer display it with
View->Information->VertexMNITal. In this case it will be the same as
the RAS. The Talairach coord is the MNI coord adjusted with Mathew
Brett's algorithm, which is more than just a translation.
doug
On Fri, 30 Mar 2007, roberto toro wrote:
Hi,
I'm trying to figure out how to go from a coordinate in mni305 space
to a vertex index in fsaverage. In the README file that comes with
fsaverage it's stated that surface coordinates are in talairach space,
so they align with the MNI305 volume (and the talairach.xfm is the
identity). But when I select a vertex in fsaverage (using tksurfer) I
have three different coordinates. For example, vertex 62176 gives
1. the actual 3d coordinate of the vertex in the mesh
-2.4876, -5.1338, 10.0494
2. the RAS coordinate
-1.97, -4.48, 10.51
3. the Talairach coordinate (which I suppose are in fact MNI305
coordinates..)
-1.95, -3.85, 9.87
this doesn't seem to be just a translation because when I compare
actual 3d and talairach, the difference between the x coord (for
example) of different vertices is not the same...
how does tksurfer convert to talairach coordinates?
thanks in advance!
roberto
_______________________________________________
Freesurfer mailing list
Freesurfer@nmr.mgh.harvard.edu
https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
--
Douglas N. Greve, Ph.D.
MGH-NMR Center
[EMAIL PROTECTED]
Phone Number: 617-724-2358
Fax: 617-726-7422
In order to help us help you, please follow the steps in:
surfer.nmr.mgh.harvard.edu/fswiki/BugReporting
_______________________________________________
Freesurfer mailing list
Freesurfer@nmr.mgh.harvard.edu
https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
