if you have the voxel index (col, row, slice) then you can:

V2R = [ -1.00000 0.00000 0.00000 128.00000 0.00000 0.00000 1.00000 -128.00000 0.00000 -1.00000 0.00000 128.00000 0.00000 0.00000 0.00000 1.00000 ]

crs = [col row slice]';

xyz = V2R[crs+1; 1];

then find the vertex whose xyz coors are closest to xyz

Yunjie Tong wrote:

Hi freesurfer experts,

I have a single subject anatomical data in freesurfer. If I know the volume index of a point on the surface of the cortex ( from T1.mgz in TkMedit), how can I find out the corresponding vertex index or the vertex RAS in TkSurfer. Thanks. BTW, I am using matlab.

Thanks,

Yunjie _______________________________________________ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer

Hi Yunjie,

check out:

http://surfer.nmr.mgh.harvard.edu/fswiki/CoordinateSystems?action=AttachFile...

there is also more coordinate system info on the wiki that should let you know what you need.

cheers, Bruce

On Fri, 19 Dec 2008, Yunjie Tong wrote:

Hi freesurfer experts,

I have a single subject anatomical data in freesurfer. If I know the volume index of a point on the surface of the cortex ( from T1.mgz in TkMedit), how can I find out the corresponding vertex index or the vertex RAS in TkSurfer. Thanks. BTW, I am using matlab.

Thanks,

Yunjie _______________________________________________ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer