Hello all: After processing cortex reconstruction using Freesurfer, i find that the number of vertices of ?h.sphere.reg for different people is different, How to make sure the point correspondence? the tutorial said that the ?h.sphere.reg file is the results of alignment between subjects and the standard template. If I want to perform hypothesis test for some features on every vertex, How should i do?
thanks
wanlin
Hi Wanlin,
the spherical coordinates of the vertices in the ?h.sphere.reg should be approximately the same for homologous points across subjects. You can use drawn an ROI on one then use mri_label2label to map it to the others for example, or just to see what the alignment is you can use tksurfer->tools->send to subject, which finds the closest point on a 2nd subject to the last clicked point on the first. Then hit "goto saved point" in a second tksurfer and it will show you the corresponding point.
cheers, Bruce
On Fri, 11 Aug 2006, wanlin wrote:
Hello all: After processing cortex reconstruction using Freesurfer, i find that the number of vertices of ?h.sphere.reg for different people is different, How to make sure the point correspondence? the tutorial said that the ?h.sphere.reg file is the results of alignment between subjects and the standard template. If I want to perform hypothesis test for some features on every vertex, How should i do?
thanks
wanlin
Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
The ?h.sphere.reg is a "registration surface". It is sort of like having a registration matrix in that the matrix tells you how to map to a common space but does not actually do the mapping for you. If you want to map surface values (eg, thicknesses) to a common space, then use mri_surf2surf (usually with fsaverage as the target). Alternatively, if you are doing a group analysis, you can use mris_preproc, which will run mri_surf2surf for you.
doug
wanlin wrote:
Hello all: After processing cortex reconstruction using Freesurfer, i find that the number of vertices of ?h.sphere.reg for different people is different, How to make sure the point correspondence? the tutorial said that the ?h.sphere.reg file is the results of alignment between subjects and the standard template. If I want to perform hypothesis test for some features on every vertex, How should i do?
thanks
wanlin
Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
freesurfer@nmr.mgh.harvard.edu
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Bruce Fischl -
Doug Greve -
wanlin