hi folks,
i'm using mri_vol2surf to map functional time series into fsaverage3/4. my assumption is that each vertex time series will be the mean over an icosahedral patch corresponding to the vertex on fsaverage. is that how the resampling is done? also is the resampling done with a single interpolation?
if it's a single step, is there a way to project the interpolation kernel corresponding to a vertex in fsaverage3 on the subject's own surface?
cheers,
satra
On 10/08/2013 09:17 AM, Satrajit Ghosh wrote:
hi folks,
i'm using mri_vol2surf to map functional time series into fsaverage3/4. my assumption is that each vertex time series will be the mean over an icosahedral patch corresponding to the vertex on fsaverage. is that how the resampling is done? also is the resampling done with a single interpolation?
If you spec fsaverageX as the target subject, then it first samples to the individual subject then runs surf2surf to map to fsaverageX. First, for each vertex on fsavergeX it looks for the nearest neighbor in the individual. If fsaverageX is much sparser than the individual, then this will leave a bunch of vertices unused in the individual. So it goes through a second step where it maps all the unused vertices in the individual to the closest vertex in fsaverageX. If a vertex in fsaverageX has multiple vertices from the individual, then the final value is the mean of the individual vertices (unless mapping volume or areal quantities in which case it gets the sum). You can control these options if you first map to the individual using vol2surf then use surf2surf to map from individual to fsaverageX. doug
if it's a single step, is there a way to project the interpolation kernel corresponding to a vertex in fsaverage3 on the subject's own surface?
cheers,
satra
Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
thanks very much doug.
cheers,
satra
On Tue, Oct 8, 2013 at 11:55 AM, Douglas N Greve greve@nmr.mgh.harvard.eduwrote:
On 10/08/2013 09:17 AM, Satrajit Ghosh wrote:
hi folks,
i'm using mri_vol2surf to map functional time series into fsaverage3/4. my assumption is that each vertex time series will be the mean over an icosahedral patch corresponding to the vertex on fsaverage. is that how the resampling is done? also is the resampling done with a single interpolation?
If you spec fsaverageX as the target subject, then it first samples to the individual subject then runs surf2surf to map to fsaverageX. First, for each vertex on fsavergeX it looks for the nearest neighbor in the individual. If fsaverageX is much sparser than the individual, then this will leave a bunch of vertices unused in the individual. So it goes through a second step where it maps all the unused vertices in the individual to the closest vertex in fsaverageX. If a vertex in fsaverageX has multiple vertices from the individual, then the final value is the mean of the individual vertices (unless mapping volume or areal quantities in which case it gets the sum). You can control these options if you first map to the individual using vol2surf then use surf2surf to map from individual to fsaverageX. doug
if it's a single step, is there a way to project the interpolation kernel corresponding to a vertex in fsaverage3 on the subject's own surface?
cheers,
satra
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 greve@nmr.mgh.harvard.edu Phone Number: 617-724-2358 Fax: 617-726-7422
Bugs: surfer.nmr.mgh.harvard.edu/fswiki/BugReporting FileDrop: https://gate.nmr.mgh.harvard.edu/filedrop2 www.nmr.mgh.harvard.edu/facility/filedrop/index.html Outgoing: ftp://surfer.nmr.mgh.harvard.edu/transfer/outgoing/flat/greve/
Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
The information in this e-mail is intended only for the person to whom it is addressed. If you believe this e-mail was sent to you in error and the e-mail contains patient information, please contact the Partners Compliance HelpLine at http://www.partners.org/complianceline . If the e-mail was sent to you in error but does not contain patient information, please contact the sender and properly dispose of the e-mail.
freesurfer@nmr.mgh.harvard.edu
-
Douglas N Greve -
Satrajit Ghosh