Note that FS will "conform" the volume to be coronal with axes aligned with the major scanner axes, so that will undo a lot/all of your rotation
On 12/29/2020 11:37 AM, Fischl, Bruce wrote:
p.s. oh, and the .lta format is ascii so you can just look at it to see if it is vox2vox or ras2ras
-----Original Message----- From: freesurfer-bounces@nmr.mgh.harvard.edu freesurfer-bounces@nmr.mgh.harvard.edu On Behalf Of Tisdall, Dylan Sent: Thursday, December 24, 2020 11:41 AM To: freesurfer@nmr.mgh.harvard.edu Subject: [Freesurfer] talairach.lta coordinate spaces
External Email - Use CautionHi list,
I'm trying to understand whether the talairach.lta transform is from the image-axes RAS to talairach or the scanner-axes RAS to talairach. Basically, if I rotate the imaging FOV and scan the same subject, should I expect that to change talairach.lta or not? My confusion stems from the discrepancy between what the scanner terms RAS coordinates (aligned to the gradient axes) vs. what might be plausibly called RAS in the image coordinates (aligned to the FOV axes).
The underlying goal here is to try to evaluate how gradient-axis-aligned someone's head was when they were loaded in the scanner.
Thanks, Dylan
Dylan Tisdall, PhD Research Assistant Professor Department of Radiology Perelman School of Medicine University of Pennsylvania
Room D406 Richards Medical Labs 3700 Hamilton Walk Philadelphia, PA 19104
Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer