Hi Doug,
I am using the registration for subjects with ECoG electrodes. I have the electrode locations in RAS coordinates. I convert the RAS coordinates to talairach coordinates using the mri.nii and talairach.xfm files. I realize that talairach coordinates has some limitations, but I am just looking for ballpark estimates of the electrode locations (gyrus, broadman area). In this context do you think the registration is good enough?
Sujith
On Thu, Dec 19, 2013 at 11:19 AM, Douglas N Greve <greve@nmr.mgh.harvard.edu
wrote:
It kind of depends on what is going to happen next. The talairach transform is only used in a couple of contexts: to compute the estimated intracranial volume and when doing volume-based analysis of subcortical structures in FS-FAST. It would also be used if you report tal coordinates for the individual (unlikely) or if you create a group average subject (also unlikely). If none of those apply to you, then I would leave it the way it is. If those do apply, then I would improve it.
doug
On 12/19/2013 10:58 AM, sujith vijayan wrote:
Hi Bruce,
Thanks! I looked at the other slices and they look similar to the screenshot I sent you; to my untrained eyes they look like they could use a slight rotation and shift. I am assuming that means it is a reasonable registration.
However, I am not sure how much a talairach registration needs to be "off" before I need to fix it. The examples at https://surfer.nmr.mgh.harvard.edu/fswiki/FsTutorial/Talairach_freeviewclear... need fixing. Are there any examples somewhere that show more marginal cases?
Sujith
On Wed, Dec 18, 2013 at 10:21 PM, Bruce Fischl <fischl@nmr.mgh.harvard.edu mailto:fischl@nmr.mgh.harvard.edu> wrote:
It looks reasonable to me, although you can't tell for sure from just one slice Bruce On Dec 18, 2013, at 5:38 PM, sujith vijayan <svijayan9@gmail.com <mailto:svijayan9@gmail.com>> wrote:Hi All, I am wondering whether the talairach registration for one of my subjects needs to be fixed. It looks a little off to me, but I am not sure from reading the instructions onhttps://surfer.nmr.mgh.harvard.edu/fswiki/FsTutorial/Talairach_freeview
whether the degree of difference I am seeing is to be expected or not. I've attached a screen shot. Thanks, Sujith <Screen Shot 2013-12-18 at 5.31.00 PM.png> _______________________________________________ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu <mailto:Freesurfer@nmr.mgh.harvard.edu> https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurferThe 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.
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