Hi Kelli,
2 reasons. One is if you use the talairach to average functional data
for whole-brain analysis. The other is for reporting purposes. We do use
it a bit in the intensity normalization, but if the cortical labels look
fine then it's not a problem.
cheers,
Bruce
On Tue, 2 Jan 2007, Dominick, Kelli, Ray
Carpenter wrote:
Thanks so much for your response. Is it necessary for the talairach
transform to be corrected for the freesurfer cortical and subcortical
segmentation to work properly? Our labels look good. What is the
reason/purpose behind fixing the transform? Looking at the
ReconAllDevTable it doesn't look like the transform is used.
Thanks again for your help,
Kelli
-----Original Message-----
From: Bruce Fischl [mailto:[EMAIL PROTECTED]
Sent: Wednesday, December 27, 2006 7:36 PM
To: Dominick, Kelli, Ray Carpenter
Cc: freesurfer@nmr.mgh.harvard.edu
Subject: Re: [Freesurfer] talairach questions
Hi Kelli,
the official talairach xform is in mri/transforms/talairach.xfm and it
uses the MNI tools to transform into the MNI space. The talairach.lta is
something that is used as part of the subcortical segmentation, and we
believe could work as a tal xform, but we don't use it as such as it
hasn't
been validated to be a true talairach space. We may do some internal
verification one of these days and use it instead, but not yet.
cheers,
Bruce
On Wed, 27 Dec 2006, Dominick, Kelli, Ray Carpenter wrote:
Hi All,
We have had a number of brains with very bad talairach transforms
however aparc+aseg looks fine. In addition, while the talairach.xfm
transform is very bad talairach.Ita is not. Is the bad xfm transform
still a problem even though it is not affecting the labels. And if so
which transform should I attempt to correct in tkregister2 in order to
fix the problem? (I ask because it looks like that some of the
tutorials
still refer to old file names that have changed in the stable
versions).
I am using v3.03.
Thanks in advance for your help!
Kelli
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