Dear Randy,
> Was wondering if there are any new methods for converting
> "Talairach" coordinates obtained using spm96 spatial normalization with MNI
> single brain template to the canonical Talairach's atlas coordinates. I used
> the transform from this template to the template from spm95 (PET) that
> Andreas posted but it is not perfect since the template is not matched to
> Talairach. Since the Talairach Daemon contains a scanned version of the
> atlas has anybody warped this to the MNI template?
The page:
http://www.mrc-cbu.cam.ac.uk/Imaging/mnispace.html
has a routine on it which does a reasonable job of MNI to Talairach atlas
conversion.
> Also, what has been the experience of people warping their T2 EPI functional
> data to the spm templates? My success is about 60% with the remainder not
> being close at all. I've taken to warping one subject brain to the template
> and using this as my new template.
Yes, we are having problems too with our 3T EPI data, which have a lot of
susceptibility artefact. Have a look at:
http://www.mrc-cbu.cam.ac.uk/Imaging/fmridefaults.html
In particular we have found it to be important to make sure the images are
reasonably well aligned to the template (in terms of translations and
rotations) before the normalization. This done with the Display button in SPM
- see the Image Orientation section. Also, you may well want to disable the
brain mask - see the Normalisation section and
http://www.mailbase.ac.uk/lists/spm/2000-02/0061.html.
Lastly, as the message notes, you may want to try fewer basis functions - we
got good results from 6 x 7 x 6.
Good luck,
Matthew
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