Dear Randy: I have had similar experience with using the T2 EPI template.
Two things at least seem to be important. First, when EPI volumes are
located off the center of the field of view (i.e. differently from the
template) the talairaching can go seriously awry. Second, reducing the
number of basis functions often helps to prevent strange warps. The problem
with warping one of your own brains to the template and then using this in
turn as a template is that you may introduce a systematic inaccuracy, which
is then applied to all of your subjects. This is hard to rule out unless
you have very good anatomical information in your EPIs (typically not the
case).
Axel
>Users of spm:
>
>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?
>
>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.
>
>Appreciate any help.
>
>Randy Benson
***************************************
Ralph-Axel Mueller, PhD
Dept. of Cognitive Science
University of California, San Diego
Tel.: (858)-551-7926
Fax: (858)-551-7931
E-mail: [log in to unmask]
Mailing address:
R.-A. Mueller
Children's Hospital Research Center
8110 La Jolla Shores Dr. #200
San Diego, CA 92037
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