Dear Chris,
My previous email from 04/19 was in regards to multi-subject SPECT studies.
You seem to be interested in only examining one subject. If you are indeed
looking at only a single subject, it is not necessary to spatially
normalize. However, if you still wish to be able to provide talairach
coordinates in standardized space, then you would likely have to do it the
same way as always. That is, spatially normalize the structural image from
your patient to the template, and apply the transforms to your functional
data. Alternatively, later versions of SPM have an EPI template that can be
used to normalize functional EPI images.
Spatial normalization of lesioned data is tricky. I would be interested in
hearing how it comes out for you.
Regards,
James Patterson
-----Original Message-----
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Sent: 11/18/00 7:55 AM
hi SPM
we would like to scan a patient with a large posterior brain lesion
using fMRI
time-series. Looking at old correspondence from the list about this
issue I have
found a number of relevant mails, but I have some more specific
questions relating to the normalization process and the template to
be used.
James Patterson's mail of 19/4/2000
http://www.mailbase.ac.uk/lists/spm/2000-04/0131.html
suggests that you could use the mean image of all the patients
scanned as a template. My question is this: if you have a single
subject, could
you use the mean image from all the realigned scans of that subject?
What would you gain by this? Clearly this
would not help you put the brain in a Talairach space. On a more
general note, in a situation such as this what would be lost by NOT
normalizing at all - is it likely that your activations would be
spatially displaced? Is there another way to avoid this?
thanks -
Chris Summerfield
departament psiquiatria i psicobiologia clinica
universitat de barcelona
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