Hi All!
Even Jesper made a nice statement to end that interesting discussion, I just would like to throw in one thought to screw up the whole thing. I'm always somewhat worried about one aspect:
If the EPI template is from the old 2T scanner at the FIL, how do I have to take into account the geometrical distortions?
Or, the other way round, the level of geometrical distortions and degree of susceptibility artefacts of EPI images, acquired on a 2T scanner will be different than those from a 1.5T scanner. Correct? And they are also different than those from a 3T or 4T. Correct? And, unfortunately, the whole things depends on my TE time ...
I don't know, how many 2T scanners are out there in the world, but I don't think that these are many. So, in fact, we have some level of misalignment in the data anyway, since my 1.5T or 3T EPI images will never fit into the space, defined by a 2T EPI template ...
So, finally, we should just say it, as Jesper suggested, which is the only correct way and does not make any unrealistic assumptions about the space, in which we are: "...we normalised to the SPM2 EPI-template..."
(By the way, does anyone know the echo time of the sequence, with which the EPI images for the template were acquired?)
Karsten
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Karsten Specht, PhD
Department of Biological and Medical Psychology
& National Competence Centre for functional MRI
University of Bergen
Jonas Lies vei 91
5009 Bergen
Norway
Tel.: +47-555-86279
Fax: +47-555-89872
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http://fmri.uib.no/
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