Hi all,
Two newbie SPM questions:
1) For normalization, do I need to have the entire skull as well as the
brain? While trying to learn SPM, I applied the normalization routine to
the anatomicals as a quick test on a small dataset (I realize this isn't
something you'd normally do). The normalized anatomicals appeared
distorted anywhere where the image was cropped or the skull was missing
(at the top of the image where the skull was out of the coil range; and at
the bottom -- cerebellum and inferior frontal -- where there was full
brain but possibly not enough skull). In those locations, the brain
appeared stretched out to where the skull ought to be. The spatial
normalization output ps image was similarly distorted, but I was told this
is "normal".
2) Do I need to have the functional data include the anterior commissure
to normalize? Our protocol includes both functional slices that cover the
superior part of the brain (sup. parietal and sup. frontal) and anatomical
slices that cover most of the brain. The slices are chosen such that the
functional slices are a subset of the anatomicals (same orientation and
planes) but the anats are thinner and cover a larger extent. Thus I can
select the AC in the anats but not the functionals (planes don't go down
that far). For non-normalized data, I can select a non-AC reference
point (though Glass brains are way off). Is this data SPMable?
Thanks for any tips,
Jody Culham
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