I don't know the answer to this one - which is one of the reasons why I
provided both options. The "preserve concentrations" option keeps the
original intensities in the images, and simply moves them to different
locations. The "preserve total" option scales intensities according to how
much expansion or shrinkage occurs during the spatial normalisation
(analagous to "modulation" in VBM studies).
Best regards,
-John
On Tuesday 18 July 2006 15:48, Anna Caroli wrote:
> Dear SPM users,
> I'm working with SPECT images, and I'm using SPM2.
> Can anybody tell me, in the defaults setting step, if it's better to use
> "preserve total" or "preserve concentration"?
> What's the meaning of preserve total/concentration for a functional
> image?
> Thanks a lot for your help!
> Anna
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