Dear David,
> Can anyone tell me why the same PET image, normalized on two separate
> occasions using the same bounding box, produces apparently visually
> identical images that are vastly different in size? Is this a source of
> concern?
>
> Registered Normalized
> Image1: 992k 997k
> Image2: 992k 660k
>
> The image comes from one of 8 scans within a subject who was
> re-registered/normalized when an artifact was detected in one of the scans
> (the image above is not one of the corrupted ones). The analyses are done
> on a PC in Win98.
I guess that this is the second attempt to write the normalised file (SPM
itself rewrites the first image by default!). I further guess that image 1 has
been written with a different bounding box or voxel size initially. You have
then rewritten this file. Unfortunately, if a normalised file exists with the
same name, the file size remains the same, if the new image is smaller. The
solution is to delete the file and use the option "write normalise" again.
-Christian
--
Dr. Christian Buechel
Neurologische Universitaetsklinik, Haus B
Universitaets-Krankenhaus Eppendorf
Martinistr. 52
D-20246 Hamburg
Germany
Tel.: +49-40-42803-4726
Fax.: +49-40-42803-5086
email:[log in to unmask]
www.uke.uni-hamburg.de/kliniken/neurologie/pages/mitarbeiter/buechel_c.htm
www.uke.uni-hamburg.de/kliniken/neurologie/pages/forschung/cnl_index.htm
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