When I display my images and the img template in spm2b I notice that the
voxel dimensions are now -2 x 2 x 2. Is this the signature of an inverted
left/right coordinate system?
Stefano Marenco, MD
Senior Staff Fellow
NIMH/CBDB
10 Center Drive, Room 4S235
Bethesda, MD 20892
tel (301) 435-8964
fax (301) 451-4269
-----Original Message-----
From: John Ashburner [mailto:[log in to unmask]]
Sent: Friday, March 28, 2003 9:36 AM
To: [log in to unmask]
Subject: Re: normalization problem SPM2
> I have a problem when I try to normalized my images to my customized
> template that is in analyze format (not *.mnc). I select this template and
> the images of all my patients but this error massage appears:
>
> ??? Error using ==> spm_affreg
> Reference images must all have the same orientation
> Error in ==> C:\MATLABR11\spm2b\spm_normalise.m
> On line 172 ==> [M,scal] = spm_affreg(VG1, VF1, aflags, M,scal);
> Error in ==> C:\MATLABR11\spm2b\spm_normalise_ui.m (run_ui)
> On line 352 ==> spm_normalise(Template, subj(i).P,
> subj(i).matname,... Error in ==> C:\MATLABR11\spm2b\spm_normalise_ui.m
> On line 272 ==> run_ui(defs);
> ??? Error while evaluating uicontrol Callback.
This one happens when all the templates and brain-masks are not all
in exactly the same orientation. I am guessing that the SPM2b
brainmask.mnc file was used with a customised template in Analyze
format. If this is the case, then I think this is what caused the
problem. One of the files uses a left-handed co-ordinate system,
whereas the other one uses a right-handed system.
I could have re-coded SPM2b to allow templates in all kinds of different
orientations, but this would have made things slower, and the code
much more complicated.
Best regards,
-John
--
Dr John Ashburner.
Functional Imaging Lab., 12 Queen Square, London WC1N 3BG, UK.
tel: +44 (0)20 78337491 or +44 (0)20 78373611 x4381
fax: +44 (0)20 78131420 http://www.fil.ion.ucl.ac.uk/~john
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