It is done slightly differently in SPM, where there spatial
normalization is done with slightly more than just a 4x4 affine
transformation. If A and B are coregistered (use Check Reg to find
out), then you can then simply estimate spatial normalization parameters
from B (saved in *_sn.mat) and apply them to A. The relative image
orientations should be saved in the headers, and these are taken into
consideration when writing spatially normalised images.
Best regards,
-John
-----Original Message-----
From: SPM (Statistical Parametric Mapping) [mailto:[log in to unmask]]
On Behalf Of Niels Focke
Sent: Monday, February 19, 2007 4:19 PM
To: [log in to unmask]
Subject: [SPM] Concatenate transformation matrices
Hello list
I would like to normalize a parametric map (image A) via a high-res T1
(image B).
Does anyone know a possibility to concatenate two transformation
matrices
in SPM5 (two .mat files) into a single matrix? In this case I would
concatenate the A-to-B.mat file with the B-to-normspace.mat file to give
me a A-to-normspace.mat file. In fsl that job is quite easy (convert_xfm
-concat). Is there any similar function in spm5?
Of course I could reslice image A to the highres image B and then use
the
normalization parameters of image B but this has the disadvantage of
double interpolation. I would like a more straightforward solution.
Any recommendations would be highly appreciated.
________________________________________________________________
Dr. Niels Focke
Research Fellow
UCL-ION Epilepsy Imaging Group
MRI Unit
National Society for Epilepsy
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