Ziad,
This probably isn't directly relevant to this task, but if you are working on SPM-AFNI integration, one important thing to note about SPM volumes is that if it has a center specified in the .hdr like this:
SPM originator decodes to 79 113 51
... SPM considers the first voxel to be 1,1,1 -- not 0,0,0, so in AFNI the origin would be 78 112 50.
Also, with spm99 and previous, spatially normalized volumes could be presumed to be what AFNI calls LPI orientation, but not so in spm2:
[
www.fil.ion.ucl.ac.uk]
You probably already knew this, but in case not....
Donna Hanlon