> SPM's spatial normalization can generate a *_sn.mat file, describing the
> FORWARD transformation of the source to the target. Could anyone explain
> the content of the mat file and the meaning of each variable in it? We
> would like to further utilize these transformation inforamtion.
The spm_write_sn.m file should give you the information that you need - but
you'll need to be able to read Matlab.
>
> Furthurmore, how to obtain or derive, if possible, an INVERSE transform of
> the FORWARD transform. With this, we could transform the "template" images
> back to our "source" images. This operation has several important
> applications. One example is "partial volume effect" recovery.
Try the Deformations toolbox. For more information, you could take a look at
the VBM Lab from the USA SPM Course
http://www.fil.ion.ucl.ac.uk/spm/course/usa/Labs/Lab_3_VBM.pdf
At the very end, under "Deformations Toolbox", it shows you how to take an
image in MNI space (e.g. an ROI mask image) and transform it back to an
individual's space (this paragraph is courtesy of Tom Nichols).
Best regards,
-John
|