I wish to use the transforms generated by fmriprep to normalise some other images (e.g. PET and ASL)
In the dataset each subject has two sessions. For e.g. session 1 my plan was to:
- Get session 1 PET image coregistered to session 1 anatomical image
- Then use _from-orig_to-T1w_mode-image_xfm.txt to get the PET image aligned with the averaged anatomical image
- Then use _from-T1w_to-MNI152NLin2009cAsym_mode-image_xfm.h5 to move the PET image to MNI space
This is the same as suggested here:
After doing step 1 I would then do:
However this does not seem to be working well, and on further investigation it seems to me as though ‘_from-orig_to-T1w_mode-image_xfm.txt’ is in fact the transform for the averaged_anatomical ->session specific image rather than session specific image ->averaged anatomical?
If this is correct, is there a straighforward way to calculate the inverse transform?