Daniel
Thank you for the message and the reply. I am now trying to connect Peter's response and yours.
After using @autotlrc I understand from your message that I can use 3dWarp or 3dAllineate to apply the tranformation to other datasets. If I want to apply the transformation to a segmentation (such as Freesurfers aseg.mgz) should I use adwarp as Peter suggested? (adwarp -apar anat+acpc -dpar aseg.nii -prefix aseg_acpc -resam NN)
Perhaps it is 3 different ways to get to the same result. if so, is one better/preferred?
Thanks again for your assitance. I greatly appreciate it.
Tracy