Optimization of PET-MR registrations for nonhuman primates using mutual information measures: A Multi-Transform Method (MTM)

► A PET-MR registration algorithm is proposed for nonhuman primate brain studies. ► Transforms from our original method often resulted in misaligned PET-MR images. ► The algorithm was tested in 120 datasets, and transforms were assessed visually. ► Successful transforms improved from 78% to 97% with the new registration method.