Evaluation and comparison of surface and intensity based rigid registration methods for thorax and cardiac MR and PET images

In this paper an evaluation and a comparison of surface and image intensity based (mutual information, normalized mutual information and correlation ratio) rigid registration methods for cardiac magnetic resonance and positron emission tomography images are presented. In both types of rigid image registration methods, PET transmission image was used as a linking mediator to register corresponding PET emission image to MR image coordinates. Also direct rigid registration of PET emission image to MR image coordinates was tested. Methods were evaluated with simulated and ten patient MR-PET images and with three optimization methods. Results indicated that NMI and CR methods with simplex optimization provided the most robust and accurate results.