Recent studies indicate that maximizing the mutual information of the joint histogram of two images is an accurate and robust way to rigidly register two mono- or multimodal images. Using mutual information for registration directly in a local manner is often not admissible owing to the weakened statistical power of the local histogram compared to a global one. We propose to use a global joint histogram based on optimized mutual information combined with a local registration measure to enable local elastic registration. Keywords: multimodal elastic registration, matching, mutual information 1. INTRODUCTION Medical imaging has become an increasingly vital component of a large number of clinical applications during the past decades. These applications not only concern diagnostic studies, but also planning, performing, and evaluating radiotherapeutical and surgical procedures. A large number of digital imaging modalities is now being used on a routine basis in normal clinical practice. ..