Nonrigid Registration of Medical Images: Theory, Methods, and Applications [Applications Corner]

Medical image registration plays an increasingly important role in many clinical applications, including the detection and diagnosis of diseases, planning of therapy, guidance of interventions, and the follow-up and monitoring of patients. The primary goal of image registration is to find corresponding anatomical or functional locations in two or more images. This has many applications: registration can be applied to images from the same subject acquired by different imaging modalities (multimodal image registration) or at different time points (serial image registration). In this article, we will illustrate some of the advances that have been made over recent decades. We will discuss some of the theoretical aspects of nonrigid registration and describe methods for their implementation. Finally, we will illustrate how common problems in medical imaging, such as motion correction and image segmentation, can be solved using image registration.