Registration of images with topological change via riemannian embedding

In this paper, we develop a new deformable registration algorithm for images with pathology-induced topological changes. In this algorithm, 3D images are embedded as 4D surfaces in a Riemannian space and the registration is conducted as a surface evolution process. Our algorithm differs from existing methods in the sense that it takes an a-priori estimation of areas with topological change as an additional input and generates dense deformation vector fields which are free of false deformation. In particular, the output of our algorithm is composed of a diffeomorphic deformation field and an intensity displacement which corrects the intensity difference caused by the topological changes. The experiments demonstrate that our proposed algorithm is capable of accurately registering images with considerable topological changes. More importantly, the resulting deformation field is not impacted by topological changes, i.e., there is no false deformation.