Temporal groupwise registration for motion modeling.

We propose a novel method for the registration of time-resolved image sequences, called Spatio-Temporal groupwise non-rigid Registration using free-form deforMations (STORM). It is a groupwise registration method, with a group of images being considered simultaneously, in order to prevent bias introduction. This is different from pairwise registration methods where only two images are registered to each other. Furthermore, STORM is a spatio-temporal registration method, where both, the spatial and the temporal information are utilized during the registration. This ensures the smoothness and consistency of the resulting deformation fields, which is especially important for motion modeling on medical data. Moreover, popular free-form deformations are applied to model the non-rigid motion. Experiments are conducted on both synthetic and medical images. Results show the good performance and the robustness of the proposed approach with respect to outliers and imaging artifacts, and moreover, its ability to correct for larger deformation in comparison to standard pairwise techniques.