Deformation estimation with automatic sliding boundary computation

Abstract

We present a novel method for image registration via a piecewise diffeomorphic deformation which accommodates sliding motion,such as that encountered at organ boundaries. Our method jointly computes the deformation as well as a coherent sliding boundary,represented by a segmentation of the domain into regions of smooth motion. Discontinuities are allowed only at the boundaries of these regions,while invertibility of the total deformation is enforced by disallowing separation or overlap between regions. Optimization alternates between discrete segmentation estimation and continuous deformation estimation. We demonstrate our method on chest 4DCT data showing sliding motion of the lungs against the thoracic cage during breathing.