Estimation of Internal Body Deformations Using an Elastic Registration Technique

This paper describes results of an investigation into the internal body deformation estimation using an elastic registration technique. This registration method uses data intensity values to guide deformations, with local constraints imposed by interaction of sparsely distributed particles. The algorithm is fast, robust and offers high registration accuracy. It enables to include complex constrains on the allowable deformations, which among others permits an accurate representation of rigid structures. The main focus of the paper is put on the quantitative evaluation of the accuracy of the displacement field estimation for non-rigid internal body deformations. The evaluation methodology is described and a number of techniques are used to represent the obtained results. The performed tests have used real as well simulated deformations and real dynamic MRI data.