@article {1248, title = {A spline-based non-linear diffeomorphism for multimodal prostate registration.}, journal = {MEDICAL IMAGE ANALYSIS}, volume = {16}, year = {2012}, note = {UT: 000309694100015ScopusID: 84866118888doi: 10.1016/j.media.2012.04.006}, month = {Aug 2012}, pages = {1259 - 1279}, type = {Journal article}, abstract = {

This paper presents a novel method for non-rigid registration of transrectal ultrasound and magnetic resonance prostate images based on a non-linear regularized framework of point correspondences obtained from a statistical measure of shape-contexts. The segmented prostate shapes are represented by shape-contexts and the Bhattacharyya distance between the shape representations is used to find the point correspondences between the 2D fixed and moving images. The registration method involves parametric estimation of the non-linear diffeomorphism between the multimodal images and has its basis in solving a set of non-linear equations of thin-plate splines. The solution is obtained as the least-squares solution of an over-determined system of non-linear equations constructed by integrating a set of non-linear functions over the fixed and moving images. However, this may not result in clinically acceptable transformations of the anatomical targets. Therefore, the regularized bending energy of the thin-plate splines along with the localization error of established correspondences should be included in the system of equations. The registration accuracies of the proposed method are evaluated in 20 pairs of prostate mid-gland ultrasound and magnetic resonance images. The results obtained in terms of Dice similarity coefficient show an average of 0.980+/-0.004, average 95\% Hausdorff distance of 1.63+/-0.48mm and mean target registration and target localization errors of 1.60+/-1.17mm and 0.15+/-0.12mm respectively.

}, isbn = {1361-8415}, doi = {10.1016/j.media.2012.04.006}, author = {Jhimli Mitra and Zoltan Kato and Robert Mart{\'\i} and Oliver Arnau and Xavier Llad{\'o} and Desire Sidibe and Soumya Ghose and Joan C Vilanova and Josep Comet and Fabrice Meriaudeau} } @conference {1226, title = {A non-linear diffeomorphic framework for prostate multimodal registration}, booktitle = {International Conference on Digital Image Computing: Techniques and Applications (DICTA)}, year = {2011}, note = {ScopusID: 84856980939doi: 10.1109/DICTA.2011.14}, month = {Dec 2011}, pages = {31 - 36}, publisher = {IEEE}, organization = {IEEE}, type = {Conference paper}, address = {Noosa, QLD }, abstract = {

This paper presents a novel method for non-rigid registration of prostate multimodal images based on a nonlinear framework. The parametric estimation of the non-linear diffeomorphism between the 2D fixed and moving images has its basis in solving a set of non-linear equations of thin-plate splines. The regularized bending energy of the thin-plate splines along with the localization error of established correspondences is jointly minimized with the fixed and transformed image difference, where, the transformed image is represented by the set of non-linear equations defined over the moving image. The traditional thin-plate splines with established correspondences may provide good registration of the anatomical targets inside the prostate but may fail to provide improved contour registration. On the contrary, the proposed framework maintains the accuracy of registration in terms of overlap due to the non-linear thinplate spline functions while also producing smooth deformations of the anatomical structures inside the prostate as a result of established corrspondences. The registration accuracies of the proposed method are evaluated in 20 pairs of prostate midgland ultrasound and magnetic resonance images in terms of Dice similarity coefficient with an average of 0.982 {\textpm} 0.004, average 95\% Hausdorff distance of 1.54 {\textpm} 0.46 mm and mean target registration and target localization errors of 1.90{\textpm}1.27 mm and 0.15 {\textpm} 0.12 mm respectively. {\textcopyright} 2011 IEEE.

}, isbn = {978-1-4577-2006-2 }, doi = {10.1109/DICTA.2011.14}, author = {Jhimli Mitra and Zoltan Kato and Robert Mart{\'\i} and Oliver Arnau and Xavier Llad{\'o} and Soumya Ghose and Joan C Vilanova and Fabrice Meriaudeau} }