Publications

2012

2011

Ou, Yangming, Aristeidis Sotiras, Nikos Paragios, and Christos Davatzikos. (2011) 2011. “DRAMMS: Deformable Registration via Attribute Matching and Mutual-Saliency Weighting”. Med Image Anal 15 (4): 622-39. https://doi.org/10.1016/j.media.2010.07.002.
A general-purpose deformable registration algorithm referred to as "DRAMMS" is presented in this paper. DRAMMS bridges the gap between the traditional voxel-wise methods and landmark/feature-based methods with primarily two contributions. First, DRAMMS renders each voxel relatively distinctively identifiable by a rich set of attributes, therefore largely reducing matching ambiguities. In particular, a set of multi-scale and multi-orientation Gabor attributes are extracted and the optimal components are selected, so that they form a highly distinctive morphological signature reflecting the anatomical and geometric context around each voxel. Moreover, the way in which the optimal Gabor attributes are constructed is independent of the underlying image modalities or contents, which renders DRAMMS generally applicable to diverse registration tasks. A second contribution of DRAMMS is that it modulates the registration by assigning higher weights to those voxels having higher ability to establish unique (hence reliable) correspondences across images, therefore reducing the negative impact of those regions that are less capable of finding correspondences (such as outlier regions). A continuously-valued weighting function named "mutual-saliency" is developed to reflect the matching uniqueness between a pair of voxels implied by the tentative transformation. As a result, voxels do not contribute equally as in most voxel-wise methods, nor in isolation as in landmark/feature-based methods. Instead, they contribute according to the continuously-valued mutual-saliency map, which dynamically evolves during the registration process. Experiments in simulated images, inter-subject images, single-/multi-modality images, from brain, heart, and prostate have demonstrated the general applicability and the accuracy of DRAMMS.

2010

Sotiras, Aristeidis, Yangming Ou, Ben Glocker, Christos Davatzikos, and Nikos Paragios. (2010) 2010. “Simultaneous Geometric--Iconic Registration”. Med Image Comput Comput Assist Interv 13 (Pt 2): 676-83. https://doi.org/10.1007/978-3-642-15745-5_83.
In this paper, we introduce a novel approach to bridge the gap between the landmark-based and the iconic-based voxel-wise registration methods. The registration problem is formulated with the use of Markov Random Field theory resulting in a discrete objective function consisting of thee parts. The first part of the energy accounts for the iconic-based volumetric registration problem while the second one for establishing geometrically meaningful correspondences by optimizing over a set of automatically generated mutually salient candidate pairs of points. The last part of the energy penalizes locally the difference between the dense deformation field due to the iconic-based registration and the implied displacements due to the obtained correspondences. Promising results in real MR brain data demonstrate the potentials of our approach.
Sotiras, Aristeidis, Yangming Ou, Ben Glocker, Christos Davatzikos, and Nikos Paragios. 2010. “Simultaneous Geometric-Iconic Registration”. In International Conference on Medical Image Computing and Computer-Assisted Intervention, 676–683. Springer, Berlin, Heidelberg.