Title
Incorporating rigid structures in non-rigid registration using triangular b-splines
Abstract
For non-rigid registration, the objects in medical images are usually treated as a single deformable body with homogeneous stiffness distribution. However, this assumption is invalid for certain parts of the human body, where bony structures move rigidly, while the others may deform. In this paper, we introduce a novel registration technique that models local rigidity of pre-identified rigid structures as well as global non-rigidity in the transformation field using triangular B-splines. In contrast to the conventional registration method based on tensor-product B-splines, our approach recovers local rigid transformation with fewer degrees of freedom (DOFs), and accurately simulates sharp features (C0 continuity) along the interface between deformable regions and rigid structures, because of the unique advantages offered by triangular B-splines, such as flexible triangular domain, local control and space-varying smoothness modeling. The accurate matching of the source image with the target one is accomplished through the use of a variational framework, in which a composite energy, measuring the image dissimilarity and enforcing local rigidity and global smoothness, is minimized subject to pre-defined point-based constraints. The algorithm is tested on both synthetic and real 2D images for its applicability. The experimental results show that, by accurately modeling sharp features using triangular B-splines, the deformable regions in the vicinity of rigid structures are less constrained by the global smoothness regularization and therefore contribute extra flexibility to the optimization process. Consequently, the registration quality is improved considerably.
Year
DOI
Venue
2005
10.1007/11567646_20
VLSM
Keywords
Field
DocType
conventional registration method,rigid structure,triangular b-splines,non-rigid registration,sharp feature,bony structures move rigidly,local rigid transformation,local control,flexible triangular domain,local rigidity,deformable region,tensor product,human body,degree of freedom
Rigidity (psychology),B-spline,Spline (mathematics),Computer science,Rigid transformation,Regularization (mathematics),Artificial intelligence,Smoothness,Discrete mathematics,Computer vision,Stiffness,Algorithm,Image registration
Conference
Volume
ISSN
ISBN
3752
0302-9743
3-540-29348-5
Citations 
PageRank 
References 
5
0.45
20
Authors
3
Name
Order
Citations
PageRank
Kexiang Wang11036.35
Ying He21264105.35
Hong Qin32120184.31