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 st...

The current protocol for image guidance in open abdominal liver tumor removal surgeries involves a rigid registration between the patient's operating room space and the pre-operative diagnostic image-space. Systematic studies have shown that the liver can deform up to 2 cm during surgeries in a non-rigid fashion thereby compromising the accuracy of these surgical navigation systems. Compensatin...

A hybrid rigid and non-rigid registration algorithm has been presented to register thoracic and abdominal CT images of the same subject scanned at different times. The bony structures are first segmented from two different time CT images, respectively. Then, the segmented bony structures in the two respective images are registered based on their boundary points using a soft correspondence match...

To compensate for soft-tissue deformation during image-guided surgical procedures, non-rigid methods are often used as compensation. However, most of these algorithms first implement a rigid registration to provide an initial alignment. In liver tumor resections, the organ is deformed on a large scale, causing visual shape change on the organ. Unlike neurosurgery, there is no rigid reference av...

Laser range scanners provide rapid and accurate non-contact methods for acquiring three-dimensional surface data, offering many advantages over other techniques currently available during surgery. The range scanner was incorporated into our image-guided surgery system to augment registration and deformation compensation. A rigid body, embedded with infrared diodes, was attached to the scanner f...

In this paper we propose a probabilistic approach to groupwise registration of unstructured high-dimensional point sets. We focus on registration of generalised point sets which encapsulate both the positions of points on surface boundaries and corresponding normal vectors describing local surface geometry. Richer descriptions of shape can be especially valuable in applications involving comple...

3D Rigid intra-operative image registration is an important technique to provide guidance for pre-operative information from different image modalities. Due to the artefacts that cause correspondence ambiguity, accurate registration of US with other image modalities such as computed tomography (CT) is still a challenging problem. We propose a method which considers the registration problem of U...

In this paper, we propose a fast intensity-based registration algorithm for the analysis of contrast-enhanced breast MR images. Motion between pre-contrast and post-contrast images has been modeled by a combination of rigid transformation and free-form deformation. By modeling the conditional probability function to be Gaussian and considering the normalized mutual information (NMI) criterion, ...