Scan-Based Volume Animation
Driven by Locally Adaptive Articulated Registrations

Taehyun Rhee

Samsung Advanced Institute of Technology
U. Southern California

J.P. Lewis

Ulrich Neumann

Krishna Nayak

Animated MRI from a Living Subject

While MRI scans provide static views of a region of a living person and the famous "visible human" project provided a detailed but static interior view of a cadaver, this new work allows for the first time a view of how the interior body deforms during movement. The new algorithm can reconstruct an animated representation of any areas of a living person. Skeletal joints of the reconstructed representation can be moved with a 3D animation program, and the soft tissues deform interactively and realistically according to the MRI scan data.


This paper describes a complete system to create anatomically accurate example-based volume deformation and animation of articulated body regions, starting from multiple in vivo volume scans of a specific individual. In order to solve the correspondence problem across volume scans, a template volume is registered to each sample. The wide range of pose variations is first approximated by volume blend deformation (VBD), providing proper initialization of the articulated subject in different poses. A novel registration method is presented to efficiently reduce the computation cost while avoiding strong local minima inherent in complex articulated body volume registration. The algorithm highly constrains the degrees of freedom and search space involved in the non-linear optimization, using hierarchical volume structures and locally constrained deformation based on the biharmonic clamped spline. Our registration step establishes a correspondence across scans, allowing a data-driven deformation approach in the volume domain. The results provide an occlusion free person-specific 3D human body model, asymptotically accurate inner tissue deformations, and realistic volume animation of articulated movements driven by standard joint control estimated from the actual skeleton. Our approach also addresses the practical issues arising in using scans from living subjects. The robustness of our algorithms is tested by their applications on the hand, probably the most complex articulated region in the body, and the knee, a frequent subject area for medical imaging due to injuries.


Scan-Based Volume Animation Driven by Locally Adaptive Articulated Registrations
IEEE Transactions on Visualization and Graphics March 2011

(U. Southern California publications version)

(publisher version)