Monday, November 4, 2002
533

Three-Dimensional and Interactive Animation of Carpal Kinematics: An Example of Real-Time Modeling of Complex and Dynamic Anatomy

Hooman Soltanian, MD, Aaron Oliker, BA, Robert W. Beasley, MD, Cornelia Golimbu, MD, Geoffrey C. Gurtner, and Court B. Cutting, MD.

At present Computerized Tomography (CT) and Magnetic Resonance Imaging (MRI) can provide us with extremely high-resolution images. However, these images continue to be two-dimensional, static, and unable to visualize the dynamic relationship between anatomic structures. Recent advances in animation technology, have greatly enhanced the ability of computer generated animations to simulate real objects and their interactions with a high degree of accuracy. Our goal was to bring together the advancements in these two unrelated fields to produce three-dimensional anatomic models which show the dynamic relation of parts with a clarity previously unknown while enabling us to quantify angular and translation motions with precision. This 3D model would allow the visualization from any viewpoint and also elimination of parts blocking or confusing the images of objects of primary concern. The body's most complex joint, the wrist, was chosen as the first example. We used high-resolution CT images of fresh frozen human specimens. Using a specialized rig, the wrist was scanned in 12 positions. Three-dimensional surface models were created and superimposed. Using the animation software, each bone was animated through its entire motion relying on the CT data. Algorithms were then construed to allow direct and exact measurement of angular and translation changes for each object. The measurements are performed without the need for placement of markers or biomechanical sensors which could interfere with the motion by virtue of their presence. The potentials of the system as a teaching tool are obvious. This system can also be used to plan and simulate complicated surgical procedures. We will also demonstrate how the main portion of the three-dimensional model can be used via the Internet without the need for complicated and expensive equipment.