High speed dynamic 3-D surface imaging via stereotactic radiography

Conventional medical imaging modalities are incapable of imaging objects moving at the speeds of opening and closing heart valves. Such an imaging system would require an acquisition time of 1 msec or less to eliminate image distortion. A novel imaging system which couples an electronically gated CCD (charge coupled device) camera and an XRII (X-ray image intensifier) is used to image the motion of small lead markers on the surface of aortic valve cusps. Two independent (non-coplanar) views are acquired and used to reconstruct the 3-D position of the markers throughout the cardiac cycle. The surface geometry is then reconstructed into a tensor product surface by fitting B-spline meshes to the lead marker positions. The aim of this study is to obtain 3-D geometric information which describes the deformations experienced by the aortic cusp throughout the cardiac cycle.