3D motion/structure estimation using temporal and stereoscopic point matching in biplane cineangiography

To analyze the 3D motion or the 3D structure of the heart from two sequences of two-dimensional (2D) images, it is necessary to determine the intrinsic and extrinsic parameters of the imaging system. We have presented elsewhere a self-calibration method to determine the absolute geometry of a biplane X-ray imaging system, which is then used to infer the 3D motion/structure. This method does not use a calibration object, it requires only point matches from simultaneous pair of images. However, if the region of interest is relatively small, the number of reference points identified on a simultaneous pair of images is limited. The purpose of this paper is to demonstrate that the stereoscopic point matching can be completed by a temporal point matching to provide the minimal information required for robust 3D motion/structure estimation.