Motion Extraction for Left- Ventricular Volume Measurement

Methods to automatically determine the boundary of left heart chambers from X-ray films (cineangiocardiograms) by computer are discussed. Several authors have considered entering a first approximation to the boundary manually by light-pen, and then letting the computer determine the exact boundary from successive frames automatically. A method to do the first step automatically as well is proposed in this paper, utilizing ventricle motion and contrast medium flow. Experiments indicate that brightness as a function of time varies much stronger inside the area of the left heart chamber than outside, due to heart, contraction and contrast medium fluctuation. Hence, using a suitable criterion for motion, it is possible to extract an approximate outline of the left ventricle by simple operations. This outline is then used as initial information for the subsequent frame-by-frame detection of the precise boundary of the heart chamber.