Three-dimensional echocardiographic reconstruction and geometric analysis of the human mitral valve

Abstract

Summary form only given. The authors describe a noninvasive technique for three-dimensional (3-D) reconstruction of the mitral valve from echocardiographic images and algorithms for objective analysis of leaflet-annular relationships. A sonic locating system acquires the transducer orientation in 0.1-s intervals, whereas images and an ECG are recorded during scans of the valve. The system was able to reconstruct objects of known size and shape with derivations of less than 2 mm. Videotaped images at selected points in the cardiac cycle are converted to digital format, and the leaflet surfaces traced with a digitizing tablet. By combining different tomographic views and displaying them on a 3-D interactive graphics system, it is possible to study the shape of the mitral value. To provide quantitative data on the valve geometry, a mapping algorithm has been developed that produces a coherent leaflet surface from the reconstructed traces. Reconstruction of the shape of the mitral valve in 15 normal subjects revealed nonplanarity of the mitral annulus and demonstrated that leaflets can appear to ascend above the mitral annulus in the apical four-chamber view without displacement above the 3-D boundaries of the annulus. >