Three-dimensional reconstruction of ventricle from biplane angiocardiograms via equal-divisor surface

Abstract

The measurement of left ventricular function is greatly enhanced when the three-dimensional shape of the ventricle can be closely assessed by biplane angiocardiograms taken from two perpendicular X-ray camera sets. The ventricle shape can be reconstructed by dividing each of the two orthogonal projection images into corresponding slices, processing each pair of corresponding slices to form a binary cross-sectional image, and stacking up these parallel cross-sectional images. Existing methods of reconstructing cross sections often involve assumptions of elliptic shape or convex symmetry. Recently, a new approach was proposed to reconstruct each cross section by estimating an equal-divisor curve instead of estimating the boundary directly. The approach works well as long as a certain regularity condition (a much relaxed assumption) is satisfied. The notion is extended to the equal-divisor surface of a three-dimensional object with two orthogonal projections. A method for the direct three-dimensional reconstruction of the left ventricle (instead of piling up the parallel reconstructed two-dimensional cross sections) is given. >