Quantitative biplane angiography for right and left ventricular volume determination

Abstract

A computer program is presented, which is suitable for both enddiastolic and endsystolic and semi-automated biplane frame-by-frame volume determination of the right (RV) and left (LV) ventricle. Compared to other programs an important features is presenting the biplane images side by side after optimal pairing. That means the images are rotated in such a way that the epipolar lines in both planes represent the same cross sectional planes. Additionally, the magnifications of the frontal and lateral projection are fitted resulting in identical scales. The paired images are necessary for a reliable assignment of the anatomical structures of the heart to their X-ray projections. Especially in evaluations of the RV this is useful for correctly tracing the pulmonary valve in the frontal projection as this structure is superimposed by the pulmonary artery and parts of the RV. Furthermore the fitting of the magnifications in both projection planes can be used for detecting faulty geometric calibrations, which become obvious, when the corresponding distances in the planes do not agree. As a result of optimal image pairing the mean percent difference of the calibrated vertical extent of the lateral and frontal projection is significantly (p<0.01) reduced as compared to the unpaired biplane ventricular analysis.