LEFT The correlation plots for each of the schemes outlines in the table and Aortic Valve based ejection fraction are shown on the left side of the figure. For all schemes, the error in measured EF increases with increasing EF (slope > 1). The table illustrates expected error at tow different ejection fractions. RIGHT: Global volume over time curve for a patient with an EF = 45% is shown. The red, green, blue and orange dots represent phases around the EKG trigger which correspond to Schemes A-D. The mid-ventricular end-systole is denoted by a purple dot. The aortic valve opening and closure are shown by two horizontal black bars. The horizontal blue lines indicate the average phases over which individual slices obtain their local maxima or minima.