The effect of various background protocols on the measurement of left ventricular ejection fraction in equilibrium radionuclide angiography.

Four methods of calculating left ventricular ejection fraction from equilibrium radionuclide angiography have been assessed for inter-observer variability and compared to single-plane contrast cineangiography. The superiority of data-processing methods which use a left ventricular region of interest which follows the changing size of the left ventricle into systole is demonstrated. A simple method of correcting for background is suggested as an alternative for those centres not possessing the necessary software for methods involving a changing region of interest.