Effect of background correction on left ventricular ejection fraction calculation through analysis of a simple cardiac model.

The dependence of the left ventricular ejection fraction calculation on the background correction in gated cardiac blood pool studies is examined by analyzing a simple cardiac model. It is shown that the ejection fraction is relatively insensitive to the background correction when an accurately determined variable region of interest is used, but that with a fixed region of interest the background correction must be accurately estimated. A similar ejection fraction-background correction relationship is obtained in the analysis of clinical cardiac data. Based on the cardiac model, two methods are suggested which, with further investigation and refinement, may lead to a more accurate and consistent technique for determining ejection fraction and background.