Calculation of Left Ventricular Ejection Fraction of Abnormal Heart in SPECT

A method is presented for calculation of left ventricular ejection fraction from EKG-gated SPECT images. The method is based on analyzing volumes of ellipsoids fitted to points of maximal activity in the ventricular wall for systole and diastole. This approach differs from methods that rely on defining the inner myocardial wall for systole and diastole either automatically or by hand. The proposed method should be applicable to patients with large perfusion defects. Details of the method are shown using gated SPECT studies of two human subjects.