Evaluation of radiocardiographic methods for determination of cardiac output and right and left ventricular ejection fractions using a cardiac phantom

Cardiac output and ejection fractions of the cardiac ventricles are valuable measures of cardiac function. Noninvasive radionuclide techniques for determination of these measures are based on analysis of different data: first passage low frequency, first passage high frequency and multigated equilibrium data. We have evaluated the principles of these methods using a dynamic cardiac phantom. Radiocardiographic determinations of cardiac output and right and left ventricular ejection fractions showed excellent correlation against true phantom values: r = 0.993 (p < 0.001), r — 0.978 (p < 0.01) and r = 0.943 (p < 0.05), respectively. Thus, the findings of the present study demonstrate a high validity of current radiocardiographic measures of cardiac function.