Assessment of left ventricular volumes using densitometry of X-ray films

Left ventricular volume was assessed densitometrically by means of the mean logarithm of grey level (MLG) of a constant region of interest which included the ventricle silhouette. Stroke volume was obtained from MLG different between diastole and systole, without injection of contrast material. The results were significantly lower than those obtained by area-length method. Ejection fraction was derived from MLG difference between two consecutive diastoles after intraventricular injection of contrast material. The results were well correlated with those calculated by the area-length method.<>