A comparison of methods for estimating left ventricular volumes from radionuclide ventriculography.

An accurate reproducible measurement of left ventricular volume is important in the evaluation of cardiac disease. Four methods of left ventricular volume measurement by radionuclide ventriculography have been compared and their reproducibility assessed in a patient group. The methods studied were a geometric method, a method based on count data alone and two methods which require a blood sample and an estimate of ventricular depth. The accuracy of absolute volumes is difficult to determine due to the lack of a 'gold standard'. The method using count data alone was found to give reproducible results. Volumes can be calculated quickly and easily from data acquired in a standard radionuclide ventriculogram. End systolic volumes calculated using this method clearly separated normal and abnormal patient groups.