Comparison of semi-automated and manual measurements of left ventricular volume from 3D echocardiographic studies of patients with cardiomyopathy

Manual measurement of left ventricular volume from 3D echocardiographs is time consuming, and there is a clinical need for automatic methods. We describe a semiautomatic method which uses a 3D image gradient operator and a short-axis boundary detector. Six patients with cardiomyopathy were studied using 3D echocardiography and the images were analysed to measure the repeatability of measurement by the semi-automated method, and used to compare measurements of stroke volume and ejection fraction with manual measurements. Within-patient standard deviations of the semi-automated method were 14.6% and 16.4% of the group mean end diastolic and end systolic volumes respectively, and were significantly less than the between-patient standard deviations. No differences between the semi-automated method and the manual method were found for the measurements of ejection fractions or of stroke volumes