Estimation of the right ventricular volume and ejection fraction by transthoracic three-dimensional echocardiography - A validation study using magnetic resonance imaging

Aims. To validate the use of three-dimensional transthoracic echocardiograp hy compared with the magnetic resonance imaging for determination of right ventricular volume and ejection fraction. Methods and results: We recorded transthoracic echocardiographic images starting from the apical four-chambe r view in which the RV is clearly visualized in 15 healthy volunteers. The scanning plane of the RV was obtained by the rotational scanning technique in 2 degree angular increments for three-dimensional reconstruction. The RV volumes in end-diastole and end-systole were calculated using a Tomtec thr ee-dimensional reconstruction computer. We also assessed the RV by cine mag netic resonance imaging using the Siemens Magnetom Impact Expert (1.0 T). C ine gradient echo images were obtained in the short axis of the RV. The RV volume at each phase was calculated by Simpson's method. We also calculated the RV ejection fraction. The RV volumes in end-diastole and end-systole w ere 111+/-22 ml and 52+/-13 ml, respectively as determined by three-dimensi onal echo, and 115+/-18 ml and 55+/-14 ml determined by MRI. The right vent ricular volumes at end-diastole and end-systole determined by three-dimensi onal echo were correlated with the volumes determined by MRI (r=0.94 and 0. 97, respectively, p<0.001). The RV ejection fraction determined by three di mensional echo was also correlated with the ejection fraction determined by MRI (r=0.90, p<0.01). Conclusions. Three-dimensional transthoracic echocar diography provided reliable calculations of the right ventricular volume an d ejection fraction.