Left ventricular volume determination by 3-D echocardiographic volume imaging and biplane angiography
Diabetes Mellitus, Type 2
Hypertrophy, Left Ventricular
Objectives. This study was undertaken to compare, in vitro, the accuracy of 3-D echocardiographic imaging to contrast ventriculography for the estimation of left ventricular volumes. Background. Compared to angiography and 2-D echocardiography, 3-D echocardiography avoids use of geometric assumptions and may improve evaluation of chamber size and shape of irregular cavities. We previously demonstrated that our 3-D echocardiographic system accurately estimated the volume of variably shaped balloons. Methods. Left ventricular cast volumes from 6 excised formalin fixed sheep hearts filled with a solution of agarose and angiographic contrast agent were measured by water displacement. From the 3-D echocardiographic reconstructions, adjacent short axis slices were derived and the endocardial borders were manually traced; the volumes of individual slices of each ventricle were summed as the cavity volume. Angiographic left ventricular volumes were calculated by Chapman's method from 30°right anterior oblique and 60°left anterior oblique projections. Results. Left ventricular volumes from 3-D echocardiographic reconstructions agreed well with actual volumes, without significant over and underestimation. Left ventricular biplane angiography modestly but systematically underestimated actual volumes. Conclusions. 3-D echocardiographic volume imaging combines excellent measurements of left ventricular volumes from computed reconstruction of tomographic slices with the full spatial resolution of the original 2-D images. In this in vitro model, 3-D echocardiography was more accurate than angiography.