Influence of echocardiographic scan plane location and number on the accuracy of three-dimensional left ventricular volume and shape determination

Quantitative 3-dimensional (3-D) echocardiography provides accurate assessment of left ventricular (LV) volume, shape, and function, but depends on manual endocardial border tracing. This study determined the minimal number of borders that need to be traced to obtain an accurate analysis of not only the volume of the left ventricle but also its shape, using the integrated methods for quantitative 3-D echocardiography developed by our laboratory. Transthoracic 3-D echocardiographic studies were obtained in 9 normal subjects and 6 patients with heart disease by freehand scanning. The LV endocardium was manually traced in 17 ± 5 imaging planes and reconstructed in 3 dimensions. The volume and shape of each reconstruction were compared with values measured from surfaces reconstructed from 8 subsets containing 2 to 7 borders; each subset was acquired from different combinations of spatially distributed parasternal and apical views. Accurate measurements were obtained from data sets having ≥5 borders, regardless of whether the image planes were predominantly apical or parasternal views. In conclusion, the LV border should be traced in ≥5 imaging planes to obtain accurate measurements of volume and shape. The piecewise smooth reconstruction method and freehand scanning using a magnetic field tracing system allow the borders to be acquired from whatever combination of acoustic windows and views provides optimal image quality.