OBJECTIVES: This study was designed to compare three-dimensional echocardiography, two-dimensional echocardiography and cineventriculography for the purpose of measuring left ventricular volume in vitro. BACKGROUND: Three-dimensional echocardiographic systems have been shown to be highly accurate in measuring the volumes of balloon phantoms. However, three-dimensional techniques have not been compared with standard two-dimensional echocardiography in vitro or with cineventriculography, the clinical standard for left ventricular volume measurement. METHODS: Excised porcine hearts were prepared with an internal latex sheath that could be filled and maintained with a known ("true") volume of liquid. Each heart was then imaged by cineventriculography, standard two-dimensional echocardiography and three-dimensional echocardiography. Left ventricular volumes were calculated from 15 hearts at 25 volumes ranging from 50 to 280 ml by the following methods: 1) biplane cineventriculography using the area-length method; 2) two-dimensional echocardiography by the apical biplane method using a summation of discs algorithm in 15 cases and the single-plane, four-chamber method using a summation of discs algorithm in 10 cases; and 3) three-dimensional echocardiography using a polyhedral surface reconstruction volume computation algorithm based on multiple nonparallel, nonevenly spaced short-axis cross sections. RESULTS: Results were compared with true volume, and a nonparametric analysis of variance was performed. Both measurement bias (systematic error) and imprecision (random error) were assessed. All methods tended to underestimate the true volume (two-dimensional echocardiography -6.1 +/- 17.6%, three-dimensional echocardiography -4.7 +/- 5.0% and biplane cineventriculography -3.9 +/- 8.2%), although differences were not significant. Although there was a significant correlation between the magnitude of measurement bias and the size of the volume being measured for two-dimensional echocardiography and cineventriculography, the bias of three-dimensional echocardiography was fairly constant over the range of volumes. When bias was accounted for, two-dimensional echocardiography was significantly less precise than cineventriculography and three-dimensional echocardiography in terms of percent error (15.3 +/- 11.9%, 5.6 +/- 5.7% and 3.9 +/- 3.4%, respectively). CONCLUSIONS: Three-dimensional echocardiography using a polyhedral surface reconstruction algorithm for volume computation provides accuracy comparable to that of biplane cineventriculography in this in vitro model. Standard two-dimensional echocardiographic volume computation is significantly less accurate than the other two methods.
OBJECTIVES: This study was designed to compare three-dimensional echocardiography, two-dimensional echocardiography and cineventriculography for the purpose of measuring left ventricular volume in vitro. BACKGROUND: Three-dimensional echocardiographic systems have been shown to be highly accurate in measuring the volumes of balloon phantoms. However, three-dimensional techniques have not been compared with standard two-dimensional echocardiography in vitro or with cineventriculography, the clinical standard for left ventricular volume measurement. METHODS: Excised porcine hearts were prepared with an internal latex sheath that could be filled and maintained with a known ("true") volume of liquid. Each heart was then imaged by cineventriculography, standard two-dimensional echocardiography and three-dimensional echocardiography. Left ventricular volumes were calculated from 15 hearts at 25 volumes ranging from 50 to 280 ml by the following methods: 1) biplane cineventriculography using the area-length method; 2) two-dimensional echocardiography by the apical biplane method using a summation of discs algorithm in 15 cases and the single-plane, four-chamber method using a summation of discs algorithm in 10 cases; and 3) three-dimensional echocardiography using a polyhedral surface reconstruction volume computation algorithm based on multiple nonparallel, nonevenly spaced short-axis cross sections. RESULTS: Results were compared with true volume, and a nonparametric analysis of variance was performed. Both measurement bias (systematic error) and imprecision (random error) were assessed. All methods tended to underestimate the true volume (two-dimensional echocardiography -6.1 +/- 17.6%, three-dimensional echocardiography -4.7 +/- 5.0% and biplane cineventriculography -3.9 +/- 8.2%), although differences were not significant. Although there was a significant correlation between the magnitude of measurement bias and the size of the volume being measured for two-dimensional echocardiography and cineventriculography, the bias of three-dimensional echocardiography was fairly constant over the range of volumes. When bias was accounted for, two-dimensional echocardiography was significantly less precise than cineventriculography and three-dimensional echocardiography in terms of percent error (15.3 +/- 11.9%, 5.6 +/- 5.7% and 3.9 +/- 3.4%, respectively). CONCLUSIONS: Three-dimensional echocardiography using a polyhedral surface reconstruction algorithm for volume computation provides accuracy comparable to that of biplane cineventriculography in this in vitro model. Standard two-dimensional echocardiographic volume computation is significantly less accurate than the other two methods.
Authors: Michal Hubka; Edward L Bolson; John A McDonald; Roy W Martin; Brad Munt; Florence H Sheehan Journal: Int J Cardiovasc Imaging Date: 2002-04 Impact factor: 2.357