Impact of on-line endocardial border detection on determination of left ventricular volume and ejection fraction by transthoracic 3-dimensional echocardiography

This study was performed to determine whether use of on-line automated border detection (ARD) could reduce data analysis time for 3-dimensional echocardiography (3DE) while maintaining accuracy of 3DE in measures of left ventricular (LV) volumes and ejection fraction (EF). The study proceeded in 2 phases. In the validation phase, 20 subjects were examined with the use of 3DE and of monoplane 2-dimensional (2D) ARD. Results were compared with the reference standard of magnetic resonance Imaging (MRI). In the test phase, 20 subjects underwent two 3DE studies (once with images optimized for visual border definition and once with images optimized for ARD border tracking) and al conventionally used 2D ARD study. For 3DE, volumes and EF were determined with the use of manually traced borders and ARD. Analysis times were recorded with a digital stopwatch. In the validation phase, 3DE and MRI results correlated very well (r = 0.93) without systematic differences. Comparison of 2D ARD with MRI showed good correlation for LV volumes (r greater than or equal to 0.90) and EF (r = 0.85) despite significant underestimation For the test phase, Acoustic Quantification-optimized 3-dimensional datasets underestimated end-diastolic volume and EF relative to visually optimized 3-dimensional datasets regardless of whether borders were hand-traced or ARD was used. However, correlations ranged from r = 0.96 to r = 0.98 for LV volumes and 0.88 to 0.91 for LV EF and were superior to those for 2D ARD. Data analysis times decreased moderately with the use of ARD, but scan times increased; total study times were unchanged. Use of on-line ARD with 3DE reduces data analysis time and is more accurate than conventional monoplane 2D ARD but results in underestimation of LV volumes and EE Additional automated postprocessing techniques may be required to obtain accurate measures, consistently using 3DE in conjunction with on-line ABD.