Three-Dimensional Echocardiography: Rational Mode of Component Images for Left Ventricular Volume Quantitation

Abstract

Three-dimensional echocardiography (3DE) improves the accuracy of left ventricle (LV) volumetry compared with the two-dimensional echocardiography (2DE) approach because geometric assumptions in the algorithms may be eliminated. The relationship between accuracy of mode (short- versus long-axis planimetry) and the number of component images versus time required for analysis remains to be determined. Sixteen latex models simulating heterogeneously distorted (aneurysmatic) human LVs (56–303 ml; mean 182 ± 82 ml) were scanned from an ‘apical’ position (simultaneous 2DE and 3DE). For 3DE volumetry, the slice thickness was varied for the short (C-scan) and long axes (B-scan) in 5-mm steps between 1 and 25 mm. The mean differences (true-echocardiographic volumes) were 16.5 ± 44.3 ml in the 2DE approach (95% confidence intervals –27.8 to +60.8) and 0.6 ± 4.0 ml (short axis; 95% confidence intervals –3.4 to +4.6) as well as 2.1 ± 9.9 ml (long axis; 95% confidence intervals –7.8 to +12.0) in the 3DE approach (in both cases, the slice thickness was 1 mm). Above a slice thickness of 15 mm, the 95% confidence intervals increased steeply; in the short versus long axes, these were –6.5 to +8.5 versus –7.0 to +10.6 at 15 mm and –10.1 to +15.7 versus –11.3 to +10.9 at 20 mm. The intra-observer variance differed significantly (p < 0.001) only above 15 mm (short axis). Time required for analysis derived by measuring short-axis slice thicknesses of 1, 15, and 25 mm was 58 ± 16, 7 ± 2 and 3 ± 1 min, respectively. The most rational component image analysis for 3DE volumetry in the in vitro model uses short-axis slices with a thickness of 15 mm.

Live/Real Time Three‐Dimensional Transthoracic Echocardiographic Assessment of Left Ventricular Volumes, Ejection Fraction, and Mass Compared with Magnetic Resonance Imaging

“…RT‐3DTTE improves the accuracy of determining LV volumes and mass compared with 2DTTE because geometric assumptions are eliminated. As a result, these measurements correlate well with those of direct MRI measurements 1–14 . This has proven especially important in clinical population with structurally abnormal hearts 14 .…”

Why Media Matter

“…The basis of comparison in standard telemedicine research, reasonably enough, usually is the diagnosis generated from standard patient-physician encounters, either those involving a single physician or those setting an even higher "gold standard" involving consensus of a team or some other definitive test such as biopsy. And when emerging technologies such as 3D imaging or 3D video are assessed, they often are compared to other more commonly available 2D technologies (cf., Nixdorff et al, 2005;Welch et al, 2005). These comparisons are made to ensure that the technology does not make medical decisions worse.…”

History of echocardiography and its future applications in medicine

“…In the future, a combination of these evolving techniques with 3-dimensional cardiac imaging could potentially create a "virtual heart" display on which regions of interests within the myocardium can be traced with a pointer for guiding precise therapeutic interventions. Such 3-dimensional data sets may be displayed in time and space as dynamic holograms for reducing errors produced by foreshortening and geometric model assumptions inherent in 2-dimensional echocardiography (47)(48)(49).…”