No abstract

This is the first study to validate the new 3D-STE technique for LV volume measurements and demonstrate its superior accuracy and reproducibility over previously used 2D-STE technique.

Left ventricular (LV) volumes obtained from RT3DEdatasets are underestimated compared to cardiac magnetic resonance (CMR). We sought to study the accuracy and reproducibility of this technique in a multicenter setting, the inter-institutional differences in these variables in relationship with investigators' experience, and the potential sources of underestimation. 92 patients underwent CMR and RT3DE imaging at 4 different institutions. ESV: r=0.93), but were 29 and 26% lower. This finding was consistent across participating institutions, with the magnitude of bias being related to experience. Exclusion of trabeculae and mitral valve plane from the CMR reference essentially eliminated the inter-modality bias. In conclusion, LV volumes are underestimated in most patients because RT3DE imaging cannot differentiate between the myocardium and trabeculae. IntroductionThe superiority of 3D measurements of LV volume measurements based on endocardial surface detection [1,2] was recently demonstrated for RT3DE imaging in terms of improved accuracy [3,4] and reproducibility of [2,4]. Although this methodology has been compared against CMR in single center studies, it has not been validated in a standardized protocol in a multicenter setting. Importantly, several recent studies have reported that RT3DE underestimates LV volumes [2,5] to a variable extent, but no consensus has been reached regarding the factors contributing towards this error. We hypothesized that this underestimation may be due to differences in spatial and contrast resolution between RT3DE and CMR imaging that determine the level of detail with which the LV endocardial surface is visualized. Also, the inter-modality discordance may be increased by analysis related differences.This study was designed to: (1) validate volumetric analysis of the left ventricle from RT3DE datasets against the standard CMR reference technique in a multicenter setting, (2) compare the reproducibility of this analysis with CMR measurements, (3) study inter-institutional differences in accuracy and reproducibility of the RT3DE volume measurements in relationship with the level of the investigators' experience, and (4) to identify and evaluate the relative contributions of the potential sources of error. Methods Study designInitially, aim 1, i.e. the accuracy of RT3DE volume measurements, was addressed by analyzing RT3DE and CMR images obtained in a large group of patients and comparing ESV and EDV between the two modalities. Aim 2, i.e. the reproducibility of both techniques, was achieved using repeated measurements.To achieve aim 3, i.e. the experience-related interinstitutional differences, investigators in the participating institutions, were given different levels of instruction and training with the prototype software (QLAB, 3DQ-Advanced, Philips). The investigators were not informed that the level of experience was part of the study design. Accuracy and reproducibility were compared between institutions and correlated with the level of experience.To achieve aim 4, i.e. iden...

Compared with CMR reference, 3DE-derived LAV measurements are more accurate than 2DE-based analysis, resulting in fewer patients with undetected atrial enlargement.

No abstract

Background-Left ventricular (LV) mass is an important predictor of morbidity and mortality, especially in patients with systemic hypertension. However, the accuracy of 2D echocardiographic LV mass measurements is limited because acquiring anatomically correct apical views is often difficult. We tested the hypothesis that LV mass could be measured more accurately from real-time 3D (RT3D) data sets, which allow offline selection of nonforeshortened apical views, by comparing 2D and RT3D measurements against cardiac MR (CMR) measurements. Methods and Results-Echocardiographic imaging was performed (Philips 7500) in 21 patients referred for CMR imaging (1.5 T, GE). Apical 2-and 4-chamber views and RT3D data sets were acquired and analyzed by 2 independent observers. The RT3D data sets were used to select nonforeshortened apical 2-and 4-chamber views (3DQ-QLAB, Philips). In both 2D and RT3D images, LV long axis was measured; endocardial and epicardial boundaries were traced, and mass was calculated by use of the biplane method of disks. CMR LV mass values were obtained through standard techniques (MASS Analysis, GE). The RT3D data resulted in significantly larger LV long-axis dimensions and measurements of LV mass that correlated with CMR better (rϭ0.90) than 2D (rϭ0.79). The 2D technique underestimated LV mass (bias, 39%), whereas RT3D measurements showed only minimal bias (3%). The 95% limits of agreement were significantly wider for 2D (52%) than RT3D (28%). Additionally, the RT3D technique reduced the interobserver variability (37% to 7%) and intraobserver variability (19% to 8%). Conclusions-RT3D imaging provides the basis for accurate and reliable measurement of LV mass.

No abstract

No abstract