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.

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Volumetric quantification of RV volume was performed on CMR, CCT, and RT3DE images. Eliminating analysis-related intermodality differences allowed fair comparisons and highlighted the unique limitations of each modality. Understanding these differences promises to aid in the functional assessment of the RV.