Real-Time 3D Echocardiographic Quantification of Left Ventricular Volumes: Multicenter Study for Validation with Magnetic Resonance Imaging

Left ventricular (LV) volumes obtained from RT3DE datasets 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. End-systolic and end-diastolic LV volumes correlated highly with CMR values (EDV: r=0.91; 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.