Optimizing right ventricular focused four-chamber views using three-dimensional imaging, a comparative magnetic resonance based study.

Abstract

Obtaining focused right ventricular (RV) apical view remains challenging using conventional two-dimensional (2D) echocardiography. This study main objective was to determine whether measurements from RV focused views derived from three-dimensional (3D) echocardiography (3D-RV-focused) are closely related to measurements from magnetic resonance (CMR). A first cohort of 47 patients underwent 3D echocardiography and CMR imaging within 2h of each other. A second cohort of 25 patients had repeat 3D echocardiography to determine the test-retest characteristics; and evaluate the bias associated with unfocused RV views. Tomographic views were extracted from the 3D dataset: RV focused views were obtained using the maximal RV diameter in the transverse plane, and unfocused views from a smaller transverse diameter enabling visualization of the tricuspid valve opening. Measures derived using the 3D-RV-focused view were strongly associated with CMR measurements. Among functional metrics, the strongest association was between RV fractional area change (RVFAC) and ejection fraction (RVEF) (r = 0.92) while tricuspid annular plane systolic excursion moderately correlated with RVEF (r = 0.47), all p < 0.001. Among RV size measures, the strongest association was found between RV end-systolic area (RVESA) and volume (r = 0.87, p < 0.001). RV unfocused views led on average to 10% underestimation of RVESA. The 3D-RV-focused method had acceptable test-retest characteristics with a coefficient of variation of 10% for RVESA and 11% for RVFAC. Deriving standardized RV focused views using 3D echocardiography strongly relates to CMR-derived measures and may improve reproducibility in RV 2D measurements.