Ishizu T, et al. - The study was performed with the goals to confirm the reliability and feasibility of a three-dimensional (3D) speckle-tracking echocardiography (STE) system, using comparison with cardiac magnetic resonance imaging (CMR), and to assess the contribution of regional right ventricular (RV) function to global function. As per findings, 3D STE and CMR measurements were comparable regarding RV volume and RV ejection fraction [RVEF]. Regional RV wall motion indicated that heterogeneous segmental deformations affect global RV function differently. Especially, inlet area strain and outflow circumferential strain seemed relevant factors associated with RVEF in patients with underlying heart diseases.