OBJECTIVE: To compare correlation between right ventricular ejection fraction (RVEF) derived from MRI and equilibrium radionuclide angiocardiography (ERNA) depicted from the left anterior oblique (LAO) view and anterior (ANT) view [designated as ERNA (LAO) and ERNA (ANT), respectively].METHODS: Twenty-one patients with cardiac disorders received ERNA and cardiac MRI examination within 2 weeks were enrolled in this study. The region of interest (ROI) in right ventricle was depicted from the LAO and anterior (ANT) views to calculate the ERNA (LAO) and ERNA (ANT). Cardiac MRI was performed as served as reference standard to compare correlation between RVEF derived from MRI and ERNA (LAO)/ERNA (ANT), respectively. The repeatability was evaluated according to the intraclass correlation coefficient (ICC).RESULTS: RVEF obtained through MRI was closely correlated with that obtained through ERNA (LAO) view (r=0.883) and ERNA (ANT) view (r=0.891), respectively. Bland-Altam analysis indicated the RVEF derived from the ERNA (LAO) view was obviously underestimated in patients with right ventricular enlargement. Meanwhile, the RVEF derived from the anterior view was much closer to the RVEF derived from MRI compared with that obtained from the LAO view.CONCLUSIONS: ERNA is effective for the determination of RVEF. LAO is still preferred for the determination of RVEF, but the RVEF may be underestimated in the patients with right ventricular enlargement. Determination of RVEF based on ANT is solely recommended in the determination of RVEF in patients with right ventricular enlargement and serves as a control.