Ulloa JU, Vázquez AÁ, de Vega VM, et al. - In this retrospective study involving patients (n = 18) diagnosed with cardiac/extracardiac shunt, researchers evaluated the intra‐ and interobserver variability of 4D‐flow MRI, and assessed the feasibility of directly measuring the shunt, as well as determined the prognostic correlation with the pulmonary‐to‐systemic (Qp/Qs) flow ratio. Ostium secundum atrial septal defect was the most common shunt type. It was feasible and highly reproducible to measure the Qp/Qs ratio and direct shunt quantification using 4D‐flow MRI. Internal consistency with low intra‐ and interobserver variability was outstanding. The connection between the Qp/Qs ratio, direct flow measurement, mean diameter, and jet area was powerful.