Aortopulmonary window is a communication between the main pulmonary artery and the ascending aorta in the presence of two separate semilunar valves. The combination of an aortopulmonary window with interrupted aortic arch is rare. We discuss the unique case of an extremely premature infant weighing 1.7 kilograms who underwent cardiovascular magnetic resonance imaging as a pre-operative assessment in a high-field open 1.0 Tesla magnetic resonance imaging system as a one-stop investigation before complete repair.