Magnetic resonance imaging (MRI) is a unique and insightful tool for the as
sessment of physiology and function in congenital heart disease, in both th
e preoperative and postoperative state. MRI can accurately measure the volu
me and mass of unusual ventricular shapes, perform myocardial tissue and bl
ood tagging, and can measure velocity and flow using phase-encoded velocity
mapping. This has added new dimensions to research in pediatric cardiology
. Newer techniques such as oxygen-sensitive MRI and echo-planar MRI promise
further advances in the field. This article describes contemporary MRI stu
dies of the physiology of complex congenital heart disease.