Magnetic resonance imaging (MRI) is an ideal imaging modality for investigating anomalies of the pediatric thoracic aorta. Its multiplanar capabilities allow imaging along anatomic or perpendicular planes, and clearly show the relationship between the great vessels and the airway structures. The most common pediatric aortic lesions investigated by MRI include vascular rings and coarctation of the descending aorta and its surgical complications. Other obstructive, aneurysmal, and positional anomalies of the aorta are readily demonstrated and quantified. However, precise image prescription is necessary to obtain optimal information. This review discusses and illustrates the common pediatric anomalies and current appropriate choices of imaging techniques. © 1993 W.B. Saunders Company. All rights reserved.