Cardiac MRI Diagnosis of Large Aortopulmonary Collateral and Pulmonary Sequestration Presenting as Left Chamber Dilation

While an echocardiogram is usually sufficient to determine the etiology of left ventricular and aortic dilation in pediatric patients, cross-sectional imaging may complement echocardiography when the diagnosis is unclear. We present the case of a two-year-old child with left atrial, left ventricular, and aortic dilation caused by an intralobar pulmonary sequestration with a large distal aortopulmonary collateral requiring cardiac magnetic resonance imaging (MRI) for diagnosis. Cardiac MRI has the unique ability to provide cross-sectional anatomic information, in addition to volumetric and flow data, making it a valuable modality for the diagnostic evaluation of idiopathic chamber or vessel dilation.