Additional Study Information: Patients with hypoplastic left heart syndrome and other single right ventricle lesions who have undergone the Fontan procedure have a high risk of neurodevelopmental disorders that affect quality of life and adulthood employment. This study will leverage the ongoing National Heart, Lung, and Blood Institute (NHLBI)-funded Single Ventricle Reconstruction Study by using innovative graph measures of brain connectivity to elucidate how alterations of the "connectome" in children with critical congenital heart disease are associated with developmental disabilities and their associated clinical risk factors. Improved understanding of these interrelationships may facilitate development of targeted interventions to improve outcome in the soaring population of adult Fontan survivors.The purpose of this research study is to look at the relationship between the brain structures and long term development in children who have been diagnosed with Congenital Heart Disease (CHD). We want to study the correlation of these brain imaging findings with long term developmental testing in patients born with CHD and compare those with patients who were born healthy and have not been diagnosed with CHD. Participation involves MRI scan of the brain and neurodevelopmental testing. Patients will be compensated $100. Parents will also be compensated for travel and parking expenses.