Cerebral Anatomy, Hemodynamics and Metabolism

Inclusion Criteria: SV Patients * Subjects ages 3 to 15 years old who have completed their Fontan procedure and their parents/guardians. * Any complex congenital heart lesion that has SV physiology of either right ventricle (RV) or left ventricle (LV) morphology. * Ability to undergo a 60-90 minute MRI scan under general anesthesia or deep sedation if general anesthesia or sedation is needed. * Parents signing informed consent. Healthy Controls * Males and females ages 3 to 15 years old if in the original cohort and if not in the original cohort, age matched with Groups I and II, and their parents/guardians. * Normal cerebral and cardiac anatomy who are normocephalic and who are asymptomatic. * For normal controls being prospectively enrolled and not part of the original grant, the ability to extend the clinical MRI an extra 15-20 minutes. * For normal controls undergoing sedation, the ability to extend anesthesia for approximately 15-30 minutes for research purposes only. * Parents signing informed consent. Volunteers * Patients who come to CHOP for a clinically indicated MRI. * The ability to extend the clinical MRI an extra 15-20 minutes. * If 18 or over, patient signing informed consent. * If under 18, parents signing informed consent. Exclusion Criteria: SV Patients * A patient whose primary language is not English. Patients who speak English who have parents or guardians who do not speak English would not be excluded. * Any condition judged by the patient's physici…