Cognitive impairment, especially short-term memory, [is] prevalent in adolescents with single ventricle congenital heart disease (CHD), [which] can deleteriously impact one's ability for self-care. To date, no research team has reported a link between memory loss and brain structural changes in this high risk, vulnerable population. Therefore, the specific aims for this study are to: 1) Compare brain [structural integrity] of regions which control memory (hippocampus, mammillary bodies [controlling for global cerebral volume and with other relevant cofactors]) between CHD adolescents and age- and gender-matched healthy controls, and 2) Examine the relationship between clinical/questionnaire measures of memory and [volumes of] brain structure[s that control memory function] [ controlling for global cerebral volume] in adolescents with single ventricle CHD and healthy controls. Using a comparative [research] design, 20 single ventricle CHD subjects and 40 age- and gender-matched healthy controls will undergo [high-resolution T1-weighted] structural brain [magnetic resonance imaging] and have memory testing using the Montreal Assessment of Cognition (MoCA) and the Wide Range Assessment of Memory and Learning (WRAML2). Inclusion criteria [for CHD] will be subjects between the ages of 14 to [18] years, single ventricl heart disease, and have undergone Fontan surgical completion, [and for controls will be age (+1 year) and gender-matched to CHD subjects and without any condition that may affect the brain.] [Magnetic resonance imaging] analysis will consist of volumetric measures of [bilateral] hippocampus and mammillary bodies of each subject. Statistical tests will consist of Spearman's Rho and [MANCOVA with age, gender, and global cerebral volume] as covariates with significance set at p < 0.05. In summary, the overall purpose of the study is to identify the association between memory and structural brain injury in adolescents with CHD after staged surgical palliation. [The proposed study] has the potential to dramatically impact clinical practic, as information from this study can guide clinicians toward improved patient education/self-management strategies and assist researchers in the identification and testing of innovative interventions to improve memory and self-care in this growing [patient] population of single ventricle CHD survivors.