Dramatic advances in management of congenital heart disease (CHD) have improved survival todulthood from <10% in the 1960's to nearly 90% in the current era. With this shifting demographic, adult CHD (ACHD) patients now outnumber pediatric CHD patients. ACHD patients demonstrate domain-specific neurocognitive deficits such as impairment in executive function,d with reduced quality of life that includes deficits in educational attainment and. These deficits are related to risk factors that can occur across theuding genetic abnormalities, cumulative hypoxic/ischemic injury, and,dult-onset atherosclerotic cerebrovascular disease. The overarching hypothesis is that ACHDhibit vascular brain injury and structural/physiological brain alterations thatdictive of specific neurocognitive deficits, including executive dysfunction, whichdified by behavioral and environmental enrichment proxies of CR (e.g., level ofducation and lifestyle/social habits). The investigators propose an ancillary study to theHLBI-funded Pediatric Heart Network (PHN) "Multi-Institutional Neurocognitive Discoveryudy (MINDS) in Adult Congenital Heart Disease (ACHD)." The investigators will leverage theDS-ACHD parent study data (i.e., NIH Toolbox neuropsychological battery/clinical data/biological samples) and an established neuroimaging harmonization, which thevestigators currently use for the PHN Single Ventricle Reconstruction (SVRIII) multi-center brain connectome study (R01-HL128818), to measure neuroimaging biomarkers in ACHD patients athe same PHN sites. The specific aims are: Specific Aim #1 (brain injury): To determine if vascular-related brain injury (cortical infarcts, hemosiderin lesions, and white matter hyperintensity) is associated with specific neurocognitive deficits (e.g. NIH Toolbox total) in ACHD patients. Specific Aim #2 (brain structure): To determine if reducedhickness and white matter connectivity are associated with specificurocognitive deficits (e.g. NIH Toolbox frontal executive sub-score) in ACHD patients.Aim #3 (brain physiology): To determine if reduced cerebrovascular reserve (regionalbral blood flow/ resting BOLD imaging) is associated with specific neurocognitive deficits (e.g. NIH Toolbox crystallized composite score) in ACHD patients. Specific Aim #4 (cognitive reserve): To determine if the associations between neuroimaging biomarkers andurocognitive outcomes in ACHD patients are modified by behavioral and environmentalhment proxies of CR, using traditional statistical models and machine learninghniques. Given the paucity of multi-modal neuroimaging studies in ACHD, the proposed studyddresses a major knowledge gap in the ACHD population by providing insight into thehanism underlying impaired neurocognitive outcomes. This study will provideuctural-physiological correlates of neurocognitive outcomes, representing the firstulti-center neuroimaging study to be performed in ACHD. Importantly, other behavioral andvironmental enrichment data will be integrated with these neuroimaging and neurocognitiveutcome data to model cognitive reserve. Results from this research will help shape the careACHD patients, and further our understanding of the interplay between brain injury andgnitive reserve. The proposed ancillary study is thus both feasible and cost-effective byveraging the NHLBI-PHN infrastructure. As such, the proposed research is well aligned withhe NHLBI's Strategic Vision.