Cardiovascular events are the leading non-cancer cause of mortality after childhood cancer, occurring at a significantly younger age than in the general population. The increased incidence of cardiovascular events adversely impacts the functional capacity, morbidity, and mortality of otherwise relatively healthy 20 to 40 year old individuals. Moreover, understanding of the mechanisms by which cancer treatment could influence the occurrence of latent cardiovascular events is unavailable. Our group and others have established independent, noninvasive magnetic resonance imaging (MRI) measures of cardiovascular risk in middle aged and elderly individuals. Cardiovascular risk include, acute coronary syndromes, cardiac death, and congestive heart failure. The goal of this application is to show that childhood cancer survivors at risk for impaired cardiovascular and cerebrovascular health have increased aortic stiffness, when compared to healthy adolescent and young adult age mate. Studies are designed to determine if MRI measures of cardiovascular function differ between adolescent/adult childhood cancer survivors (n=60), age matched controls (n=30), and adolescents/young adults with planned treatment with chemo- and radiation therapy (n=25). The investigators propose that MRI markers responsible for cardiovascular events represent new clinical indicators that could be targeted to treat asymptomatic cardiovascular diseases.