Atherosclerotic heart disease, a major cause of mortality and morbidity in the United States, has been shown to have its origins in childhood. Deposition of calcium occurring early in the atheromatous process is often observed in postmortem studies of coronary arteries and the aorta. Ultrafast computed tomography (Fast-CT) provides a highly sensitive, non-invasive technique for detecting the presence and quantity of coronary artery calcification (CAC). The 'risk factors' for coronary artery disease have been determined by measuring levels of potential factors in middle-and older-aged adults and determining which predict atherosclerotic cardiovascular disease, including coronary artery disease (CAD), peripheral vascular disease, and cerebrovascular disease. Adult subjects with CAC have a greater number of coronary risk factors, including higher cholesterols. In the age group of 30-39 years, 30 to 40 percent have radiographic evidence of coronary artery or aortic calcification. In the Muscatine Study, the investigators examined coronary risk factors in 2400 subjects during childhood (ages 9-11 years) and again in young adult life (ages 20 to 30 years). This population can now provide important information related to measures of childhood and young adult coronary risk factors predicting the development of the atherosclerotic process in adults in their fourth decade of life.