Magnetic resonance imaging (MRI) appears to provide at least as much diagnostic information as angiography in the evaluation of acquired and congenital forms of disease of the great arteries. Since it can also be used to assess the tissues adjacent to the great arteries, MRI often provides a distinct diagnostic advantage over angiography. In addition, the recently introduced dynamic MRI techniques may provide valuable information regarding hemodynamic abnormalities associated with diseases of the thoracic aorta and the pulmonary arterial system.