Aortic aneurysm patients benefit from exercise yet patients and physicians do not know a safe level. Cardiac MRI (CMR) is the most comprehensive imaging modality for phenotypic evaluation of patients with cardiac disease but it has not been used to study aneurysm patients. The purpose of this project is use exercise CMR to understand regional aortic function and quantify aortic elasticity in these populations while exercising. This project will correlate the exercise CMR data with the biomechanical properties of the patient's aortic tissue, including epiaortic ultrasound and TEE performed during aortic repair, and explanted aortic specimens subjected to ex vivo uniaxial tensile testing. Correlating this data with aortic response to exercise will allow us to understand how aortic size, in vivo circumferential strain values, ex vivo aortic efficiency and mechanical failure all relate to exercise physiology.