Normal Variation of T1 Values With Cardiac Magnetic Resonance in Healthy Individuals

T1 mapping with cardiac magnetic resonance (CMR) is a novel non-invasive technique to quantitatively characterize the myocardium. T1 mapping is a surrogate marker of myocardial edema and fibrosis, and has the potential to be implemented in the diagnosis and follow-up of various cardiac diseases. However, there is limited data on the natural variation of T1 mapping in healthy individuals. The study comprises three substudies: 1. Reproducibility: Two identical CMR examinations with T1 mapping will be performed on the same day . 2. Hydration changes: Participants will receive two liters of isotonic saline intravenously between two identical CMR with T1 mapping and echocardiographic examinations. The post-fluid order of CMR and echocardiography will be randomized. 3. Time changes: Participants will undergo CMR with T1 mapping at baseline, at 6-months follow-up, and at 1-year follow-up.