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

The purpose of the study is to determine the normal variation of T1 values with cardiac magnetic resonance in healthy individuals with respect to reproducibility, changes over time, and dependency on hydration status.

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.