Cardiac MRI findings most associated with myocarditis?

• A. Normal myocardium.
• B. Cardiac MRI showing myocardial edema.
• C. Coronary artery stenosis.
• D. Large pericardial effusion.

Answer: (B)

Myocarditis causes inflammatory injury to the heart muscle, which leads to edema and increased interstitial water. Cardiac MRI is excellent for tissue characterization, so edema appears as high signal on T2-weighted sequences or via T2 mapping. This acute edema is a strong, characteristic indicator of myocarditis and helps distinguish it from ischemic injury due to coronary disease, which tends to produce a different injury pattern tied to coronary territories. Large pericardial effusion can occur but isn’t as specific to myocarditis, and a completely normal myocardium would not show edema. So, myocardial edema on cardiac MRI most closely reflects the acute inflammatory process of myocarditis.