Experimental myocarditis in rat can be detected and monitored by cardiac magnetic resonance imaging performed on a clinical 3.0 T scanner

Methods and results Male Lewis rats (n=11) were subjected to myosin immunization and developed autoimmune myocarditis. Approximately 3 weeks later, rats with myocarditis underwent CMR scan and subsequently, histopathological evaluation. Rats with myocarditis showed pericardial thickening, effusion, and LV wall motion abnormalities with septal hypokinesis. Short axis views showed patchy delayed enhancement of epicardial segments, with distribution mainly located within the inferolateral LV wall including the septum. This increased signal/hyperenhancement defines focal areas of myocardial fibrosis/ edema and/or necrosis, highly suggestive of inflammation. Additionally, the presence of large pericardial effusion provides supportive evidence for the existence of perimyocarditis. Indeed, high correlation was found