Myocardial Tissue Characterization of Acute Myocarditis in Mice: T1, T2 mapping and Extracellular Volume Fraction at 9.4T

Motivation: Myocarditis causes adverse ventricular remodeling. However, its early diagnosis and intervention measures remain to be explored. Goal(s): Exploring quantitative CMR for monitoring myocarditis developments. Approach: Cardiac T1, T2 and ECV mapping were performed in mice at two timepoints. Then the CMR parameters were compared between the control and myocarditis groups. The CMR results were validated against histology. Results: Early acute phase of myocarditis was characterized by increased T2 and ECV. As time progressed, T2 was reduced to the normal level, while myocarditis native T1 and ECV were much higher than the control. The CMR findings agreed with histology. Impact: Quantitative CMR parameters may serve as reliable indicators for edema, inflammation and fibrosis that are associated with the progression of myocarditis, and can be used for early diagnosis, monitoring and management of myocarditis.