Many cardiovascular diseases are associated with abnormal function of myocardial contractility or dilatability, which is related to elasticity changes of the myocardium over the cardiac cycle. The mouse is a common animal model in studies of the progression of various cardiomyopathies. This article introduces a novel non-invasive approach using microscopic scale magnetic resonance elastography to measure the myocardium stiffness change during the cardiac cycle on a mouse model.
A harmonic mechanical wave of 400 Hz was introduced into the mouse body. An electrocardiograph-gated and respiratory-gated fractional encoding cine-MRE pulse sequence was applied to encode the resulting oscillatory motion on a short-axis slice of the heart. Five healthy mice ages from 3 to 13.5 months were examined. The weighted summation effective stiffness of the left ventricle wall during the cardiac cycle were estimated.