Figure 1

Myocardial perfusion studies using dynamic contrast-enhanced magnetic resonance imaging (DCE MRI) could provide valuable, quantitative information regarding heart physiology in diseases that lead to diffuse myocardial damage. The use of first-pass contrast-enhanced MRI to identify myocardial perfusion deficits at rest or under stress has shown prognostic value in detecting significant coronary occlusive disease, assessing the risk of cardiovascular events, and identifying the presence of hibernating myocardium post infarct. Normally perfused tissues have enhanced T1-weighted MR signal following intravenous administration of gadolinium, while areas with perfusion deficit remain dark.

A range of semi-quantitative parameters can be gained from the perfusion images. These include: peak myocardial enhancement, time to peak enhancement, contrast enhancement ratio, and the upslope of the signal intensity curve, which may be used to calculate a flow reserve index.

Perfusion images may reveal vascular changes or the existence of diffuse fibrosis in the myocardium. Myocardial perfusion CMRI studies have provided insights into the pathophysiology of epicardial coronary artery disease, microvascular disease and cardiomyopathy. Perfusion CMRI can quantify myocardial blood flow (MBF) and myocardial perfusion reserve index. Hibernating myocardial segments demonstrate reduced resting MBF.