Contrast enhanced magnetic resonance imaging for assessing myocardial perfusion and reperfusion injury

Abstract

Noninvasive cardiac imaging techniques are being used with increasing frequency to guide interventional procedures as they are being applied to ischemic heart disease and to assess their effects. These interventions relieve coronary artery stenoses that produce myocardial ischemia, and improve myocardial perfusion after thrombolytic therapy. New fast and ultra-fast magnetic resonance imaging (MRI) techniques have ameliorated previous limitations of slow temporal resolution. With these methods, high resolution images of the heart are obtained in seconds or fractions of a second. Thus, MRI may now image the first pass of a contrast agent bolus through the heart. Recent experimental, and some limited clinical experience indicate that dynamic contrast enhanced cardiac MRI is a valuable imaging technique for myocardial perfusion imaging. Contrast enhanced MRI might be used to 1) define zones of myocardial ischemia (perfusion defects) based upon rapid imaging during the first pass of a contrast agent; 2) differentiate occlusive from reperfused infarctions; and 3) determine myocardial viability.