Technical advances in cardiovascular magnetic resonance (CMR) T2-weighted imaging have allowed in-vivo visualization and accurate quantification of myocardial edema, a substantial feature of myocardial ischemic/reperfusion injury. In acute myocardial infarction, myocardial edema imaging can be used to differentiate acute from chronic irreversible injury. This can also be of particular importance in the sub-acute phase in which laboratory markers are equivocal or in the setting of missed infarction. Furthermore, CMR-T2-weighted edema imaging identifies the area at risk and thus can be used to quantify the area of salvaged myocardium after coronary reperfusion by comparing the area of irreversible injury to that of the myocardium at risk. Another exciting area of research employs edema imaging to monitor the effect of interventions that target reduction of myocardial edema. The premise is that myocardial edema results in vascular compression, and may thus contribute to failure of myocardial tissue reperfusion even after reestablishing the patency of the infarct related coronary artery. This can be used to monitor the efficiency of novel therapeutic strategies targeting post-infarction myocardial edema. This mini review will address the pathophysiological, clinical and some technical issues related to edema imaging in acute myocardial infarction. Some recent patents on myocardial edema, Magnetic resonance imaging and myocardial infarction are also addressed.
Keywords: Myocardial edema, T2-weighted, Magnetic resonance imaging, Myocardial infarction, Acute coronary syndromes, Reperfusion injury, Area at risk, Myocardial salvage, Myocardial viability