Late contrast enhancement by CMR: more than scar?

Excerpt

Cardiac magnetic resonance imaging (CMR) has long been recognized as an accurate and reliable means of evaluating cardiac anatomy and ventricular function. Considerable progress has been made in the field of CMR, providing accurate evaluation of myocardial ischemia and infarction [1, 2]. Contrast-enhanced CMR can be used to visualize the transmural extent of myocardial infarction with high spatial resolution [3‐5]. Infarcted myocardium appears hyperenhanced compared with normal myocardium when imaged by a delayed-enhancement MRI technique with the use of T1-weighted sequence after injection of gadolinium chelates. Late gadolinium-enhanced CMR can clearly delineate subendocardial infarction and the transmural extent of delayed enhancement potentially predicts functional outcome after revascularization in acute myocardial infarction and chronic ischemic heart disease. This indicates that the late enhancement technique can accurately discriminate between infarction and dysfunctional but viable myocardium. Experimental and clinical studies have shown that the extent of delayed enhancement is reproducible and closely correlates with the size of myocardial necrosis or infarct scar as determined by established in vitro and in vivo methods. Furthermore, CMR appears to be more sensitive than other imaging methods in detecting small subendocardial infarctions. …