Validation of Myocardial Edema in Acute Myocardial Infarction using Quantitative CT

Introduction Acute myocardial infarction (AMI) leads to accumulation of fluid in the interstitium as a result of enhanced cellular and vascular leakiness. Hence, myocardial edema is a hallmark of acute ischemic injury and can be used to delineate the extent of myocardium at risk, from which clinical decision on revascularization can be informed. Edema is not usually assessed by cardiac CT due to the similar enhancement (x-ray attenuation) between myocardium and water. We developed a functional CT technique for imaging myocardial edema. This method relies on tracer kinetic modeling of the retention of x-ray contrast in myocardium following a small bolus injection (BI). We validated this method in a pig model of reperfused AMI against a model-independent constant infusion (CI) method and cardiac magnetic resonance (CMR) T2-weighted imaging.