Time-Evolution of Edema in Reperfused Acute Myocardial Infarction: Implications for Assesment of Area-At-Risk

Veronica L. M. Rundell¹, Avinash Kali¹, Xiangzhi Zhou¹, Ying Liu¹, Richard L. Q. Tang¹, Andreas Kumar², Rohan Dharmakumar¹

T2-weighted MRI of acute myocardial infarction (AMI) has been used to determine Area-At-Risk. To investigate the resolution time of edema following ischemia-reperfusion injury, a canine model of reperfused AMI was investigated using both T₂ mapping and T₂ STIR protocols before and during infarction and again on days 2, 5, 7 and 56 following reperfusion. The percent volume of hyperintense myocardial regions (edema) peaked on day 2 and 5, respectively on T₂-STIR images and T₂ maps. Hyperintensity resolved to pre-infarct levels by week 8. Imaging approach and time to imaging may be key factors in determining Area-at-Risk and salvagable myocardium.