Relation Between Signal Intensity on T2-Weighted MR Images and Presence of Microvascular Obstruction in Patients With Acute Myocardial Infarction

OBJECTIVE. In experimental animal models and human autopsy studies, hemorrhagic infarction caused by microvascular injury has been detected after coronary reperfusion. The purpose of this study was to determine whether detection of myocardial edema with T2-weighted MRI is influenced by the presence of microvascular obstruction.SUBJECTS AND METHODS. Thirty-seven patients underwent black-blood fat-suppressed T2-weighted, rest perfusion, and late gadolinium-enhanced MRI 5.4 ± 3.1 days after the onset of acute myocardial infarction. On T2-weighted MR images, the signal intensity in relation to that of remote myocardium was determined in the late gadolinium-enhanced and periinfarction areas. Segment-based analysis was performed to determine whether the presence of microvascular obstruction influences the detection of myocardial edema.RESULTS. The averaged signal intensity in the late gadolinium-enhanced area without microvascular obstruction was significantly higher than the signal intensity in remote normal m...