Chul Hwan Park1, Eui-Young Choi2, Young Won Yoon2, Hyuck Moon Kwon2, Bum Kee Hong2, Byoung Kwon Lee2, Pil-Ki Min2, Andreas Greiser3, Mun Young Paek4, Sung Ho Hwang1, Tae Hoon Kim5. 1. Department of Radiology and Research Institute of Radiological Science, Yonsei University Health System, Seoul 135-720, Republic of Korea. 2. Division of Cardiology, Heart Center, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea. 3. Healthcare Sector, Siemens AG, Erlangen, Germany. 4. Siemens Ltd., Seoul, Republic of Korea. 5. Department of Radiology and Research Institute of Radiological Science, Yonsei University Health System, Seoul 135-720, Republic of Korea. Electronic address: thkim1@yuhs.ac.
Abstract
PURPOSE: This study evaluates myocardial edema by quantitative T2 mapping in patients with acute myocardial infarction (AMI) and compares the lateral extent of myocardial edema with those of infarcted and dysfunctional myocardium. MATERIALS AND METHODS: Cardiac magnetic resonance images (MRIs) of 31 patients (M:F=29:2, mean age: 52.5±10.8years) with AMI were reviewed. On cine-MRI, all short axis images of the left ventricle (LV) were divided into 60 sectors. The regional wall motion of each sector was calculated as follows: systolic wall thickening (SWT, %)=[(LV wall thicknessES-LV wall thicknessED)/LV wall thicknessED]*100. Dysfunctional myocardium was defined as sectors with decreased SWT lower than 40%. On LGE-images, myocardial infarction was defined as an area of hyper-enhancement more than 5 SDs from the remote myocardium. On T2 map, myocardial edema was defined as an area in which T2 values were at least 2 SDs higher than those from remote myocardium. The lateral extents of infarcted myocardium, myocardial edema, and dysfunctional myocardium were calculated as the percentage of central angles ((central angle of the involved myocardium/360)*100 (%)) and then compared. RESULTS: The lateral extent of myocardial edema was slightly larger than that of infarcted myocardium (37.4±13.3% vs. 35±12.9%, p<0.01). The lateral extent of dysfunctional myocardium (50.6±15.3%) was significantly larger than that of infarcted myocardium or myocardial edema (p<0.001). CONCLUSIONS: The lateral extent of myocardial edema beyond the infarcted myocardium might be narrow, but the dysfunctional myocardium could be significantly larger than myocardial edema, suggesting stunned myocardium without edema.
PURPOSE: This study evaluates myocardial edema by quantitative T2 mapping in patients with acute myocardial infarction (AMI) and compares the lateral extent of myocardial edema with those of infarcted and dysfunctional myocardium. MATERIALS AND METHODS: Cardiac magnetic resonance images (MRIs) of 31 patients (M:F=29:2, mean age: 52.5±10.8years) with AMI were reviewed. On cine-MRI, all short axis images of the left ventricle (LV) were divided into 60 sectors. The regional wall motion of each sector was calculated as follows: systolic wall thickening (SWT, %)=[(LV wall thicknessES-LV wall thicknessED)/LV wall thicknessED]*100. Dysfunctional myocardium was defined as sectors with decreased SWT lower than 40%. On LGE-images, myocardial infarction was defined as an area of hyper-enhancement more than 5 SDs from the remote myocardium. On T2 map, myocardial edema was defined as an area in which T2 values were at least 2 SDs higher than those from remote myocardium. The lateral extents of infarcted myocardium, myocardial edema, and dysfunctional myocardium were calculated as the percentage of central angles ((central angle of the involved myocardium/360)*100 (%)) and then compared. RESULTS: The lateral extent of myocardial edema was slightly larger than that of infarcted myocardium (37.4±13.3% vs. 35±12.9%, p<0.01). The lateral extent of dysfunctional myocardium (50.6±15.3%) was significantly larger than that of infarcted myocardium or myocardial edema (p<0.001). CONCLUSIONS: The lateral extent of myocardial edema beyond the infarcted myocardium might be narrow, but the dysfunctional myocardium could be significantly larger than myocardial edema, suggesting stunned myocardium without edema.