Quantitative T2 mapping after reperfusion therapy in patients with acute myocardial infarction: A comparison with late gadolinium enhancement and cine MR imaging.
OBJECTIVE
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.


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.
Department of Radiology and Research Institute of Radiological Science, Yonsei University Health System, Seoul 135-720, Republic of Korea.
Chul Hwan
CH
Park
Division of Cardiology, Heart Center, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea.
Eui-Young
EY
Choi
Division of Cardiology, Heart Center, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea.
Young Won
YW
Yoon
Division of Cardiology, Heart Center, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea.
Hyuck Moon
HM
Kwon
Division of Cardiology, Heart Center, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea.
Bum Kee
BK
Hong
Division of Cardiology, Heart Center, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea.
Byoung Kwon
BK
Lee
Division of Cardiology, Heart Center, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea.
Pil-Ki
PK
Min
Healthcare Sector, Siemens AG, Erlangen, Germany.
Andreas
A
Greiser
Siemens Ltd., Seoul, Republic of Korea.
Mun Young
MY
Paek
Department of Radiology and Research Institute of Radiological Science, Yonsei University Health System, Seoul 135-720, Republic of Korea.
Sung Ho
SH
Hwang
Department of Radiology and Research Institute of Radiological Science, Yonsei University Health System, Seoul 135-720, Republic of Korea. Electronic address: thkim1@yuhs.ac.
Tae Hoon
TH
Kim
D000208:Acute Disease; D003287:Contrast Media; D005260:Female; D005682:Gadolinium; D006801:Humans; D019028:Magnetic Resonance Imaging, Cine; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000503:physiopathology* / Q000628:therapy*; D015424:Reperfusion; D012189:Retrospective Studies
D003287:Contrast Media; D005682:Gadolinium
Cine MRI; Delayed enhancement; Myocardial edema; Myocardial infarction; T2 map