title: Investigation of T2-weighted signal intensity of infarcted myocardium and its correlation with delayed enhancement magnetic resonance imaging in a porcine model with reperfused acute myocardial infarction.
abstract: To assess the signal pattern in T2-weighted images (T2WI) and determine its relation to persistent microvascular obstruction (PMO) and intramyocardial hemorrhage in a porcine model with reperfused acute myocardial infarction. Left anterior descending artery was occluded (90 or 180 min) and reperfused (90 min). T2WI and delayed-enhanced magnetic resonance images (DE-MRI) were acquired. The T2WI signal pattern, T2WI contrast ratio, PMO, and intramyocardial hemorrhage were evaluated, and their interrelationships were analyzed. The infarct area on T2WI was recorded as a homogeneous high-intensity signal or as low- or iso-intensity signals. The contrast ratio of the T2WI in the cases with PMO was significantly lower than that in those without PMO (1.38 +/- 0.25 vs. 1.89 +/- 0.31, P < 0.05), and it showed significant inverse correlation with the extent of PMO observed in DE-MRI images (r =-0.8, P < 0.05). The extent of PMO correlated strongly with that of intramyocardial hemorrhage (r = 0.97, P < 0.05). The abnormal signal area in the T2WI was larger than the infarct area in the DE-MRI images (47.0 +/- 9.9% vs. 37.8 +/- 9.9%, P < 0.05) and the infarct area observed after TTC staining (47.0 +/- 9.9% vs. 37.4 +/- 8.4%, P < 0.05). We observed variable T2WI signal patterns for the infarcted myocardium. Lower T2WI contrast ratios significantly correlated with the extent of PMO in DE-MRI and intramyocardial hemorrhage in the gross specimen.
authors.affiliation: Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea.
authors.forename: Seong Hoon
authors.initials: SH
authors.lastname: Choi
authors.forename: Joon-Won
authors.initials: JW
authors.lastname: Kang
authors.forename: Sang-Tae
authors.initials: ST
authors.lastname: Kim
authors.forename: Byung Han
authors.initials: BH
authors.lastname: Lee
authors.forename: Eun Ju
authors.initials: EJ
authors.lastname: Chun
authors.forename: Karl H
authors.initials: KH
authors.lastname: Schuleri
authors.forename: Sang Il
authors.initials: SI
authors.lastname: Choi
authors.forename: Tae-Hwan
authors.initials: TH
authors.lastname: Lim
mesh_terms: D000818:Animals; D003287:Contrast Media; D003326:Coronary Circulation; D004195:Disease Models, Animal; D006470:Hemorrhage / Q000473:pathology* / Q000503:physiopathology / Q000628:therapy; D008279:Magnetic Resonance Imaging; D008833:Microcirculation; D009203:Myocardial Infarction / Q000473:pathology* / Q000503:physiopathology / Q000628:therapy; D015425:Myocardial Reperfusion; D009206:Myocardium / Q000473:pathology*; D012720:Severity of Illness Index; D013552:Swine
chemical_list: D003287:Contrast Media