Detection and Quantification of Myocardial Reperfusion Hemorrhage Using T2*-Weighted CMR
Detection and Quantification of Myocardial Reperfusion Hemorrhage Using T2*-Weighted CMR
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DOI：
10.1016/j.jcmg.2011.08.016
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发表时间：
2011-12-01
影响因子：
14
通讯作者：
Friedrich, Matthias G.
中科院分区：
文献类型：
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作者：
Kumar, Andreas;Green, Jordin D.;Friedrich, Matthias G.
目的 本研究的目的是根据离体金标准验证 T2* 加权心脏磁共振 (T2*-CMR) 用于体内再灌注出血的检测和定量，并研究出血与微血管阻塞、梗死面积和左心室 (LV) 功能参数的关系。 背景 出血可能导致心肌梗死的再灌注损伤，可能对患者管理具有重要意义。目前尚无有效的成像方法来评估体内再灌注出血。 T2*-CMR 显得很合适，因为它可以根据血红蛋白降解产物的磁场效应产生图像对比度。方法在 14 只杂种狗中，通过实验诱发心肌梗塞。再灌注后第 3 天，进行了体内 CMR 研究，包括出血的 T2* 加权梯度回波成像序列、左心室功能的标准序列以及微血管阻塞和心肌坏死的对比后序列。进行离体硫黄素 S 成像和氯化三苯基四唑 (TTC) 染色来评估微血管阻塞、出血和心肌坏死。由盲人观察者对图像进行分析，并进行比较统计。结果出血仅发生在梗死面积最大和微血管阻塞程度最严重的狗中，并且与左室功能参数更受损有关。在 TTC 染色的 40 个出血节段中，37 个 (92.5%) 在 T2*-CMR 上呈出血阳性（kappa = 0.96，体内/离体节段一致性 p < 0.01）。体内 T2*-CMR 测定的 13 个受影响组织切片的出血量与离体结果密切相关（每片 20.3 +/- 2.3% 对比 17.9 +/- 1.6%；Pearson r = 0.91；r(2) = 0.83，两者 p < 0.01）。体内 T2*-CMR 和离体 TTC 之间的出血量没有差异（平均差异 2.39 +/- 1.43%；p = 0.19）。结论 T2*-CMR 准确量化了体内心肌再灌注出血。出血与更严重的梗塞相关损伤有关。 （J Am Coll Cardiol Img 2011；4:1274-83）c 2011 年，美国心脏病学会基金会
OBJECTIVES The purpose of this study was to validate T2*-weighted cardiac magnetic resonance (T2*-CMR) for the detection and quantification of reperfusion hemorrhage in vivo against an ex vivo gold standard, and to investigate the relationship of hemorrhage to microvascular obstruction, infarct size, and left ventricular (LV) functional parameters.BACKGROUND Hemorrhage can contribute to reperfusion injury in myocardial infarction and may have significant implications for patient management. There is currently no validated imaging method to assess reperfusion hemorrhage in vivo. T2*-CMR appears suitable because it can create image contrast on the basis of magnetic field effects of hemoglobin degradation products.METHODS In 14 mongrel dogs, myocardial infarction was experimentally induced. On day 3 post-reperfusion, an in vivo CMR study was performed including a T2*-weighted gradient-echo imaging sequence for hemorrhage, standard sequences for LV function, and post-contrast sequences for microvascular obstruction and myocardial necrosis. Ex vivo, thioflavin S imaging and triphenyl-tetrazoliumchloride (TTC) staining were performed to assess microvascular obstruction, hemorrhage, and myocardial necrosis. Images were analyzed by blinded observers, and comparative statistics were performed.RESULTS Hemorrhage occurred only in the dogs with the largest infarctions and the greatest extent of microvascular obstruction, and it was associated with more compromised LV functional parameters. Of 40 hemorrhagic segments on TTC staining, 37 (92.5%) were positive for hemorrhage on T2*-CMR (kappa = 0.96, p < 0.01 for in vivo/ex vivo segmental agreement). The amount of hemorrhage in 13 affected tissue slices as determined by T2*-CMR in vivo correlated strongly with ex vivo results (20.3 +/- 2.3% vs. 17.9 +/- 1.6% per slice; Pearson r = 0.91; r(2) = 0.83, p < 0.01 for both). Hemorrhage size was not different between in vivo T2*-CMR and ex vivo TTC (mean difference 2.39 +/- 1.43%; p = 0.19).CONCLUSIONS T2*-CMR accurately quantified myocardial reperfusion hemorrhage in vivo. Hemorrhage was associated with more severe infarct-related injury. (J Am Coll Cardiol Img 2011;4:1274-83) c 2011 by the American College of Cardiology Foundation