Quantitative Tracking of Edema, Hemorrhage, and Microvascular Obstruction in Subacute Myocardial Infarction in a Porcine Model by MRI
Quantitative Tracking of Edema, Hemorrhage, and Microvascular Obstruction in Subacute Myocardial Infarction in a Porcine Model by MRI
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DOI：
10.1002/mrm.22855
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发表时间：
2011-10-01
影响因子：
3.3
通讯作者：
Wright, Graham A.
中科院分区：
文献类型：
--
作者：
Ghugre, Nilesh R.;Ramanan, Venkat;Wright, Graham A.
急性心肌梗死后的病理生理反应包括水肿、出血、微血管阻塞以及细胞损伤。这些过程在整个梗塞愈合过程中的体内进化还没有得到很好的描述。我们研究的目的是在猪的心肌梗死模型上用MRI定量监测这些机制的时间进程。10头猪在冠状动脉闭塞前接受了MRI检查，并在梗塞后第2天、第1周、第2周、第4周和第6周进行了分组研究。使用定量T2和T2*图分别进行组织特征描述以识别水肿和出血。MRI增强扫描用于显示脑梗塞/微血管阻塞。炎症反应由T2波动反映，但在第2天，水肿和出血对T2有相反的作用。出血(所有形式)和矿化(钙)可以通过T2*在有水肿的情况下识别。微血管阻塞和T2*异常同时消失，提示这两种现象在愈合过程中密切相关。我们的研究表明，定量T2和T2*标测技术可以进行区域、纵向和跨受试者的比较，并对组织学和组织重建过程有深入的了解。这样的活体特征将对心肌梗死的严重程度分级和评估治疗策略非常重要，可能会改善临床结果。Magn Reson Med 66：1129-1141,2011。(C)2011年Wiley-Liss，Inc.
Pathophysiological responses after acute myocardial infarction include edema, hemorrhage, and microvascular obstruction along with cellular damage. The in vivo evolution of these processes simultaneously throughout infarct healing has not been well characterized. The purpose of our study was to quantitatively monitor the time course of these mechanisms by MRI in a porcine model of myocardial infarction. Ten pigs underwent MRI before coronary occlusion with subgroups studied at day 2 and weeks 1, 2, 4, and 6 post-infarction. Tissue characterization was performed using quantitative T2 and T2* maps to identify edema and hemorrhage, respectively. Contrast-enhanced MRI was used for infarct/microvascular obstruction delineation. Inflammation was reflected by T2 fluctuations, however at day 2, edema and hemorrhage had counter-acting effects on T2. Hemorrhage (all forms) and mineralization (calcium) could be identified by T2* in the presence of edema. Simultaneous resolution of microvascular obstruction and T2* abnormality suggested that the two phenomenon were closely associated during the healing process. Our study demonstrates that quantitative T2 and T2* mapping techniques allow regional, longitudinal, and cross-subject comparisons and give insights into histological and tissue remodeling processes. Such in vivo characterization will be important in grading severity and evaluating treatment strategies for myocardial infarction, potentially improving clinical outcomes. Magn Reson Med 66: 1129-1141, 2011. (C) 2011 Wiley-Liss, Inc.