Cardiac MR imaging of hemorrhagic reperfusion injury after myocardial infarction

项目总结 心力衰竭(HF)是影响美国约510万人的巨大健康负担，是 每年造成25万人死亡。大约50%的心衰是由心肌缺血引起的，需要 立即恢复冠脉血流至受影响的心肌。然而，再灌注的成功 部分受限于心肌内出血，即血管内物质沉积到 心肌。出血性再灌注损伤的发生率很高，患者发生 不良的左心室重构，致命心律失常的风险，收缩功能受损，并在 更高的利率。最近的磁共振成像技术改进了对再灌注损伤的评估， 然而，MRI对比度与再灌注损伤之间的联系尚不清楚，且缺乏特异性。 致IMH。改进的IMH成像和对其时空演变的准确了解可能是 是为患者提供最佳医疗治疗的关键，也是识别最有可能患上 不良的心脏重塑。总的目标是研究出血的磁特性和 开发对出血具有更高特异性的MRI技术。新的核磁共振技术允许无创 评估组织的磁化率，并可靶向组织铁。因此，我们假设 MRI心肌磁化率成像可定位出血性心肌。我们将表演 在猪再灌注损伤模型上进行临床前实验，以验证这些方法，并与 传统的磁共振对比，并开发磁共振方法成像活体动物。

PROJECT SUMMARY Heart failure (HF) is an enormous health burden affecting approximately 5.1 million people in the US and is the cause of 250,000 deaths each year. Approximately 50% of HF is caused by myocardial ischemia and requires immediate restoration of coronary blood flow to the affected myocardium. However, the success of reperfusion is partly limited by intramyocardial hemorrhage, which is the deposition of intravascular material into the myocardium. Hemorrhagic reperfusion injury has high prevalence and patients have a much greater risk of adverse left ventricular remodeling, risk of fatal arrhythmia, impaired systolic function and are hospitalized at a greater rate. Recent magnetic resonance imaging techniques have improved assessment of reperfusion injury, however, the association between MRI contrasts and reperfusion injury is highly unclear, and lacks specificity to IMH. Improved imaging of IMH and accurate knowledge about its spatial and temporal evolution may be essential for delivery of optimal medical therapy in patients and critical to identify patients most at risk for adverse ventricular remodeling. The overall goal is to investigate the magnetic properties of hemorrhage and develop MRI techniques with improved specificity to hemorrhage. New MRI techniques permit noninvasive assessment of the magnetic susceptibility of tissues and can target tissue iron. Therefore, we hypothesize that MRI imaging of myocardial magnetic susceptibility can map hemorrhagic myocardium. We will perform preclinical experiments in a pig model of reperfusion injury to validate these methods, compare them with conventional MR contrasts and develop MR methods for imaging live animals.