Cardiac MR imaging of hemorrhagic reperfusion injury after myocardial infarction

项目摘要 心力衰竭（HF）是一种巨大的健康负担，影响美国约510万人，并且是世界上最严重的心力衰竭。 每年造成25万人死亡。大约50%的HF是由心肌缺血引起的， 立即恢复受影响心肌的冠状动脉血流。然而，再灌注的成功 部分受到心肌内出血的限制，这是血管内物质沉积到 心肌出血性再灌注损伤的患病率很高，患者的出血风险要大得多。 不利的左心室重塑，致命性心律失常的风险，收缩功能受损，并住院治疗， 更高的速率。最近的磁共振成像技术改善了再灌注损伤的评估， 然而，MRI对比度和再灌注损伤之间的关系尚不清楚，且缺乏特异性 关于IMH IMH的改进成像和关于其空间和时间演变的准确知识可能是 对于为患者提供最佳药物治疗至关重要，对于识别最有风险的患者至关重要。 不利的心室重塑。总体目标是研究出血的磁特性， 开发对出血具有更高特异性的MRI技术。新的MRI技术允许无创 评估组织的磁化率，并且可以靶向组织铁。因此，我们假设， MRI心肌磁化率成像可以标测出血心肌。我们将执行 在猪再灌注损伤模型中进行临床前实验以验证这些方法，将它们与 传统的MR对比，并开发用于活体动物成像的MR方法。

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.