HIGH RESOLUTION MRI OF MYOCARDIAL DEFORMATION

心肌变形的高分辨率 MRI

• 批准号: 2901134
• 负责人: ALBERT Clark LARDO
• 金额: $ 31.04万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-08-01 至 2002-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2901134
• 关键词: bioimaging /biomedical imaging; biomedical equipment development; clinical biomedical equipment; diagnosis quality /standard; dogs; heart contraction; heart dimension /size; heart disorder diagnosis; heart electrical activity; heart function; heart imaging /visualization /scanning; heart pacemaker tissue; heart ventricle; image processing; magnetic resonance imaging; myocardial ischemia /hypoxia; myocardium disorder; noninvasive diagnosis; phantom model

High Resolution MRI of Myocardial Deformation (competing renewal application). In the first funding period of this grant we have developed novel imaging and analysis techniques for acquiring measurements of myocardial strain with unprecedented spatial resolution over the entire left ventricle. These methods have been rigorously optimized and validated with simulations and experiments. The methods which were developed to achieve high spatial resolution have lead immediately to robust clinical protocols that are now being used to characterize the normal and ischemic human heart. In this next phase of the project we plan to extend our high spatial resolution techniques into high temporal resolution techniques with the goal to measure the relationship between ectopic electrical activation and mechanical contraction in the normal, ischemic, [and failing] heart. Our preliminary data show that we can resolve a "pulse" of myocardial contraction that emanates from a pacing site, travels around the left ventricle, and converges on the opposite wall of the heart. This propagation occurs during the l50ms after the pacing stimulation and the velocity is direction dependent. We plan to investigate the interaction of the mechanical and electrical properties of myocardium by pursuing the following specific aims: (1) Develop novel imaging sequences with the spatial and temporal resolution to measure the propagation of mechanical contraction in 3 dimensions during ventricular pacing. (2) Develop image analysis methods to incorporate new tagging patterns into the high temporal resolution estimates of the spatial-temporal mechanical behavior of the heart. These new capabilities will be used to answer the following fundamental questions of cardiac physiology: (3) What is the pattern of mechanical activation for different pacing sites on the ventricle? (4) How does the existence of an ischemic region alter this pattern of mechanical activation?. [(5) What is the mechanism by which pacing causes enhanced cardiac chamber function in hearts with dilated cardiomyopathy? This development in cardiac imaging methods will give us new tools to answer fundamental questions about ventricular function, such as the role of mechanical prestretch in causing arrhythmia, the effect of pacing lead placement on improving ventricular performance in the failing heart, and the redistribution of external work done by individual regions of the paced heart.]

心肌变形的高分辨率MRI（竞争更新 应用）。在这笔赠款的第一个资金期间，我们已经开发了 用于获取测量的新型成像和分析技术 整个空间分辨率的心肌菌株具有前所未有的空间分辨率 左心室。这些方法已经过严格优化和验证 与模拟和实验。开发的方法 实现高空间分辨率已立即导致稳定的临床 现在用于表征正常和缺血的协议 人心。在项目的下一个阶段，我们计划扩展高度 空间分辨率技术进入高时间分辨率技术 测量异位电活激活之间关系的目标 以及在正常，缺血性和[失败]心脏中的机械收缩。 我们的初步数据表明，我们可以解决心肌的“脉冲” 从起搏地点散发出的收缩，在左边旅行 心室，并在心脏的另一壁上收敛。这 在起搏刺激后的L50ms期间发生传播，并发生 速度取决于方向。 我们计划调查互动 通过追求心肌的机械和电气性能 以下特定目的：（1）用 空间和时间分辨率以测量机械的传播 心室起搏期间3维的收缩。 （2）开发图像 分析方法将新的标记模式纳入高时间 分辨率估计的空间机械行为的分辨率估计值 心。这些新功能将用于回答以下内容 心脏生理学的基本问题：（3） 心室上不同起搏位点的机械激活？ （4）如何 缺血区域的存在是否改变了这种机械模式 激活？。 [（5）起搏引起增强的机制是什么 心肌病的心脏腔室功能？这 心脏成像方法的开发将为我们提供新的工具来回答 有关心室功能的基本问题，例如 机械prestretch引起心律不齐，起搏铅的作用 放置在改善心脏的心室表现的位置，并且 节奏的各个区域所做的外部工作的重新分配 心。]