HIGH RESOLUTION MRI OF MYOCARDIAL DEFORMATION

心肌变形的高分辨率 MRI

• 批准号: 2028575
• 负责人: ELLIOT R MCVEIGH
• 金额: $ 32.07万
• 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/2028575
• 关键词: 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（竞争性更新） 应用）。在这笔赠款的第一个资助期内，我们开发了 用于获取测量值的新颖成像和分析技术 心肌应变在整个过程中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 通过模拟和实验。开发的方法是为了 实现高空间分辨率立即导致强大的临床 现在用于表征正常和缺血的协议 人心。在该项目的下一阶段，我们计划扩展我们的高 空间分辨率技术转化为高时间分辨率技术 目的是测量异位电激活之间的关系 以及正常、缺血和[衰竭]心脏的机械收缩。 我们的初步数据表明我们可以解析心肌的“脉搏” 从起搏部位发出的收缩，绕着左侧传播 心室，并汇聚于心脏的相对壁上。这 传播发生在起搏刺激后l50ms内，并且 速度与方向相关。 我们计划调查相互作用 通过追求心肌的机械和电特性 以下具体目标：（1）开发新颖的成像序列 用于测量机械传播的空间和时间分辨率 心室起搏期间的三维收缩。 (2) 树立形象 分析方法将新的标记模式纳入高时态 时空力学行为的分辨率估计 心。这些新功能将用于回答以下问题 心脏生理学的基本问题：（3）心脏的模式是什么？ 心室不同起搏部位的机械激活？ (4) 如何 缺血区域的存在是否会改变这种机械模式 激活？。 [(5) 起搏引起增强的机制是什么？ 扩张型心肌病心脏的心室功能？这 心脏成像方法的发展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 机械预牵拉在引起心律失常、起搏导联中的作用 改善衰竭心脏心室功能的放置，以及 各个区域完成的外部工作的重新分配 心。]