HIGH-RESOLUTION MRI OF MYOCARDIAL DEFORMATION

心肌变形的高分辨率 MRI

• 批准号: 3473366
• 负责人: ELLIOT R MCVEIGH
• 金额: $ 10.57万
• 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 1996-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3473366
• 关键词: clinical biomedical equipment; diagnosis quality /standard; dogs; heart contraction; heart dimension /size; heart disorder diagnosis; heart function; heart imaging /visualization /scanning; myocardial ischemia /hypoxia; noninvasive diagnosis; phantom model

The overall objective of this proposal is to develop, implement, and evaluate high-resolution magnetic resonance imaging methods, specifically myocardial tagging, for acquiring a time series of localized strain measurements in the myocardium of the dog. This will allow, for the first time, noninvasive measurements of the transmural dependence of myocardial deformation. The absence of such a noninvasive method has been a major limitation in the field of cardiac mechanics. Because knowledge of local deformation patterns is required to study the relationship between fiber shortening and heart wall thickening in normal and diseased states, investigators have resorted to implanting arrays of radiopaque markers in the myocardium and tracking the motion of these markers with biplane cineradiography. This is now the standard method for performing measurements of strain in the myocardium. With the development of a specialized probe, myocardial tagging pulse sequences and strain calculation algorithms, equivalent, if not superior, measurements of strain may be obtained noninvasively. Thus the specific aims of this proposal are: (1) To refine and validate high-resolution myocardial tagging techniques. This involves the design and construction of a specialized probe, optimization and validation of MRI-derived strain estimates with simulations and experiments in phantoms, and the comparison of selected methods in vivo. (2) To determine the resolution required for sampling myocardial deformation during contraction that permits the calculation of strain in local regions of the heart wall using a linear model. (3) To determine whether myocardial deformation is homogenous or heterogeneous in local and remote regions of the left ventricle. Using the techniques described in this application, we will make strain estimates through the heart wall with an isotropic resolution on the order of 3 mm3. The accomplishment of these aims will have a significant effect on research in cardiac mechanics. Most important, for the first time, investigators will have the ability to measure the local mechanics of myocardial contraction noninvasively.

本提案的总体目标是制定、实施和 评估高分辨率磁共振成像方法，特别是 心肌标记，用于获取局部应变的时间序列 在狗的心肌中的测量。 这将允许，对于第一个 心肌细胞跨壁依赖性的时间、非侵入性测量 变形 缺乏这种非侵入性方法一直是一个主要的问题， 心脏力学领域的局限性。 因为当地的知识 变形模式是需要研究纤维之间的关系 缩短和心脏壁增厚， 研究者已经求助于植入不透射线标记的阵列， 心肌和跟踪这些标记的运动与双平面 电影放射照相术 这是现在执行的标准方法 测量心肌中的应变。 负责制订 专用探头、心肌标记脉冲序列和应变 计算算法，等效（如果不是上级）应变测量 可以非侵入性地获得。 因此，这项建议的具体目标 为： (1)完善和验证高分辨率心肌标记技术。 这涉及到设计和建造一个专门的探头， MRI衍生应变估计的优化和验证， 模拟和实验中的幻影，并比较选定的 体内方法。 (2)确定心肌采样所需的分辨率 在收缩过程中的变形，允许计算应变， 使用线性模型的心脏壁的局部区域。 (3)确定心肌变形是否均匀或 在左心室的局部和远端区域中是异质的。 使用 在本申请中描述的技术，我们将进行应变估计 以3mm3量级的各向同性分辨率穿过心脏壁。 这些目标的实现将对研究产生重大影响 心脏机械学 最重要的是，调查人员第一次 将有能力测量心肌局部力学 非侵入性收缩。