Visualizing the cardiac conduction network using MR microscopy and diffusion

使用 MR 显微镜和扩散可视化心脏传导网络

• 批准号: 8903567
• 负责人: JOHN Robert FORDER
• 金额: $ 66.21万
• 依托单位: UNIVERSITY OF FLORIDA
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-01 至 2016-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8903567
• 关键词: Age; Anatomy; Anisotropy; Apex of the Heart; Arrhythmia; Atlases; Brain; Cardiac; Cardiac Myocytes; Cardiac ablation; Cardiomyopathies; Cells; Clinical; Clinical Management; Congenital Heart Defects; Contracts; Contrast Media; Coupled; Data; Data Set; Detection; Diabetes Mellitus; Diffusion; Female; Fiber; Florida; Future; Gender; Health; Heart; Heart Arrest; Heart Atrium; Heart Diseases; Histology; Hour; Image; In Vitro; Incidence; Internet; Intervention; Investigation; Ischemia; Laboratories; Lead; Left; Length; Life; Location; Magnetic Resonance; Magnetic Resonance Imaging; Maps; Methods; Microscopy; Modeling; Monitor; Muscle Cells; Muscle Contraction; Myocardial Contraction; Myocardial tissue; Myocardium; Nature; Noise; Nutrient; Oryctolagus cuniculus; Publications; Purkinje Cells; Relaxation; Resolution; Running; Sampling; Series; Sex Characteristics; Signal Transduction; Staining method; Stains; Structure; Structure of purkinje fibers; System; Techniques; Temperature; Testing; Time; Tissue Viability; Tissues; Validation; Ventricular; Ventricular septum; Work; base; clinically significant; data acquisition; design; improved; in vivo; light microscopy; male; mathematical model; neurofilament; oxygen transport; research study; sudden cardiac death; tissue fixing; young adult

DESCRIPTION (provided by applicant): The heart is responsible for transporting oxygen and nutrients to all tissues in the body, and it performs this function through the coordinated contraction of muscle cells. When coordination of these contractions occurs, the heart fibrillates, or stops beating. The systems of specialized cells that are responsible for this coordination are the cardiac conducting network, commonly referred to as the Purkinje network. These specialized muscle cells rapidly conduct signals to contract, so that the heart tissue at the base of the heart contracts at nearly the same time as tissue at the apex of the heart. Although we have known about these specialized cells for over a hundred years, the only way we are currently able to see them is if we remove the heart, and examine pieces of it under light microscopy. These current techniques are labor intensive, and result in destruction of tissue. We have developed a non-invasive means to determine the anatomical location of these specialized cells using magnetic resonance microscopy and diffusion imaging. Using magnets at the National High Field Magnet Laboratory in Gainesville, Florida, we have obtained the highest resolution MR images to date of myocardial tissue (7um isotropic resolution), and performed diffusion imaging at resolutions down to 40um. We are able to visualize the atrial-ventricular node, conducting bundle, left and right bundle branches, and subsequent fibers that extend down the ventricular septum of the heart and into the ventricular cavities (as free-running Purkinje fibers). We propose to further improve our ability to discriminate these fibers from cardiac muscle cells, and to construct atlases of the conduction network to aid in future modeling. We will also compare the anatomy of this network in both male and female young adults, since the incidence of sudden cardiac death is dramatically different between the genders at this age.

描述（申请人提供）：心脏负责将氧气和营养物质输送到体内的所有组织，并通过肌肉细胞的协调收缩来执行此功能。当这些收缩协调发生时，心脏就会颤动， 或停止跳动。负责这种协调的专门细胞系统是心脏传导网络，通常称为浦肯野网络。这些专门的肌肉细胞快速传导收缩信号，使得心脏底部的心脏组织几乎与心尖部的组织同时收缩。尽管我们对这些特殊细胞的了解已有一百多年的历史，但目前我们能够看到它们的唯一方法是取出心脏，并在光学显微镜下检查它的碎片。目前的这些技术是劳动密集型的，并且会导致组织破坏。我们开发了一种非侵入性方法，利用磁共振显微镜和扩散成像来确定这些特殊细胞的解剖位置。使用佛罗里达州盖恩斯维尔国家高场磁体实验室的磁体，我们获得了迄今为止最高分辨率的心肌组织 MR 图像（7um 各向同性分辨率），并以低至 40um 的分辨率进行扩散成像。我们能够看到房室结、传导束、左束支和右束支，以及沿着心脏的室间隔延伸到心室腔的后续纤维（作为自由运行的浦肯野纤维）。我们建议进一步提高区分这些纤维和心肌细胞的能力，并构建传导网络图集以帮助未来建模。我们还将比较男性和女性年轻人的这个网络的解剖结构，因为这个年龄的性别之间的心源性猝死的发生率有显着差异。