Uncovering the time dependent diffusion coefficient in neural tissue with MRI

利用 MRI 揭示神经组织中的时间依赖性扩散系数

• 批准号: 10673746
• 负责人: Kevin D Harkins
• 金额: $ 41.44万
• 依托单位: VANDERBILT UNIVERSITY MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-09-24 至 2025-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10673746
• 关键词: 3-Dimensional; Age; Animal Experiments; Animal Model; Axon; Brain; Characteristics; Chemical Injury; Clinical; Complex; Computer Models; Dependence; Diagnosis; Diameter; Diffusion; Diffusion Magnetic Resonance Imaging; Disease; Exhibits; Ferrets; Geometry; Goals; Health; Heterogeneity; Histology; Human; Image; Magnetic Resonance Imaging; Measurement; Measures; Methods; Modeling; Myelin; Neurons; Physiologic pulse; Population; Property; Protocols documentation; Rattus; Role; Signal Transduction; Source; Spinal Cord; Staging; Structure; Testing; Time; Tissue Model; Tissues; Validation; Variant; Water; White Matter Disease; Work; diffusion weighted; experimental study; human imaging; human subject; improved; nervous system disorder; neural; sex; simulation; temporal measurement; three-dimensional modeling; tool; water diffusion; white matter

The overarching goal of this project is to reveal the microstructural features that underlie the diffusion-time dependent changes in the apparent diffusion coefficient measured diffusion weighted magnetic resonance imaging (DWI) in neural tissue. While time dependent changes in the diffusion coefficient have been measured in numerous previous studies of neural tissue, the exact microstructural characteristics of that underly these changes remain unclear. Uncovering the microstructure that underly these measurements could improve the diagnosis, staging and differentiation of numerous neurological diseases that otherwise show nonspecific changes with DWI. We propose that time dependent changes in diffusion originate primarily from three sources: mean axon diameter, heterogeneity of extra-axonal space, and orientation dispersion. Within this project, we propose to (1) develop and use numerical simulations to test the sensitivity of time dependent diffusion to tissue microstructure, (2) validate time dependent changes in the diffusion coefficient in specific animal models that vary axon diameter, heterogeneity of extra-axonal space, and complexity of white matter, and (3) provide baseline estimates of the time dependent diffusion coefficient and the variability in these measurements in a population of healthy human controls.

该项目的总体目标是揭示微结构特征， 表观扩散系数的扩散时间依赖性变化 神经组织的加权磁共振成像（DWI）。随着时间的推移， 扩散系数已经在许多以前的神经组织研究中测量， 这些变化背后的确切微观结构特征仍不清楚。揭开 作为这些测量基础的微观结构可以改善诊断、分期和 许多神经系统疾病的分化，否则显示非特异性变化， 酒后驾车我们提出，扩散的时间依赖性变化主要源于三个 来源：平均轴突直径、轴突外空间的不均匀性和取向分散。 在这个项目中，我们建议（1）开发和使用数值模拟来测试 时间相关扩散对组织微结构的敏感性，（2）验证时间相关扩散 在特定的动物模型中扩散系数的变化改变轴突直径， 轴索外空间异质性和白色物质的复杂性，以及（3）提供基线 这些测量中的时间依赖性扩散系数和可变性的估计 在健康对照人群中。