Sub-voxel Tissue Characterization with In-Vivo MRI

描述（由申请人提供）：本项目的总体目标是开发和实施通过磁共振成像（MRI）定量表征组织的新方法。水在组织中的微观划分反映了可能通过不同的MRI测量来探测的潜在重要的结构特性。特别是，水的扩散和核磁共振（NMR）弛豫不能描述在许多组织中的单一成分。取得了一定的成功，这些属性的多个组件的特性已被提出和研究，试图提取有关的微观解剖水室，他们来自特定的信息。用于获取和分析亚体素特征的新的、有效的方法的进一步开发和应用有望用于评估各种组织（特别是神经和肌肉）中的结构和病理生理。本文提出的研究将为此类研究开发新的方法，并提供对正常和病理条件下白色物质和肌肉中MRI对比度的生物学基础的更完整的理解。对模型组织的实验研究将建立水扩散、纵向和横向弛豫和磁化转移的全面和定量的体内描述，以及它们如何相互关联以及它们所来源的物理隔室。然后，这些观察结果可以用于设计新的MRI方法，这些方法更具体地描述组织微观结构。其中一个例子是，基于白色物质的详细隔室模型，开发可视化和量化脑中髓鞘含量的高效且有效的MRI方法。公共卫生相关性：MRI是一种广泛使用的诊断成像方式，能够相对无创地显示软组织。MRI中的对比度是由体内水分子彼此之间的许多复杂相互作用以及其局部环境的物理和化学特性引起的。这项研究计划旨在更好地将MRI对比度与神经组织和骨骼肌中的特定显微解剖特征联系起来。这项工作具有广泛的潜在影响MRI的诊断和预后能力的各种疾病和损伤。

DESCRIPTION (provided by applicant): The overall aims of this project are to develop and implement novel methods for quantitative characterization of tissue by magnetic resonance imaging (MRI). The microscopic compartition of water in tissues reflects potentially important structural properties that may be probed by diverse MRI measurements. In particular, water diffusion and nuclear magnetic resonance (NMR) relaxation cannot be described by single components in many tissues. With some success, multiple component characterization of these attributes has been proposed and studied in an attempt to extract specific information about the micro-anatomical water compartments from which they are derived. The further development and application of novel, effective methods for acquiring and analyzing sub-voxel characteristics promises to be useful for assessing structure and pathophysiology in various tissues, particularly nerve and muscle. The studies proposed herein will develop new methods for such studies and provide a more complete understanding of the biological basis of MRI contrast in white matter and muscle, in normal and pathological conditions. Experimental studies on model tissues will establish comprehensive and quantitative in vivo descriptions of water diffusion, longitudinal and transverse relaxation, and magnetization transfer, and how they correlate to each other and the physical compartments from which they are derived. These observations can then be used to design novel MRI methods, which are more specific for depicting tissue microstructure. One example, amongst others, is the aim to develop efficient and effective MRI methods of visualizing and quantifying myelin content in the brain based on detailed compartmental models of white matter. PUBLIC HEALTH RELEVANCE: MRI is a widespread diagnostic imaging modality capable of relatively non-invasive visualization of soft tissue. The contrast in MRI results from many complex interactions of water molecules in the body with each other and the physical and chemical characteristics of their local environments. This research program aims to better relate MRI contrast to specific micro-anatomical characteristics in neural tissue and skeletal muscle. This work has broad potential impact the diagnostic and prognostic capabilities of MRI for a wide array of diseases and injuries.