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。组织中水的微观成分反映了潜在的重要结构特性，可以通过不同的MRI测量来探测。特别是，水的扩散和核磁共振弛豫不能用许多组织中的单一组分来描述。在一些成功的情况下，已经提出并研究了这些属性的多组分表征，试图提取有关微解剖水室的具体信息，这些水室是由这些属性派生的。获取和分析亚体素特征的新型有效方法的进一步发展和应用有望用于评估各种组织的结构和病理生理，特别是神经和肌肉。本文提出的研究将为此类研究开发新的方法，并提供更完整的了解正常和病理条件下白质和肌肉MRI对比的生物学基础。对模型组织的实验研究将建立全面和定量的体内水扩散、纵向和横向弛豫、磁化转移，以及它们如何相互关联以及它们产生的物理区室的描述。这些观察结果可以用来设计新的MRI方法，更具体地描绘组织微观结构。其中一个例子是，基于白质的详细区室模型，旨在开发高效和有效的MRI方法来可视化和量化大脑中的髓磷脂含量。公共卫生相关性：MRI是一种广泛的诊断成像方式，能够对软组织进行相对无创的可视化。MRI中的对比是由于体内水分子之间的许多复杂相互作用以及它们所在环境的物理和化学特征。本研究计划旨在更好地将MRI对比与神经组织和骨骼肌的特定微观解剖特征联系起来。这项工作对MRI对一系列疾病和损伤的诊断和预后能力具有广泛的潜在影响。

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.