Sub-voxel Tissue Characterization with In-Vivo MRI

描述（由申请人提供）： 该项目的总体目标是开发和实施新的方法，通过磁共振成像（MRI）对组织进行定量体内表征。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。随着一些有限的成功，这些属性的多个组件表征已被提出和研究，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高效和有效方法的进一步发展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使用MRI的房室研究提供更快、更准确和更多信息的技术。对模型组织的实验研究将建立水扩散、纵向松弛和横向松弛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，这些观察结果将用于设计新的MRI方法，这些方法更具体地描述体内组织的微观结构。其中一个例子是，基于白色物质中的弛豫和扩散的详细隔室模型，开发可视化和量化脑中髓鞘含量的快速且容易实现的MRI方法。

DESCRIPTION (provided by applicant): The overall aims of this project are to develop and implement novel methods for quantitative, in vivo 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 limited 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 of efficient and effective methods for acquiring and analyzing subvoxel characteristics promises to be useful for assessing structure and pathophysiology in various tissues, particularly nerve and muscle. The studies proposed herein will provide faster, more accurate, and more informative techniques for compartmental studies using MRI. Experimental studies on model tissues will establish comprehensive and quantitative in vivo descriptions of water diffusion, longitudinal relaxation and transverse relaxation, and how they correlate to each other and the physical compartments from which they are derived. These observations will then be used to design novel MRI methods, which are more specific for depicting tissue microstructure in vivo. One example, amongst others, is the aim to develop rapid and easily implemented MRI methods of visualizing and quantifying myelin content in the brain based on detailed compartmental models of relaxation and diffusion in white matter.