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)对组织进行定量的活体表征。水在组织中的微观分配反映了潜在的重要结构特性，这些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(核磁共振)弛豫在许多组织中不能用单一的成分来描述。虽然取得了一些有限的成功，但已经提出并研究了这些属性的多组分表征，试图提取关于它们所源自的微解剖水室的特定信息。获得和分析亚体素特征的有效方法的进一步发展有望有助于评估各种组织的结构和病理生理学，特别是神经和肌肉。 本文提出的研究将为使用MRI进行分室研究提供更快、更准确和更有信息量的技术。对模型组织的实验研究将建立关于水扩散、纵向松弛和横向松弛的全面和定量的活体描述，以及它们如何相互关联，以及它们产生的物理间隔。这些观察结果将被用来设计新的MRI方法，这些方法更具特异性地描述活体组织的微观结构。其中一个例子是，目标是开发快速且易于实施的MRI方法，以基于白质松弛和扩散的详细间隔模型来可视化和量化大脑中的髓鞘含量。

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.