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通过磁共振成像(MRI)对组织进行定量表征的新方法。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。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，试图提取关于从中衍生出它们的微解剖水室的特定信息。获得和分析亚体素特征的新的、有效的方法的进一步发展和应用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此类研究开发新的方法，并对正常和病理条件下白质和肌肉的MRI对比的生物学基础提供更完整的理解。对模型组织的实验研究将建立关于水扩散、纵向和横向松弛、磁化传递以及它们如何相互关联以及从中衍生出的物理隔间的全面和定量的活体描述。这些观察结果可以用来设计新的磁共振成像方法，这些方法更具特异性地描述组织的微观结构。其中一个例子是，目的是开发高效和有效的磁共振方法，根据脑白质的详细隔间模型，可视化和量化大脑中的髓鞘含量。公共卫生相关性：MRI是一种广泛使用的诊断成像方式，能够相对非侵入性地显示软组织。磁共振成像中的对比度是由于体内水分子之间的许多复杂相互作用及其局部环境的物理和化学特征造成的。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.