Proton Magnetic Resonance of Biological Systems

核磁共振（NMR）以其对结构和动力学的综合敏感性，是一种研究生物系统的成熟技术。由于生命过程是在溶液中发生的，这些体系中水的质子核磁共振应该包含重要的信息。事实上，医学磁共振成像（MRI）依赖于不同类型的正常组织之间以及正常组织和病理组织之间的组织水信号差异所提供的精细对比。然而，我们对这种精妙的MR对比的根本起源的理解仍处于原始阶段。***目前我们的研究主要集中在人类的大脑和脊柱组织以及人类组织的动物模型。我们的研究计划有三个主要主题：1)探索磁共振（MR）信号（或MRI对比）性质的基本机制。2)开发和优化磁共振技术，利用基本机制创造独特的对比；3)应用这些磁共振技术更好地了解正常和异常的人体组织结构和功能。***在过去的二十年里，我们的研究小组一直致力于通过MRI无创测量髓磷脂含量。我们率先在体内测量髓磷脂水分数（髓磷脂水的信号），这有望提供准确的髓磷脂在体内磁共振测量。髓磷脂是大脑中隔离神经元的物质，它能使神经信号传导速度加快两个数量级，一旦髓磷脂受损，就会出现临床缺陷。髓磷脂在大脑的工作中起着重要的作用，因此，许多研究一直致力于寻找人类体内髓磷脂成像技术。****这项NSERC发现资助研究计划的目标：***1)通过描述基本机制，特别是磁化交换的作用，更好地理解髓鞘水成像。***2)探索其他磁共振技术（mcDESPOT和非均匀MT）在体内测量髓磷脂的机制***3)通过减少扫描时间和增加信噪比来进一步优化髓磷脂水成像技术***4)进一步了解髓磷脂在正常脑和脊柱功能中的作用***研究将在两个地点进行：UBC物理，我们将使用核磁共振光谱仪来研究离体牛（牛）的大脑和大脑模型的样本；以及UBC放射学，我们将研究正常人的大脑和脊柱。这项研究将改进用于测量脑和脊柱髓鞘形成的MRI技术。准确测量髓磷脂的能力将使评估旨在保护大脑免受脱髓鞘或诱导异常大脑再髓鞘的药物的功效成为可能。它还将有助于描述髓鞘形成在正常大脑和许多神经系统疾病（如多发性硬化症）中的作用。**

Nuclear magnetic resonance (NMR), with its combined sensitivity to both structure and dynamics, is a well-proven technique for the study of biological systems. Since life processes occur in solution, the proton NMR of water in these systems should contain important information. Indeed, medical magnetic resonance imaging (MRI) relies on the exquisite contrast provided by differences in signal from tissue water between different types of normal tissue and between normal and pathological tissue. However, our understanding of the fundamental origins of this exquisite MR contrast is still at a primitive stage.***At present our research is focused on brain and spine tissue in humans and animal models of human tissue. Our research program has three main themes: 1) exploring the fundamental mechanisms responsible for the nature of the magnetic resonance (MR) signal (or MRI contrast). 2) developing and optimising MR techniques which exploit the fundamental mechanisms to create unique contrasts and 3) application of these MR techniques to better understand normal and abnormal human tissue structure and function. ***For the past two decades, our research group has worked on the measurement of myelin content non invasively by MRI. We pioneered the in vivo measurement of the myelin water fraction (the faction of signal from myelin water) which promises to provide an accurate in vivo MR measure of myelin. Myelin, which insulates neurons in brain, accelerates nerve signal conduction rates by two orders of magnitude and when myelin is damaged there are clinical deficits. Myelin plays a large role in how the brain works, consequently, much research has been dedicated to finding techniques for imaging myelin in humans in vivo.****OBJECTIVES of this NSERC Discovery Grant Research Program: ***1) To better understand myelin water imaging by characterising the fundamental mechanisms, particular the role of magnetization exchange. ***2) To explore the mechanisms behind other magnetic resonance techniques which have been proposed to measure myelin in vivo - mcDESPOT and inhomogeneous MT. ***3) To further optimise the myelin water imaging technique by reducing scan time and increasing signal to noise***4) To further understand the role of myelination in normal brain and spine function ***The research will be carried out in two locations: UBC Physics where we shall use a NMR spectrometer to study ex vivo bovine (cow) brain and samples which model brain; and UBC Radiology where we shall study normal human brain and spine. ***This research will result in improvements to MRI techniques for measuring brain and spine myelination. The ability to measure myelin accurately will enable assessment of the efficacy of drugs designed to protect the brain from demyelination or to induce remyelination in abnormal brain. It will also aid in characterizing the role of myelination in normal brain and many neurological diseases, for example, multiple sclerosis. **