Electron spin resonance imaging: a functional imaging tool for biomedical science

电子自旋共振成像：生物医学的功能成像工具

• 批准号: BB/E005322/1
• 负责人: Daniel Wolverson
• 金额: $ 92.26万
• 依托单位: University of Bath
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2006
• 资助国家: 英国
• 起止时间: 2006 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FE005322%2F1
• 关键词: Electron; spin; resonance; imaging; functional

Modern medicine relies upon a variety of body scanners with which to visualise the internal structures of our bodies. Similar instruments are used by research scientists to study materials of significance across the whole range of the biological and medical sciences. For many purposes, however, anatomical or other structural information is not enough: we seek functional imaging methods that report on the processes that are taking place. Our project is concerned with the development of such a functional imaging method of exceptionally broad applicability: electron spin resonance imaging. It is the electrons furthest away from the atomic nucleus, the so-call 'valence' electrons, which confer most of the chemical and physical properties on atoms, ions, molecules and materials, since it is these electrons that interact most strongly with the environment. When an odd number of valence electrons are present (or in some special cases an even number) the electrons impart a net magnetic moment onto the atom/molecule/material. Electron spin resonance is a sensitive and precise method of measuring this magnetism. It is possible to relate these measurements to the environment of the valence electrons and hence use it to report on chemical structure and dynamics, and ultimately to provide functional information on chemical and other dynamical processes. Electron spin resonance determines the magnetic properties of electrons by measuring the applied magnetic field that is required to allow resonant absorption of microwave radiation. Spatial information is obtained by applying different magnetic fields to different parts of the object under investigation. If the microwave absorption is measured in a large number of magnetic field gradients a three-dimensional image of the magnetic properties of the object can be calculated. This overall approach is similar to that employed in nuclear magnetic resonance imaging (MRI). However, electron spin resonance imaging is technically much more challenging because valence electrons interact much more strongly with their environment than do nuclei. This important difference means that new, extremely sensitive and efficient, methods of measuring microwave absorption are required. Our project is focused on the necessary technologies. The sensitivity of an electron spin resonance imaging instrument should properly be expressed as the number of electrons that can be detected in a spatially resolved volume element in a given time. Thus an instrument with substantially improved sensitivity will also be able to make higher resolution images and/or faster measurements. Insufficient resolution and speed have been limiting factors in earlier approaches. The motivation behind our project is the extraordinary range of important applications to which ESR imaging can potentially be put. This work will enable substantial advances in our understanding of major human diseases such as cardio-vascular disease, cancer, diabetes, and septic shock, and also allow the efficacy of new therapies for these conditions to be assessed.

现代医学依赖于各种身体扫描仪来可视化我们身体的内部结构。研究科学家使用类似的工具来研究整个生物学和医学科学范围内具有重要意义的材料。但是，出于许多目的，解剖学或其他结构信息是不够的：我们寻求有关正在发生的过程报告的功能成像方法。我们的项目涉及这种功能成像的发展方法，具有异常广泛的适用性：电子自旋共振成像。它是远离原子核的电子，即所谓的“价”电子，它赋予原子，离子，分子和材料的大多数化学和物理性能，因为这些电子与环境最强烈相互作用。当存在奇数的价电子（或在某些特殊情况下），电子将净磁矩赋予原子/分子/材料。电子自旋共振是一种测量这种磁性的敏感而精确的方法。可以将这些测量值与价电子的环境联系起来，从而将其报告有关化学结构和动力学的报告，并最终提供有关化学和其他动态过程的功能信息。电子自旋谐振通过测量允许微波辐射吸收所需的施加磁场来确定电子的磁性。空间信息是通过将不同的磁场应用于正在研究的对象的不同部分中获得的。如果在大量磁场梯度中测量微波吸收，则可以计算物体的磁性特性的三维图像。这种总体方法类似于核磁共振成像（MRI）中使用的方法。但是，电子自旋共振成像在技术上更具挑战性，因为价电子与环境的相互作用要比核更强烈。这种重要的差异意味着需要新的，极其敏感和高效的测量微波吸收的方法。我们的项目专注于必要的技术。电子自旋共振成像仪器的灵敏度应适当地表示为在给定时间内可以在空间分辨的体积元件中检测到的电子数。因此，具有大大提高灵敏度的仪器也将能够进行更高的分辨率图像和/或更快的测量。在早期方法中，分辨率和速度不足一直是限制因素。我们项目背后的动机是可以将ESR成像推出的重要应用程序范围。这项工作将使我们对主要人类疾病（例如心血管疾病，癌症，糖尿病和败血性休克）等主要人类疾病的理解有了重大的进步，还允许对这些疾病的新疗法有效。