Magnetic Resonance Imaging with Laser-Polarized He-3 and Xe-129 of Biological and Non-Biological Systems Using High Power Diode Lasers

使用高功率二极管激光器对生物和非生物系统进行激光偏振 He-3 和 Xe-129 磁共振成像

• 批准号: 9612244
• 负责人: William Happer
• 金额: $ 93万
• 依托单位: Princeton University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-09-15 至 2000-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9612244&HistoricalAwards=false
• 关键词: Magnetic; Resonance; Imaging; Laser; Polarized

9612244 Happer The PIs describe an interdisciplinary program to investigate a revolutionary new technology employing laser-polarized gases for greatly enhancing the magnetic resonance images (MRI) of biological cavities such as lungs and sinuses, as well as nonbiological systems which as voids in ceramics, etc. This technique was recently used to obtain the first MRI images of the gas space of a human lung by a collaboration between researchers at Princeton and Duke Universities. The method uses advances in optical spin polarization made possible through the understanding of spin exchange interactions between alkalimetal atoms and noble gas nuclei developed at Princeton. To make this a practical, low cost and widely applied technique for imaging both biological and non-biological systems, significant improvements in our understanding of the physics of optical spin polarization, as well as in the high power laser diodes necessary to accomplish this task are needed. In this project, researchers at Princeton and the University of Wisconsin will concentrate on the demonstration of very high power, low cost, long-lifetime Al-free diode laser arrays with linewidths sufficiently narrow to efficiently polarize He-3 and Xe-129 for a wide range of MRI applications. The laser development includes fabrication of novel MQW structures with improved carrier confinement, as well as distributed Bragg reflector and external cavity structures to achieve narrow linewidths, will build on existing strengths at both Princeton and UW-Madison in high power laser diodes. To improve the MRI technique, the PIs will explore the possibility of imaging laser polarized gases dissolved in blood and other liquids. Methods for increasing the efficiency of the spinexchange process, and for accumulating large quantities of spinpolarized gases will be investigated. ***

PIs描述了一个跨学科的项目，旨在研究一项革命性的新技术，该技术采用激光极化气体来大大增强生物腔（如肺和鼻窦）以及非生物系统（如陶瓷中的空隙）的磁共振图像（MRI）。这项技术最近被普林斯顿大学和杜克大学的研究人员合作用于获得人类肺部气体空间的第一张MRI图像。该方法利用了光学自旋极化的进展，通过对碱金属原子和惰性气体原子核之间自旋交换相互作用的理解，使之成为可能。为了使其成为一种实用的、低成本的、广泛应用于生物和非生物系统成像的技术，我们需要在光学自旋极化的物理理解以及完成这项任务所需的高功率激光二极管方面取得重大进展。在这个项目中，普林斯顿大学和威斯康星大学的研究人员将专注于展示高功率、低成本、长寿命的无铝二极管激光阵列，其线宽足够窄，可以有效地极化He-3和氙-129，用于广泛的MRI应用。激光器的开发包括制造具有改进载流子约束的新型MQW结构，以及分布式Bragg反射器和外部腔结构，以实现窄线宽，将建立在普林斯顿大学和威斯康星大学麦迪逊分校在高功率激光二极管方面的现有优势之上。为了改进MRI技术，pi将探索对溶解在血液和其他液体中的激光极化气体进行成像的可能性。将研究提高自旋交换过程效率和积累大量自旋极化气体的方法。＊＊＊