Rapid Scan Biomedical EPR Spectroscopy and Imaging

一种新的创新的电子顺磁共振(EPR)方法学将被开发用于体内 光谱学、成像和生物医学研究。工程师、研究科学家、临床医生 和业界建议设计和建造运行在250 MHz和L频段(约合 1.1 GHz)。重点是对光谱仪系统的仔细设计，包括磁铁、扫描 线圈、谐振器和数据采集优化体内生理EPR信号采集 光谱学和成像技术。快速扫描EPR包含磁场扫描的区域 相对于弛豫时间很快，这是一种新开发的介于连续波和脉冲之间的中间状态 EPR。直接探测快速扫描EPR信号直接提供了吸收线形，揭示了电子自旋 弛豫时间，不需要高入射功率，并提供准确的峰值相对幅度 快速衰减的信号。 具体目标是：(1)在L波段(约1.1千兆赫)建立一台具有扫描功能的专用快速扫描光谱仪 为生物医学、活体和成像实验优化的速率。(2)构建改进的谐振器，快速扫描 线圈和驱动器，以及250 MHz的专用快速扫描电桥。(3)搭建250 MHz快速扫描电桥， 谐振器和磁场扫描线圈单元，并安装在丹佛大学 芝加哥体内生理学成像中心，在那里它将被用来成像氧气浓度在 动物肿瘤。传统CW成像、脉冲EPR成像和快速扫描成像的优势 血氧测定仪和肿瘤学将进行比较。(4)设计、建造和测试硬件/软件系统 获取快扫描信号并对将在250 MHz上使用的光谱信息进行后处理 还有L乐队。除了活体成像，未来的应用还包括瞬时顺磁的研究 物种，如短寿命的自旋陷阱自由基，依赖时间的生物过程，以及 基本自旋弛豫现象。此工具是一种新的使能技术，将创建 活体测量氧气和顺磁物种科学研究的新时代，包括在 体内自由基。自由基与许多疾病有关，体内氧气的测量是 对癌症治疗、外周血管疾病和伤口愈合很重要。

A new and innovative electron paramagnetic resonance (EPR) methodology will be developed for in vivo spectroscopy, imaging and biomedical research. A partnership of engineers, research scientists, clinicians, and industry propose to design and build rapid-scan EPR systems operating at 250 MHz and at L-band (ca. 1.1 GHz). The emphasis is on careful engineering of the spectrometer systems, including magnet, scan coils, resonator, and data acquisition to optimize physiological EPR signal acquisition for in vivo spectroscopy and imaging. Rapid-scan EPR encompasses the regime in which the magnetic field sweep is fast relative to relaxation times, which is a newly developed intermediate regime between CW and pulsed EPR. Direct-detection rapid-scan EPR signals provide the absorption lineshape directly, reveal electron spin relaxation times without requiring high incident power, and provide accurate relative amplitudes of peaks in rapidly decaying signals. The Specific Aims are: (1) Build a dedicated rapid-scan spectrometer at L-band (ca. 1.1 GHz) with scan rates optimized for biomedical, in vivo, and imaging experiments. (2) Build improved resonators, rapid scan coils and drivers, and dedicated rapid-scan bridge at 250 MHz. (3) Build a 250 MHz rapid scan bridge, resonator, and magnetic field scan coil unit at the University of Denver and install it at the University of Chicago Center for In Vivo Imaging of Physiology, where it will be used to image oxygen concentrations in animal tumors. The benefits of traditional CW imaging, pulsed EPR imaging, and rapid-scan imaging for oximetry and oncology will be compared. (4) Design, build and test hardware/software systems for acquisition of the rapid-scan signal and post-processing of spectral information that will be used at 250 MHz and at L-band. In addition to in vivo imaging, future applications include the study of transient paramagnetic species, such as spin-trapped radicals with short lifetimes, time-dependent biological processes, and fundamental spin relaxation phenomena. This instrumentation is a new enabling technology and will create a new era for measuring oxygen in vivo and for scientific investigation of paramagnetic species, including in vivo free radicals. Free radicals are implicated in many diseases, and measurement of oxygen in vivo is important for cancer treatment, peripheral vascular disease, and wound healing.