Time Domian Electron Paramagnetic Resonance Imaging

项目1：时间域电子顺磁共振成像：摘要：a)仪器：我们已经开发了仪器，以使用“时锁子采样”策略的数据采集模式。这种模式使用低速数据采集(20-100 MHz)来采样高速瞬变数据，而不会损失信号质量的完整性。这种方式的优点是可以利用具有更好动态范围的低成本信号平均器进行成像。具体地说，在成像实验中，图像强度的动态范围将得到显著改善，因此即使在存在高强度区域的情况下，也可以有效地表示低强度像素。b)数字EPR成像光谱仪：到目前为止，EPR成像仪器使用的是使用模拟模块的光谱仪。随着最近数字信号处理技术(DSP)的出现，我们已经开始实施数字版的EPR成像光谱仪。这项工作的具体优点是显著减少了图像数据收集/重建的时间，并消除了与模拟组件相关的噪声影响。我们完成了一个测试平台，并成功实现了一个基于DSP的EPR成像光谱仪。c)图形用户界面：由于EPR成像光谱仪是NIH建造的研究光谱仪；扫描仪的操作相当复杂，而且不熟悉仪器的用户也可能损坏。由于大多数活体实验都是由实验室成员进行的，对仪器的经验很少，我们开发了一个图形用户界面(GUI)，使扫描仪的操作变得用户友好，以及一个用于图像重建和显示的附加界面。

Project 1: Time Domian Electron Paramagnetic Resonance Imaging:Summary:a) Instrumentation: We have developed instrumentation to with data acquisition modalities utilizing "Time-locked sub sampling" strategies. This modality uses low speed data acquisition ( 20 - 100 MHz) to sample high-speed transient data without loss of integrity of the signal quality. The advantage of this modality is that low-cost signal averagers with better dynamic range can be utilized in imaging. Specifically, in imaging experiments, the dynamic range of the image intensity will be significantly improved so that low intensity pixels will be validly represented even in the presence of high intensity regions.b) Digital EPR imaging spectrometer: Until now the EPR imaging instrumentation utilized spectrometers using analog modules. With the recent availability of digital signal processing technology (DSP), we have initiated the implementation of digital version of the EPR Imaging spectrometer. The specific advantages of this effort are that significant reduction in time of image data collection/reconstruction as well as elimination of noise contributions associated with analog components. We completed a test platform and successfully implemented a DSP based EPR imaging spectrometer.c) Graphic User Interface: Since the EPR Imaging spectrometer is an NIH built research spectrometer; the operation of the scanner is fairly complicated and also can be damaged by users unfamiliar with instrumentation. Since most in vivo experiments are carried out by members of the lab with minimal experience with instrumentation, we have developed a graphics user interface (GUI) to make the operation of the scanner for data collection user friendly as well as an additional interface for image reconstruction and display.