Proton Electron Double Resonance Imaging (PEDRI) of Free Radicals

描述(由申请人提供)：这项建议是为了开发新的仪器，以便能够使用动态核极化(DNP)和质子电子双共振成像(PEDRI)快速测量和成像生物医学应用中的自由基。一种独特的变场、快速场循环(FC)Pedri仪器将被建造起来，能够执行从0到0.2T的场测量。DNP/Pedri可以提供活体动物中的自由基的快速高质量测量，这些新颖的双共振技术克服了EPR成像的一些基本限制，这些限制需要相对较长的图像数据收集时间，由于顺磁标记的固有线宽，提供的图像分辨率有限，并且需要非常大的梯度以及独立的解剖配准技术。因此，DNP和Pedri在生物医学系统中提供顺磁分子的灵敏、快速和高质量的测量和成像方面具有巨大的潜力。项目有5个目标：1)开发针对疾病小动物模型中自由基的Pedri进行优化的磁体、梯度、场控制和系统控制界面；2)开发DNP光谱和具有变场EPR预激的Pedri，用于基于核磁共振的自由基EPR谱检测和成像；3)开发场循环DNP和光谱空间Pedri，以提高测量灵敏度，最大限度地减少功率沉积和样品加热问题；4)开发针对体内和体外生物医学应用的DNP和Pedri的创新谐振器和射频设计；5)开发优化的软件和算法，使快速采集和分析DNP和Pedri光谱和图像数据成为可能。这些目标将共同克服射频功率沉积的现有限制，并导致开发出一种独特的变场快速场循环Pedri/DNP仪器，能够在疾病的小动物模型中快速、高质量地测量和成像自由基。这种新仪器和快速场循环、谐振器技术和超快图像采集方面的相关创新，有可能使自由基检测的灵敏度提高100倍，图像分辨率提高10倍，图像采集速度比以前的固定场Pedri仪器快10倍，同时将射频功率沉积减少两个数量级以上。

DESCRIPTION (provided by applicant): This proposal is for development of novel instrumentation to enable rapid measurement and imaging of free radicals in biomedical applications using Dynamic Nuclear Polarization (DNP) and Proton Electron Double Resonance Imaging (PEDRI). A unique variable field, rapid field cycling (FC) PEDRI instrument will be built capable of performing measurements from fields of 0 to 0.2 T. DNP/PEDRI can provide rapid high quality measurements of free radicals in living animals and these novel dual resonance techniques overcome a number of the fundamental limitations of EPR imaging that requires relatively long times for image data collection, provides limited image resolution due to the inherently broad linewidths of paramagnetic labels, and needs very large gradients as well as independent techniques for anatomic registration. Therefore, DNP and PEDRI have great potential to advance this field providing: sensitive, rapid and high quality measurements and imaging of paramagnetic molecules in biomedical systems. There are 5 aims: 1) Development of a magnet, gradient, field control, and system control interface optimized for PEDRI of free radicals in small animal models of disease; 2) Development of DNP spectroscopy and PEDRI with variable field EPR preexcitation for NMR based detection and imaging of the EPR spectra of free radicals; 3) Development of Field Cycled DNP and Spectral-Spatial PEDRI to enhance measurement sensitivity and minimize problems with power deposition and sample heating; 4) Development of innovative resonator and RF design optimized for DNP and PEDRI of in vivo and ex vivo biomedical applications; 5) Development of optimized software and algorithms enabling rapid acquisition and analysis of DNP and PEDRI spectral and image data. Together these aims will overcome existing limitations of RF power deposition and result in the development of a unique variable field rapid field cycling PEDRI/DNP instrument capable of rapid, high quality measurement and imaging of free radicals in small animal models of disease. This new instrumentation and related innovations in rapid field cycling, resonator technology and ultra fast image acquisition, have the potential to provide 100-fold enhanced sensitivity in radical detection, with 10-fold higher image resolution and over 10-fold faster image acquisition than prior fixed field PEDRI instrumentation, while reducing RF power deposition by over two orders of magnitude.