IMAGE FORMATION AND RECONSTRUCTION APPROACHES USING PULSED ESR MICROSCOPY

这个子项目是利用资源的许多研究子项目之一。 由NIH/NCRR资助的中心拨款提供。对子项目的主要支持 子项目的首席调查员可能是由其他来源提供的， 包括美国国立卫生研究院的其他来源。为子项目列出的总成本可能 表示该子项目使用的中心基础设施的估计数量， 不是由NCRR赠款提供给次级项目或次级项目工作人员的直接资金。 顺磁剂在基于ESR的成像中用作示踪剂，在基于核磁共振的成像中用作造影剂，以获得它们在被成像对象中定位的信息。与核磁共振相比，使用顺磁探针作为示踪剂应用于成像感兴趣的对象进行成像具有固有的优势。无论是在微观水平上还是在活体成像实验中，基于ESR的成像的独特特征使得提取重要的功能信息成为可能，例如局部pO2、pH、粘度等实体，这些实体在MRI实验中无论在微观还是在宏观水平上都明显更困难甚至更具挑战性。随着最近获得的顺磁性物种，如三苯基自由基和固体探针，如LiPc，其光谱特性对于基于ESR的成像来说是最佳的，现在已经有可能在微观水平和动物水平上在细胞水平上询问：a)亚细胞变化，使用氧化还原响应性顺磁物种；b)亚细胞分布的氧分布，使用细胞可渗透的三叔丁基自由基和细胞内外的氧梯度，使用适当的同位素标记的自旋探针。ACERT将与NCI小组合作，检查活体实验中的生物样本，在体内实验中，小鼠受到特定器官的辐射暴露，剂量达到与辐射诱导的正常组织纤维化相关的病理表现，辐射后4-6周。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Paramagnetic agents are used both as tracers in ESR based imaging and as contrast agents in NMR based imaging to obtain information where they localize in the object being imaged. Imaging using paramagnetic probes applied as tracers in an object of interest in imaging has inherent advantages over NMR. The unique features in ESR based imaging either at a microscopic level or in an in vivo imaging experiment makes it possible to extract important functional information such as local pO2, pH, viscosity etc entities which are significantly more difficult and even challenging in an MRI experiment either at a microscopic or macroscopic level. With the recently available paramagnetic species such as the trityl radicals and solid probes such as LiPc whose spectral properties are optimal for ESR based imaging, it has now become possible at a microscopic level and at an animal level to interrogate at a cellular level: a) subcellular changes in gross redox status changes using redox responsive paramagnetic species; b) sub cellular profiles of oxygen distribution using cell permeable trityl radicals and intra- and extra cellular oxygen gradients using appropriately isotopically labeled spin probes. ACERT will work with the NCI group to examine biological samples from the in vivo experiments where mice receive exposure to radiation in specific organs to such doses that pathologies related to radiation-induced normal tissue fibrosis manifests 4-6 weeks post-radiation.