乏氧是肿瘤微环境最普遍存在的现象。它与肿瘤发生发展关系密切，且影响放化疗的疗效。然而目前尚无有效无创敏感的评价肿瘤乏氧的理想方法。前期工作发现：游离氧有顺磁性，吸入纯氧后脑组织信号明显变化，正常和异常血供区的信号有显著差异。本研究计划以胶质瘤为例，分组建立乏氧、正常及富氧的三组u251细胞系大鼠胶质瘤模型；成瘤后利用纯氧吸入法增加不同供氧区肿瘤组织的游离氧含量差异，同时用BOLD-fMRI显示（称"游离氧功能磁共振成像"）。fMRI结果将与PET/CT乏氧显像、氧电极法结果比较，不断优化成像方法。用免疫组化检测及比较三组胶质瘤HIF-1α、VEGF、CXCL12/CXCR4及CXCR7的表达，并讨论与游离氧显像及肿瘤血流动力学参数的相关性，从机制上深化成像原理。研究最终目的在于建立肿瘤乏氧影像学评价新方法。这对于认识肿瘤发病机制、临床判断肿瘤乏氧及指导个体化治疗和判断预后均意义深远。

The tumors' hypoxia microenvironment is characteristic and generally seen.Hypoxia microenvironment plays a crucial role in malignant progression and restricts curative efficacy.However, the existing modalities are far from effective in evaluating the hypoxia in tumor.Our preliminary research has revealed that: free oxygen is paramagnetic and the signal of brain tissue changes significantly after inhalation of pure oxygen. Prominent signal difference has been detected between areas with differed perfusion levels. As an example of tumor with hypoxia, the current research is planning to establish glioma model (originated from u251 glioma cell lines) of rats, which are then seperately developping to be hyperoxia, normal and hypoxia groups.Oxygen enhanced BOLD-magnetic resonance imaging is to be performed during paradigm of pure oxygen inhalation. The results of BOLD-fMRI are to be compared to those form PET/CT imaging and oxygen electrode evaluation (reference standard). The HIF-1、VEGF、CXCL12/CXCR4、CXCL12/CXCR7 levels in three group would be detected and compared with immunohistochemistry, whose correlation with the results of fMRI and hemodynamics reveals the molecular-level basis of oxygen-enhanced BOLD-fMRI. The results will be introduce and extend to most types of tumor and other disease condition, such as ischemia and infarction. The aim of the research is to establish and optimize the oxygen related BOLD-fRMI to better demonstrate hypoxia microenvironment in tumor.The results could be extend to most types of tumor and other disease condition, such as ischemia and infarction.