高级别胶质瘤复发或进展的比率较高。由放射治疗导致的放射性脑损伤发病率日益上升，由于其临床表型及影像学表现多样，导致其在可逆性病理阶段的诊断被延误或与胶质瘤复发征象混淆。多模态分子影像可以整合解剖及功能影像信息，定量反映肿瘤的分子表型及生物学特征等，为胶质瘤及放射性脑损伤的精准诊疗提供新的研究思路。本研究内容如下：（1）建立胶质瘤复发及不同阶段放射性脑损伤动物模型并进行脑部11C-MET及18F-Alfatide Ⅱ双探针动态PET/MR多模态显像。（2）探讨放射性脑损伤不同阶段模型的PET/MR多模态分子显像与氨基酸代谢水平及新生血管的相关性。（3）挖掘整合PET/MR多参数对相关分子生物标志物的差异化表达，构建基于11C-MET及18F-Alfatide Ⅱ PET/MR多模态显像对胶质瘤复发及不同阶段放射性脑损伤鉴别诊断的决策树模型并在体验证完善模型。

At present, surgical excision combined with concurrent radiotherapy and chemotherapy are commonly used in the treatment of high-grade glioma, but the rate of recurrence or progression is high. The incidence of radiation-induced brain injury caused by radiation therapy is increasing, and its diagnosis in the reversible pathological stage is delayed due to its clinical phenotype and imaging manifestations. At the same time, radiation-induced brain injury is easily confused with the glioma recurrence, delaying the early diagnosis and treatment of glioma recurrence. Multi- modality molecular imaging can integrate anatomical and functional image information, quantitatively reflect the molecular phenotype and biological characteristics of tumors, and provide new ideas for the accurate diagnosis and treatment of glioma and radiation-induced brain injury. The content of this study is as follows: (1) Establishing the animal models of glioma recurrence and radiation-induced brain injury at different stages and performing dynamic 11C-MET and 18F-Alfatide Ⅱ PET/MR examination and data acquisition; (2) Analyzing the correlations between the dynamic changes of PET/MR imaging with the metabolic level of amino acid，and with the neovascularization status at different stages of radiation-induced brain injury model; (3) Excavation and integration of PET/MR multi-parameters to differentiated express the relevant molecular biomarkers； Constructing the decision tree model based on multiple parameters with PET/MR for differential diagnosis with glioma recurrence and radiation-induced brain injury at different stages, then verify and improve the model in vivo.