结构性及病理性改变共同构成肝肿瘤影像学检查的基础，PET/MR多模态显像则可以在多方面提供有效信息。病灶酸碱微环境改变是早期癌变的重要标志，但是无创检测较困难。本课题研究基于Gd-HPDO3A@Liposome-Ga-68的PET/MR用于肝肿瘤增强显像及酸碱微环境检测的可行性，并探讨其在肝癌早期诊断中的价值。研究以二乙基亚硝胺诱导原位肝癌为模型，于PET/MR一体机行T1、T2、LipoCEST及PET显像，并与解剖结构改变及有创pH值检查对照来验证影像学发现的准确性及时效性。Ga-68 PET在对肝摄取功能精确分析的同时为CEST信号提供浓度定量依据，解决CEST 显像剂在体内定量难的问题。本研究目的在于解决传统影像学检查信息单一，干扰因素多等问题。重点探查该分子影像技术在肝癌早期诊断中的价值，同时为LipoCEST临床转化提供新思路。

Structral and pathological changes forms the foundations of tumor imaging, and PET/MR can potentially provide the comprehensive information on diagnosis. The changes of pH microenviroment is a sign of liver cancerization, but the noninvasive detection is hard to perform. This research aims to detect the feasibility of measuring lesional microenvironment and evaluate the effectiveness of early diagnosis of liver cancer based on Gd-HPDO3A@Liposome-Ga-68 PET/MR. The in situ liver cancer model is induced by intrapetritoneal injection of nitrosamine.T1, T2, LipoCEST and Ga-68 PET scans willl be performed via PET/MR to test the diagnosis accuracy and timeliness. Ga-68 imging data provide a reference for in vivo quantification of CEST agent, overcoming the limitation for in vivo application of LipoCEST agents. This research can help to enrich the clinical information from multimodal imaging. On the other side, this research focus on exploring the value of PET/MR in the early detection of liver cancer, meanwhile, the preliminary results are referable for clinical translation of paraCEST-MRI.