胆碱磷脂在维持细胞膜完整性、参与细胞代谢及信号转导方面起着重要作用。细胞膜胆碱磷脂成像不仅可以直观反映细胞膜状态，而且对研究细胞膜功能及相关疾病有重要意义，然而膜胆碱磷脂成像是磁共振成像的难点。本项目基于申请人前期研究发现的新的核间奥氏效应（NOE）信号，NOE(-1.6)，设计一种基于NOE技术的无创性、非标记胆碱磷脂磁共振成像新技术—胆碱磷脂质子转移成像。为实现该设想，本项目拟通过脉冲序列设计及NOE（-1.6）信号定量分析形成对胆碱磷脂的特异性成像，进而通过磷脂样本模拟实验和胆碱磷脂表达调控实验研究胆碱磷脂质子转移成像的机制，最后分别在细胞水平和模型动物水平评价该成像技术显示细胞膜损伤的能力。本项目提出的方法将为非标记细胞膜成像提供新思路，为研究细胞膜结构、功能及膜相关疾病提供新视角。

Choline phospholipids are important components of cell membranes, performing critical functions in cellular structure, metabolism, and signaling. Imaging of choline phospholipids plays a key role in studying cell membrane structures, functionalities and related diseases. However, the abilities of current MRI approaches for visualizing choline phospholipids remain very limited. Based on our previous findings that choline phospholipids induce a novel nuclear Overhauser effect (NOE) signal, NOE(-1.6), we plan to present a noninvasive label-free approach, termed choline phospholipid proton transfer (CPPT) imaging. In principle, CPPT is designed to image choline phospholipids based on magnetization transfer (MT) between restricted phospholipid choline head group and water at -1.6 ppm. We will design, optimize pulse sequences and develop quantitative methods for CPPT imaging with high specificity and sensitivity. Furthermore, we will probe the mechanisms of CPPT imaging using phantoms and transgenic cell models. In addition, we will study the ability of CPPT imaging in the detection of cell membrane injuries in cultured cells and in animal models. The proposed approach will open a new window for studying the molecular basis of cell membrane structures, functionalities and related diseases.