磁纳米增强的磁共振PRF测温方法及关键技术研究

活体内准确的温度成像是肿瘤热疗的关键难点之一，也是活体细胞/细胞团原位观测、研究的强有力工具，有助于医学基础研究的突破。磁学测温是目前最有前景的活体内测温方法之一，但是也面临着时空分辨率和信噪比双重瓶颈。为突破常规磁学测温的瓶颈，基于申请人磁纳米测温的研究基础，本项目引入具有优异温度敏感性的磁纳米粒子，进行磁纳米增强的磁共振PRF测温理论、方法及关键技术研究。主要创新：1）揭示磁纳米直流磁化和交流磁化的温度敏感机制和影响因素，阐明磁纳米测温机理；2）揭示温度通过磁纳米转换对磁共振PRF展宽、半高宽等的增强作用，建立磁纳米增强的磁共振PRF测温模型，提升其低场条件下的测温性能，探索活体内高性能磁学温度成像的可行性。磁纳米增强的磁共振PRF测温理论、方法及关键技术研究有望成为实现活体内高空间分辨率、高温度分辨率温度成像乃至我国高端热疗仪器切入的突破口，具有显著的科学意义与社会效应。

Accurate temperature imaging in vivo is one of the key difficulties in tumor hyperthermia, and it is also a powerful tool for in situ observation and research of living cells / cell clusters, which is helpful to the breakthrough of basic medical research. Magnetics-based thermometry is one of the most promising methods for in vivo thermometry, but it also faces the dual bottlenecks of spatial-temporal resolution and signal-to-noise ratio (SNR). In order to break through the bottleneck, based on the research foundation of magnetic nanoparticle (MNP)-based thermometry, this project introduces MNPs with excellent temperature sensitivity to study the theory, method and key technology of proton resonance frequency (PRF)-based magnetic resonance thermometry (MRT) enhanced by MNPs. The main innovations are as follows: 1) revealing the temperature sensitive mechanism and influencing factors of DC magnetization and AC magnetization of MNPs, and elucidating the temperature measurement mechanism of MNPs; 2) revealing the enhancement effect of temperature on the broadening and half maximum width of PRF through the conversion of MNPs, establishing PRF-based MRT model enhanced by MNPs, and improving its temperature measurement performance under low field conditions and exploring the feasibility of high performance magnetics-based temperature imaging in vivo. The research on the theory, method and key technology of PRF-based MRT enhanced by MNPs is expected to become the breakthrough to achieve high spatial resolution, high temperature resolution temperature imaging in vivo, and even the breakthrough of the high-end hyperthermia instruments in China, which has significant scientific significance and social effect.