我国是吸烟大国，吸烟与慢阻肺和肺癌等肺部疾病的发生发展紧密相关。目前临床的诊断技术如CT和肺功能测试，难以对小气道、肺泡等微结构参数和肺组织的代谢功能进行定量探测，因此，吸烟所致肺损伤的早期诊断和临床干预非常困难。申请人前期利用超极化129Xe的MRI新技术，测量了129Xe气体在大鼠肺部的表观扩散系数(ADC)，发现吸烟模型大鼠与健康大鼠的ADC值具有显著性差异，且ADC值与离体肺部组织学结果存在相关性。在此基础上，本项目拟基于一体化PET/MRI，发展超极化129Xe多b值扩散MRI技术，联合葡萄糖代谢显像，对不同吸烟时长模型大鼠的肺部微结构和代谢动力学功能进行同步多参数定量分析，以期建立一种评估吸烟引起肺损伤的灵敏、无创、可视化的早期评估新方法，探索吸烟导致肺部微结构和代谢功能的动态变化，为临床早期干预吸烟导致的肺损伤提供基础。

China is a big smoking country, and smoking is closely related with the occurrence and development of lung diseases such as chronic obstructive pulmonary disease (COPD) and lung cancer. At present, the clinical diagnostic techniques such as CT and pulmonary function tests are very difficult to quantitatively detect microstructural parameters of such as small airways and alveoli, and metabolic functions of lung tissues. Therefore, early diagnosis and clinical intervention for lung injury caused by smoking is very difficult. The applicant previously used the new MRI technology of hyperpolarized 129Xe to measure the apparent diffusion coefficients (ADCs) of 129Xe gas in the lung of rats. It was found that the ADCs were significantly different between the smoking rats and healthy rats, correlated with the histology results in vitro. On the basis, the project is to develop hyperpolarized 129Xe multi-b diffusion MRI technology, combined with glucose metabolism imaging based on the integrated PET/MRI, which is used to detect the lung microstructures and metabolic dynamics in rat model of different smoking durations with multi-parameters quantitative analysis. The targets are to establish a new method for early sensitive, non-invasive and visual assessment of smoking-induced lung injury, which can be used to explore the pulmonary changes about both microstructure and metabolic function, and finally provide the basis for early clinical intervention for lung injury caused by smoking.