肺间质纤维化的发病机理:刺激(已知或未知)→肺泡炎→肺泡结构紊乱→肺泡毛细血管功能单位的丧失(终末期)。肺泡炎系指炎症与免疫效应细胞在肺泡的积聚。肺泡结构紊乱表现为肺实质细胞数量与形态的改变,以及肺间质纤维化,进一步发展则导致肺泡毛细血管功能单位的丧失。以上各阶段改变在同一患者肺部不同部位可同时存在。治疗的原则主要在于积极控制肺泡炎并使之逆转,进而防止发展为不可逆的肺纤维化。在成人肺组织,肺泡毛细血管功能单位一旦丧失,机体即无法加以补充。根据上述治疗原则,测定肺泡炎的程度对于确定与监测肺间质纤维化的治疗至关重要。近年文献报告,通过纤维支气管镜支气管肺泡灌洗与同位素稼(~(87)Ga)肺扫描检查,对于肺泡 Pathogenesis of Pulmonary Fibrosis: Stimulation (known or unknown) → Alveolitis → Alveolar structural disorders → loss of alveolar capillary functional units (terminal phase). Alveolitis refers to the accumulation of inflammation and immune effector cells in the alveoli. Alveolar structural disorder manifested as changes in the number and morphology of pulmonary parenchymal cells, and pulmonary interstitial fibrosis, further development leads to the loss of alveolar capillary functional units. The above stages of change in the same patient in different parts of the lung can exist. The main principle of treatment is to actively control alveolitis and make it reverse, thereby preventing the development of irreversible pulmonary fibrosis. In adult lung tissue, once the alveolar capillary function unit is lost, the body can not be supplemented. According to the above treatment principle, the determination of the degree of alveolitis is crucial for the identification and monitoring of the treatment of pulmonary fibrosis. In recent years, the literature reports that by bronchoscopic bronchoalveolar lavage and isotope Jia (~ (87) Ga) lung scan examination, for alveoli