摘要目的:探讨结缔组织疾病相关间质性肺病(CTD-ILD)患者新发肺癌的CT表现及动态变化特征。方法:收集58例CTD-ILD患者随访过程中的系列胸部CT图像，分析间质性肺病的CT特征、肺癌病灶CT图像上的初次出现时间、肺癌确诊时间，肺癌病灶的形态学特征(位置、形态、大小)及其CT动态变化特征。结果:58例患者中，类风湿关节炎患者最多(31例)。胸部CT表现为2种或2种以上肺间质纤维化CT征象并存。在随访过程中，共出现59个肺癌病灶，出现的中位时间为289 d，确诊时间晚于病灶出现43 d。其中44个病灶为非小细胞肺癌(其中鳞癌23个，腺癌19个)，12个病灶为小细胞肺癌。43个(72.9%)病灶位于肺下叶，41个(69.5%)病灶位于肺间质纤维化区域内。根据肺癌病灶CT形态特征可分为结节型(37例)、实变型(12)和蜂窝内型(10例)。结论:CTD-ILD患者的肺部CT表现复杂，新发肺癌在早期阶段常被漏诊或误诊，重视CTD-ILD的特殊影像学特点有助于新发肺癌的早期诊断。

abstractsObjective:To investigate the CT features and dynamic changes of new developed lung cancer in patients with connective tissue disease-related interstitial lung disease (CTD-ILD).Methods:A series of chest CT images of 58 CTD-ILD patients during follow-up were collected. The CT features of interstitial lung disease, the initial appearance time of lung cancer, the time of diagnosis of lung cancer, the morphological characteristics (location, shape, size) of lung cancer lesions and the dynamic changes of CT features were analyzed.Results:Among 58 patients, rheumatoid arthritis was the most common (31 cases). Chest CT images showed coexistence of two or more interstitial CT signs. During the follow-up, a total of 59 lung cancer lesions were found. The median time of lung cancer lesion occurred was 289 days. The median delay in diagnosis was 43 days. There were 44 cases of non-small cell lung cancer (including 23 cases of squamous cell carcinoma and 19 cases of adenocarcinoma), 12 cases of small cell lung cancer. Forty-three (72.9%) lesions were located in the lower lobes and 41 (69.5%) lesions were located in the area of pulmonary interstitial fibrosis. According to CT morphological characteristics of lung cancer, nodular type (37 cases), inflammatory consolidation (12 cases) and intra-honeycomb type (10 cases) were identified.Conclusions:The chest CT features of patients with CTD-ILD are complex. New developed lung cancer is easily missed or misdiagnosed in the early stage. Pay attention to the special CT characteristics of CTD-ILD with lung cancer is helpful for early diagnosis.