目的: 探索分析 ¹⁸F-脱氧葡萄糖正电子发射断层显像/计算机体层扫描技术(¹⁸F-flurodeoxyglucose positron emission tomography/computed tomography, ¹⁸F-FDG PET/CT)在风湿免疫病中的应用现状。方法: 纳入2012年1月至2018年12月期间于北京大学人民医院风湿免疫科住院并进行 ¹⁸F-FDG PET/CT检查的患者，回顾性分析 ¹⁸F-FDG PET/CT检查技术在风湿免疫病中的临床应用情况及其影像学特征。结果: 共486例风湿免疫科的住院患者行 ¹⁸F-FDG PET/CT检查，占全院行PET/CT检查总例数的5.30%，其中女性304例(62.55%)，男性182例(37.45%)，男女比例为1 ∶1.67，平均年龄(53.21±18.81)岁，45~65岁年龄段患者的比例(227/486，46.71%)最高。风湿免疫科患者行PET/CT检查的主要目的依次为排除肿瘤(55.56%)、协助明确诊断(24.60%)及评估病情(19.84%)。74例患者的PET/CT检查结果提示恶性肿瘤，327例患者提示风湿免疫病，其中292例对疾病的提示诊断具有参考作用，25例患者提示感染性疾病，60例患者的检查结果无明确提示意义。有10例风湿免疫病患者在治疗后复查PET/CT进行了随访，缓解病例的检查结果显示，¹⁸F-FDG代谢活性降低以及代谢增高病灶的范围缩小。结论: ¹⁸F-FDG PET/CT在风湿免疫病中的应用日益广泛，尤其在排除恶性肿瘤方面具有重要价值，同时对疑难病例的辅助诊断具有一定参考作用。

Objective: To explore the application of ¹⁸F-flurodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) in rheumatic diseases, to compare these different imaging features, and to describe the current PET/CT imaging status in clinical practice. Methods: A total of 486 cases in our department from January 2012 to December 2018 were enrolled in this study, and ¹⁸F-FDG PET/CT examination was performed in all the patients. The clinical use of ¹⁸F-FDG PET/CT was retrospectively analyzed to discuss the clinical application and its imaging characteristics of rheumatic diseases. Categorical data were used to ascertain prevalence statistics, whereas continuous data were used to delineate means and standard deviations. Independent sample t test, Chi square test and Mann-Whitney U test were used for statistical analysis. A P-value of < 0.05 was considered significant. Results: (1) From 2012 to 2018, totally 486 patients in the Department of Rheumatology and Immunology underwent ¹⁸F-FDG PET/CT examination, accounting for 5.30% of the total number of PET/CT examinations in the whole hospital. In this study, 304 of the 486 patient were female (62.55%), 182 of them were male (37.45%), the average age of the patients was (53.21±18.81) years, and the proportion of the patients aged 45-65 (227/486, 46.71%) was the highest group. (2) Three leading purposes of the PET/CT examination in our department were to exclude cancers (55.56%), assist in diagnosis (24.60%) and evaluate the disease activity (19.84%). (3) Of the 486 patients who underwent ¹⁸F-FDG PET/CT, 327 cases might indicate a differential diagnosis of rheumatic disease, of which, 292 cases were highly suggestive of diagnosis, including 61 cases of myositis, 60 cases of vasculitis, 37 cases of adult still's disease, 32 cases of IgG4 related diseases, 30 cases of rheumatoid arthritis, 22 cases of Sjögren's syndrome, 22 cases of systemic lupus erythematosus, and 9 cases of rheumatic polymyalgia; the remaining 35 cases only prompted the possibility of autoimmune disease. Of the 486 patients, 74 cases suggested the diagnosis of cancers, 25 cases indicated the diagnosis of infectious diseases, while 60 cases could not show any diagnostic values. Ten patients with rheumatic disease were followed up with a post-treatment repeat PET/CT, and the findings in remission showed reduced ¹⁸F-FDG metabolic activity as well as a reduction in the extent of metabolic hypertrophic lesions. Conclusion: There are some typical sign of ¹⁸F-FDG PET/CT for diffuse connective tissue diseases, therefore ¹⁸F-FDG PET/CT has auxi-liary effect on the classification diagnosis of rheumatic diseases, especially for the exclusion of cancers.