肺血管炎的临床与影像学特点解析

肺部血管炎包括原发性与继发性两大类.继发性血管炎包括感染性疾病、结缔组织病、恶性肿瘤和过敏性疾病所致肺血管炎.原发性血管炎的分类通常根据受累血管的大小分为大血管炎、中血管炎和小血管炎.肺部血管受累常见于原发性大血管炎[大动脉炎(Takayasu arteritis),巨细胞动脉炎(giant cell arteritis,GCA),白塞病(Behcetdisease)]和原发性抗中性粒细胞胞浆抗体(anti-neutrophil cytoplasmic antibody,ANCA)相关性小血管炎[肉芽肿性多血管炎(granulomatosis with polyangiitis,GPA),显微镜下多血管炎(microscopic polyangiitis),嗜酸性肉芽肿性多血管炎(eosinophilic granulomatosis with polyangiitis,EGPA)].原发性肺血管炎的影像学表现极具多样性,包括血管壁增厚、结节影、空洞、磨玻璃影和实变影等.原发性肺部小血管炎常导致弥漫性肺泡出血(diffuse alveolar hemorrhage,DAH).相比于胸片,胸部CT更能够显示肺血管炎的病变特征和侵及范围.肺部血管炎的诊断极具挑战性,需要通过患者的临床特征、影像学特点、实验室检查结果和组织病理学特征作出综合判断.

Clinical and imaging features of pulmonary vasculitis

Pulmonary vasculitis includes two types:primary vasculitis and secondary vasculitis. Secondary pulmonary vasculitis consists of infectious diseases,connective tissue diseases,malignant tumor and allergic diseases.Primary pulmonary vasculitis is usually classified into large,middle and small vessel vasculitis according to the size of the involved vessels.Pulmonary vascular involvement is common in primary large vessel vasculitis,including Takayasu arteritis,giant cell arteritis (GCA) and Behcet's disease,and primary anti-neutrophil cytoplasmic antibody (ANCA) associated vasculitis,including granulomatosis with polyangiitis(GPA),microscopic polyangiitis(MPA)and eosinophilic granulomatosis with polyangiitis(EGPA).The image findings of primary pulmonary vasculitis are very diverse,including thickening of the vascular wall,nodular shadows,cavity,ground glass opacity and consolidation.Primary pulmonary vasculitis often leads to diffuse alveolar hemorrhage (DAH).Compared with the chest radiograph,chest computer tomography(CT)is more capable of showing the characteristics and extent of pulmonary vasculitis.The diagnosis of pulmonary vasculitis is very challenging.It is necessary to make a comprehensive judgment by the clinical features,imaging characteristics,laboratory findings and histopathological features.