胸部CT表现为反晕征五例并文献复习

Reversed halo sign： chest CT findings in 5 patients and cause analysis

目的 探讨反晕征在不同肺部疾病谱的分布,提高对这一影像征的认识.方法 报道北京大学第三医院收治的胸部CT表现为反晕征的5例患者,并以“反晕征、仙女环、环礁征”为检索词,通过万方数据库、中国知网和中国期刊全文数据库（CNKI）共检索出中文文献8篇;以“reversedhalo sign,fairy ring,atoll sign”为检索词,通过PubMed数据库检索出外文文献102篇.对文献中的420例以及本文中的5例患者进行分析.结果 本文5例患者均为男性,年龄19～55岁.原发病分别为隐源性机化性肺炎、肺结核、肺梗死、肺水肿和支原体肺炎.结合既往文献报道,反晕征见于肺部感染性疾病共206例,绝大多数（96％）为真菌感染（119例）和MTB感染（79例）,毛霉感染（59例）比曲霉更常见（27例）.反晕征见于非感染性疾病共219例,最常见为机化性肺炎,包括隐源性机化性肺炎和继发性机化性肺炎（145例,66％）,还可见于肺癌、结节病、其他病理类型的间质性肺病、肺梗死和肺水肿等.反晕征在真菌感染、肺结核和机化性肺炎中的影像形态有所不同.此外,本文中支原体肺炎所致的反晕征为首次报道.结论 反晕征具有一定特征性,常见于机化性肺炎、肺结核和真菌感染,结合其他临床资料,有助于鉴别诊断并指导临床决策.

Objective To describe diseases that may present with the reversed halo sign （RHS） on high-resolution CT,and therefore to improve the recognition of this thoracic radiological feature.Methods We retrospectively reviewed the HRCT scans and medical records of 5 patients who presented with RHS on chest CT from Peking University Third Hospital.With ＆quot;reversed halo sign,fairy ring,atoll sign＆quot; as the Chinese and English keywords,420 cases from the literatures were also reviewed through PubMed,Wanfang and CNKI databases until August 2015.Results The 5 patients were all males,aging 19-55 years.The diagnosis of the diseases included cryptogenic organizing pneumonia （patient 1）,pulmonary tuberculosis （patient 2）,pulmonary infarction （patient 3）,pulmonary edema （patient 4） and mycoplasma pneumonia （patient 5）.Literature review showed that RHS was observed in 206 cases of infectious pulmonary diseases and 219 cases of noninfectious pulmonary diseases.Invasive fungal infection （including 59 cases of mucormycosis and 27 aspergillosis） and pulmonary tuberculosis （79 cases） predominated in infectious pulmonary diseases.However,in non-infectious pulmonary diseases,RHS was most frequently observed in organizing pneumonia （66%）,sarcoidosis,lung cancer,pulmonary infarction,pulmonary edema and other interstitial lung diseases.There were some differences in the morphologic findings of RHS among invasive fungal infection,pulmonary tuberculosis and organizing pneumonia.In addition,our patient with mycoplasma pneumonia was the first case reported to present with RHS on HRCT.Condusions Although a wide spectrum of pulmonary diseases may present with RHS on chest CT,this sign is stilla characteristic thoracic radiological feature,which is more commonly found in organizing pneumonia,pulmonary tuberculosis and invasive fungal infection,and is helpful in differential diagnosis.