Parrón Manuel, Torres Isabel, Pardo Mercedes, Morales Carmen, Navarro Marta, Martínez-Schmizcraft Marta
Servicio de Radiodiagnóstico, Hospital Universitario La Paz, Madrid, Spain.
Arch Bronconeumol. 2008 Jul;44(7):386-92.
The halo sign is a circular area of ground-glass attenuation that is seen around pulmonary nodules at computed tomography (CT). Although the sign is most often an indication of pulmonary hemorrhage, it may also accompany other lesions associated with different disease processes. Examples are hemorrhagic nodules of infectious origin (mucormycosis, candidiasis, tuberculosis, viral pneumonia, and invasive aspergillosis--the last being the most common cause of the CT halo sign); hemorrhagic nodules of noninfectious origin (Wegener granulomatosis, Kaposi sarcoma, and hemorrhagic metastases); tumor cell infiltration (bronchioloalveolar carcinoma, lymphoma, and metastasis with intra-alveolar tumor growth); and nonhemorrhagic lesions (sarcoidosis and organizing pneumonia). Diagnosis must therefore be based on careful consideration of all the CT chest findings within the context of the patient's clinical state. The aim of this review was to describe and illustrate different disease processes that appear as a halo sign on CT scans, to analyze the value of this diagnostic tool, and to assess its correlation with pathology findings.
晕征是在计算机断层扫描（CT）上可见于肺结节周围的磨玻璃样衰减的圆形区域。尽管该征象最常提示肺出血，但它也可能伴随与不同疾病过程相关的其他病变。例如，感染性来源的出血性结节（毛霉菌病、念珠菌病、结核病、病毒性肺炎和侵袭性曲霉病——最后一种是CT晕征最常见的原因）；非感染性来源的出血性结节（韦格纳肉芽肿、卡波西肉瘤和出血性转移瘤）；肿瘤细胞浸润（细支气管肺泡癌、淋巴瘤和肺泡内肿瘤生长的转移瘤）；以及非出血性病变（结节病和机化性肺炎）。因此，诊断必须在患者临床状况的背景下，仔细考虑所有胸部CT表现。本综述的目的是描述和说明CT扫描上表现为晕征的不同疾病过程，分析这种诊断工具的价值，并评估其与病理结果的相关性。
