肺泡微石症的影像学征象和临床表现

Imaging signs and clinical manifestation of alveolar microlithiasis

目的探讨肺泡微石症的影像学表现及临床病理特点。方法对1例PAM患者的临床表现、X线平片、HRCT影像学征象进行系统分析。结果肺泡微石症胸片表现为呈典型"暴风沙"改变,病变以双肺中下肺野内中带最密集,最显著。胸部HRCT较X线胸片更能明确、证实肺内散在的细小结节,钙化密度,尤其是中下肺野胸膜下及支气管血管束旁结节密集成堆时。典型者可呈"白描征"或"火焰征",部分患者肺实质内可出现间质性纤维化并合并不同程度的肺气肿,确诊本病主要靠病理学检查,病理可发现肺泡内弥漫性分布含钙、磷的细微结石。结论肺泡微石症是以双肺泡腔内弥漫分布微小结石为特征,具有独特的影像学征象,X线、HRCT是发现本病最基本的手段,在本病的诊断及鉴别诊断中起到很大作用,病理可确诊,本病预后较差。

Objective To investigate the imaging sings and clinical pathological characteristics of alveolar microlithiasis. Methods The clinical manifestations and imaging signs of X-ray film and HRCT of 1 patient with PAM were systematically analyzed. Results The chest film of alveolar microlithiasis showed typical change of ＂sand storm＂ ,and the pathological changes were most intensive and significant in the middle and lower lung field. The chest HRCT could confirm the scattered small nodules in lungs and the density of calcification more clearly than the chest film,especially when the subpleural and bronchovascular nodules were dense in the middle and lower lung field. Typical sings showed ＂line drawing＂ or ＂flame＂,and interstitial fibrosis with different levels of pulmonary emphysema occurred in lung parenchyma of some patients. It mainly depended on pathological examination to diagnose the disease, which could found the diffuse distribution of subtle stones containing calcium and phosphorus within the alveolus. Conclusion The characteristic of alveolar microlithiasis is the diffuse distribution of subtle stones,which has unique imaging signs. Therefore,X-ray and HRCT are the most basic ways to find the dlsease,which play important roles in the diagnosis and differential diagnosis. The disease can be finally diagnosed by pathologic diagnosis,however the prognosis is poor.