SARS的胸部X线与CT诊断

目的 评价X线平片和CT检查在严重急性呼吸综合征(SARS)的诊断价值。方法 回顾性分析29例临床诊断SARS的患者，对发病后的一系列胸片和CT影像进行分析。结果 X线表现：发热后1周内胸片显示单侧或双侧肺局灶性斑片状模糊影，然后迅速扩大到其他肺野，部分呈片团状弥漫分布，部分融合呈大片状，中心密度高，周边密度低，可见支气管气像。按病变高峰期侵犯肺的范围将病变分为轻、中、重度，轻度5例，中度10例，重度14例。CT表现：发病1～10d有4例CT扫描显示两肺多发斑片状实变影，边缘模糊，部分融合成大片状，可见支气管气像。发病10～30d有9例进行CT检查，表现为两肺大部或弥漫磨玻璃样改变，肺间质增厚，呈粗大网状，夹杂斑块状肺实变影，胸膜下区可见小叶过度充气征象；发病30d后，有19例进行检查，2例CT表现正常，17例主要表现为两肺局灶或广泛性不同程度的肺间质增厚影像。结论 SARS同时存在急性肺炎和急性间质性肺炎的影像改变，在治疗过程中，一系列胸片检查有助于掌握病情的变化，CT检查能较准确地评价肺部病变。

Chest X-ray and CT in the diagnosis of SARS

Objective To evaluate the characteristic changes and diagnostic value of chest roentgenography and CT in severe acute respiratory syndrome (SARS). Methods Serial roentgenography and CT findings in 29 confirmed SARS patients were retrospectively analyzed. Results On roentgenography, the main abnormality was unilateral or bilateral localized patchy clouding opacity in the early phase of SARS (within one week). The opacity progressed quickly into other parts of the lung field over time. In 24 out of 29 cases (82.8%), the lesion developed into bilateral diffuse opacity involving most of the lungs in the fully advanced phase. Some lesions presented as diffuse small patches, while some other lesions as fused large patches with high density in the center and low density in the peripheral regions associated with air bronchium sign. According to the extent of the lesion involvement at the advanced phase, the lesion was classified into mild, moderate, and severe. The main CT findings in 4 cases were multiple patchy local consolidations in bilateral lungs with blurred margin and air bronchium in the early phase (1 to 10 days after onset). CT findings in 9 cases showed bilateral ground-glass changes and interstitial thickening together with mesh appearance and consolidation in the middle phase (10 to 30 days). CT findings revealed interstitial thickening and fine mesh appearance in 17 cases and normal in 2 cases in the recovery phase (after 30 days). Local fibrosis of the lungs was found in some cases after recovery in the follow-up examination. Conclusion There were radiological changes of both acute pneumonia and acute interstitial inflammation in SARS. Serial chest roentgenography was useful in the diagnosis and for the severity assessment of SARS. CT scan could provide more accurate assessment of the pathology of the lungs.