正常人呼气相高分辨CT研究

Radiological study of expiratory high-resolution CT in healthy people

目的 探讨正常人呼气相HRCT扫描所见，分析其相关影像学表现。方法 对28例正常人行吸气相加呼气相HRCT扫描，定量分析扫描结果。结果 吸气相与呼气相HRCT比较，肺野CT值平均上升（224.84±97.98）Hu（70.14-544.05Hu）;呼气相全肺野CT值上升幅度与其面积减少正相关，相关系数r=0.693，P〈0.001。仰卧位时双肺承重区域CT值上升幅度大于非承重区域，P〈0.001;俯卧位测试结果与之相同，P〈0.001。呼气相CT值增加幅度随年龄的增加而降低。结论 正常受试者呼气相肺野CT值较吸气相平均上升224.84Hu;正常人呼气相HRCT肺野CT值上升程度与肺野面积减少正相关;正常人呼气相HRCT承重区CT值上升幅度大于非承重区，与体位无关;正常人呼气相CT值增加幅度随年龄增加而减低。

Objective To discuss and analyze the HRCT findings of the expiration in healthy people. Methods Twentyeight healthy persons are scanned by HRCT in the inspiration and expiration respectively. All the results have been analyzed quantitatively. Results Comparing with the inspiration, the expiratory cross-sectional lung attenuation rose by （224.84± 97.98） Hu（70.14-544. 05 Hu）. The extent of increase positively correlated with that of the decrease of its area （r= 0. 693, P〈0. 001）. The attenuation increasing amplitude of dependent lung regions was greater than that of nondependent lung regions （P〈0. 001）, both supinely and pronely. The increasing amplitude of attenuation in expiration descended, as the age ascended. Conclusion The cross-sectional lung attenuation of healthy subject in the expiration is greater than that in the inspiration by 224.84 Hu. The extent of increase of attenuation positively correlates with the extent of decrease of crosssection lung area. In healthy people, the attenuation increasing extent of dependent in expiration is larger than that of nondependent, which has no relation to the position. The increase extent ascends with the age.