薄层螺旋CT评价无临床症状人群肺老化的初步研究

Thin-section spiral CT evaluation of morphologic effects of aging lung in asymptomatic adult subjects

目的应用薄层螺旋高分辨率CT(HRCT)评价无临床症状人群肺老化的各项影像学征象,分析其与被检查者年龄的相关性,探讨其临床诊断应用价值。方法应用薄层螺旋HRCT对106名无胸部疾病及临床症状者[分30～44岁(31例)、45～59岁(30例)和60岁以上(45例)3个年龄组]进行肺上中下野3个区域的高分辨CT扫描,观察肺间质性改变、肺气肿样改变、马赛克样灌注、肺叶密度梯度差异和胸膜肥厚5项征象,按照标准化评分系统进行评分,再应用SPSS软件对各个指标进行统计学分析。结果在3个年龄组中,肺间质性改变、肺气肿样改变和马赛克样灌注组间差异有统计学意义(χ2值分别为8.10、9.73和15.54,P值均<0.01);而肺叶密度梯度和胸膜肥厚差异无统计学意义(χ2值分别为3.66和3.24,P值均>0.05)。根据各征象的评价标准计算出的积分值与研究对象的年龄呈高度正相关(r=0.709,P<0.01)。结论无胸部疾病临床症状者HRCT可见肺间质性改变、肺气肿、马赛克样灌注、肺叶密度梯度差异和胸膜肥厚等结构改变,这些改变随年龄增长而增加。HRCT是评价早期肺老化的重要手段之一。

Objective To evaluate the imaging signs of aging lung in asymptomatic adult subjects by using thin-section spiral CT, and analyze the correlation between the signs and the age of examined cases, as well as probe their clinical application value. Methods One hundred and six healthy adult subjects were divided into 3 groups ： 30 to 44 years （ n = 31 ）, 45 to 59 years （ n = 30）, and over 60 years （ n = 45）, and all the subjects underwent thin-section spiral CT scans in the upper lung field, the middle lung field and the lower lung field. The evaluation indices included the lung interstitium changes, emphysematous changes, mosaic perfusion, dependent density difference, and pleural thickenning. According to the relative score standard, the above-mentioned indices were totally calculated and converted into the score value. The data were statistically processed with SPSS for Windows. Results Among the three groups, there were remarkable differences in the indices including the lung interstitium changes, emphysematous changes, and mosaic perfusion, respectively （ x^2= 8. 10, 9.73, 15. 54, P 〈 0.01 ）, while there existed no remarkable differences in dependent density difference and pleural thickenning, respectively （x^2 = 3.66, 3.24, P 〉 0. 05）. The score values had a significant positive correlation with the age （r = 0. 709, P 〈 0.01 ）. Conclusion The signs including the lung interstitium changes, emphysematous changes, mosaic perfusion, the dependent density difference, and pleural thickenning can be found in asymptomatic subjects, and they become prominent as the age increases. HRCT is one of the most important methods for evaluating the early signs of the senile lung.