机化性肺炎与社区获得性肺炎胸部CT的气腔实变影特征比较

Comparison of airspace consolidation in thoracic CT between organizing pneumonia and community acquired pneumonia

目的探讨胸部CT的气腔实变影对机化性肺炎(OP)和社区获得性肺炎(CAP)的鉴别诊断价值。方法回顾性分析2010年10月至2016年8月期间住院的胸部CT上主要为气腔实变影的56例OP及99例CAP患者的临床资料及CT资料,分析空气支气管征(ABG)及其他影像学特征在两组中分布的差异。结果 87.5%的OP患者胸部CT上有数量不等、形态各异的ABG,显著高于CAP组的72.7%(χ~2=4.558,P=0.033)。OP患者的ABG数量为4(2~8)个,显著高于CAP组的数量2(0~4)个(z=3.640,P=0.000)。在形态上,58.9%的OP患者存在全程空气支气管征(EABG),显著高于CAP组的21.2%(χ~2=22.413,P=0.000)。26.3%的CAP患者有断续ABG,16.1%的OP患者有断续ABG,差异无统计学意义(χ2=2.125,P=0.148)。牵拉性支气管扩张、磨玻璃影(GGO)在OP患者中更多见,分别为26.8%和39.3%,而在CAP组仅为1.0%和11.1%(均P<0.05)。1.0%的CAP患者有反晕征,显著低于OP组的26.8%(χ~2=25.671,P=0.000)。胸腔积液和支气管壁增厚在CAP患者中更常见,为56.6%和35.4%。多因素logistic回归分析结果显示EABG(OR=5.526,P=0.000)、牵拉性支气管扩张(OR=21.564,P=0.010)、GGO(OR=4.657,P=0.007)、反晕征(OR=13.304,P=0.023)为OP的危险因素,胸腔积液(OR=0.380,P=0.049)、支气管壁增厚(OR=0.073,P=0.008)为OP的保护因素。ABG与其他影像学特征的并存率在OP组与CAP组间差异均有统计学意义(P均<0.05)。结论胸部CT的气腔实变影的精细特征对OP及CAP的鉴别诊断具有一定的价值。EABG更多见于OP,当出现EABG或者ABG合并有牵拉性支气管扩张、GGO、反晕征时,需考虑OP的诊断。

Objective To explore the differential diagnosis value of airspace consolidation in thoracic CT between organizing pneumonia（OP） and acquired community pneumonia（CAP）. Methods A retrospective study was taken by retrieving the patients CT database from October 2010 to August 2016. Fifty-six consecutive patients with OP and 99 consecutive patients with CAP whose CT showed airspace consolidation were enrolled and their clinical characteristics and radiological characteristics were analyzed. Results The percentage of patients whose CT image showed various amount of air bronchogram（ABG） with different shapes is higher in OP group than that in CAP group（87.5% and 72.7% respectively, χ24.558, P=0.033）. The median and interquartile range amount of ABG in the OP patients were significantly higher than those in CAP group [4（ranged from 2 to 8） and 2（ranged from 0 to 4） respectively, z=3.640,P=0.000]. Morphologically, 58.9% of the OP patients showed entire air bronchogram（EABG） on the thoracic CT,significantly higher than that in CAP group（21.2%）（χ2=22.413, P=0.000）. Interrupted ABG was found in 26.3% of CAP patients, while 16.1% of OP patients shared same features and the difference was not statistically significant（χ2=2.125,P=0.148）. Traction bronchiectasis and ground glass opacity（GGO） were more likely to be found in the OP patients rather than CAP patients with 26.8% and 39.3% respectively, while they were found in 1.0% and 11.1% in the CAP patients（P〈0.05）. Reversed halo sign was found only 1.0% of the CAP patients, significantly lower than that in OP group, 26.8%（χ2=25.671, P=0.000）. Pleural effusion and bronchial wall thickening were more commonly found in the CAP group with56.6% and 35.4% respectively. By multivariate logistic analysis, EABG（OR=5.526, P=0.000）, traction bronchiectasis（OR=21.564, P=0.010）, GGO（OR=4.657, P=0.007） and reversed halo sign（OR=13.304, P=0.023） were significantly associated with OP, while pleural effusion（OR=0.380, P=0.049） and bronchial wall thickening（OR=0.073, P=0.008） were significantly associated with CAP. Other features in thoracic CT coexisting with ABG all reach significance statistically between the OP and CAP group（all P〈0.05）. Conclusions Airspace consolidation in thoracic CT may be valuable for the differential diagnosis between OP and CAP. EABG is more commonly found in OP patients than in CAP patients. When EABG exists or ABG coexists with traction bronchiectasis, GGO and reversed halo sign, a diagnose of OP should be considered.