Wang Guangli, Wang Lin, Ma Zhenshen, Zhang Chengqi, Deng Kai
From the Department of Radiology, Qianfoshan Hospital Affiliated to Shandong University, Jinan, People's Republic of China.
J Comput Assist Tomogr. 2015 Mar-Apr;39(2):171-5. doi: 10.1097/RCT.0000000000000187.
The objective of this study was to determine the capability of quantitative emphysema by computed tomography (CT) to assess pulmonary function impairment in a population of current smokers with and without airflow limitation.
Seventy-six subjects (30 normal smokers; 8 with mild obstruction; 17 with moderate obstruction; 13 with severe obstruction; 8 with very severe obstruction) underwent CT examinations and pulmonary function tests. For the quantitative assessment, percentages of low attenuation volume (%LAVs) of whole lung, right lung, left lung, and each lobe were obtained. Computed tomography measurements were related to lung function (forced expiratory volume in 1 second [FEV1], ratio of FEV1 to forced vital capacity, diffusing capacity for carbon monoxide [DLCO], ratio of residual volume to total lung capacity [RV/TLC]) by multivariate linear regression analysis.
Quantitative CT measurements of emphysema were moderately, negatively correlated to airflow limitation (FEV1 and ratio of FEV1 to forced vital capacity) (r = -0.68 to -0.52, P < 0.001). Except for right middle and lower lobes, all the quantitative CT measurements showed moderate, negative correlations with diffusing capacity (DLCO) (r = -0.63 to -0.54, P ≤ 0.001) and weak to moderate correlations with RV (RV/TLC) (r = 0.36-0.41, P < 0.01). As compared with control samples, the %LAV of whole lung, right lung, left lung, and each lobe was increased in patients with GOLD stages 2, 3, and 4 disease (P < 0.05), and the % LAV of whole lung, right lung and right upper lobe was increased in patients with GOLD stage 1 (P < 0.05).
Pulmonary function results, particularly DLCO and RV/TLC, were primarily affected by the % LAV of the upper lobes. Quantitative CT measurements of emphysema provides a morphological method to investigate lung function impairment in patients with chronic obstructive pulmonary disease.
本研究的目的是确定通过计算机断层扫描（CT）进行定量肺气肿评估在有和没有气流受限的现吸烟者群体中评估肺功能损害的能力。
76名受试者（30名正常吸烟者；8名轻度阻塞者；17名中度阻塞者；13名重度阻塞者；8名极重度阻塞者）接受了CT检查和肺功能测试。为进行定量评估，获取了全肺、右肺、左肺及每个肺叶的低衰减体积百分比（%LAVs）。通过多变量线性回归分析，将CT测量结果与肺功能（一秒用力呼气容积[FEV1]、FEV1与用力肺活量的比值、一氧化碳弥散量[DLCO]、残气量与肺总量的比值[RV/TLC]）相关联。
肺气肿的定量CT测量结果与气流受限（FEV1及FEV1与用力肺活量的比值）呈中度负相关（r = -0.68至-0.52，P < 0.001）。除右肺中叶和下叶外，所有定量CT测量结果与弥散量（DLCO）呈中度负相关（r = -0.63至-0.54，P≤0.001），与RV（RV/TLC）呈弱至中度相关（r = 0.36 - 0.41，P < 0.01）。与对照样本相比，GOLD 2、3和4期疾病患者的全肺、右肺、左肺及每个肺叶的%LAV均增加（P < 0.05），GOLD 1期患者的全肺、右肺和右上叶的%LAV增加（P < 0.05）。
肺功能结果，尤其是DLCO和RV/TLC，主要受上叶%LAV的影响。肺气肿的定量CT测量提供了一种形态学方法来研究慢性阻塞性肺疾病患者的肺功能损害。
