Department of Radiology, University Medical Center, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands.
Respir Med. 2010 Jan;104(1):76-82. doi: 10.1016/j.rmed.2009.08.004. Epub 2009 Sep 6.
To investigate impact of distribution of computed tomography (CT) emphysema on severity of airflow limitation and gas exchange impairment in current and former heavy smokers participating in a lung cancer screening trial.
In total 875 current and former heavy smokers underwent baseline low-dose CT (30 mAs) in our center and spirometry and diffusion capacity testing on the same day as part of the Dutch-Belgian Lung Cancer Screening Trial (NELSON). Emphysema was quantified for 872 subjects as the number of voxels with an apparent lowered X-ray attenuation coefficient. Voxels attenuated <-950 HU were categorized as representing severe emphysema (ES950), while voxels attenuated between -910 HU and -950 HU represented moderate emphysema (ES910). Impact of distribution on severity of pulmonary function impairment was investigated with logistic regression, adjusted for total amount of emphysema.
For ES910 an apical distribution was associated with more airflow obstruction and gas exchange impairment than a basal distribution (both p<0.01). The FEV(1)/FVC ratio was 1.6% (95% CI 0.42% to 2.8%) lower for apical predominance than for basal predominance, for Tlco/V(A) the difference was 0.12% (95% CI 0.076-0.15%). Distribution of ES950 had no impact on FEV(1)/FVC ratio, while an apical distribution was associated with a 0.076% (95% CI 0.038-0.11%) lower Tlco/V(A) (p<0.001).
In a heavy smoking population, an apical distribution is associated with more severe gas exchange impairment than a basal distribution; for moderate emphysema it is also associated with a lower FEV(1)/FVC ratio. However, differences are small, and likely clinically irrelevant.
探讨在参加肺癌筛查试验的当前和既往重度吸烟者中，计算机断层扫描（CT）肺气肿分布对气流受限严重程度和气体交换受损的影响。
共有 875 名当前和既往重度吸烟者在我们中心进行了基线低剂量 CT（30 mAs）检查，并在同一天进行了肺活量测定和弥散量检测，作为荷兰-比利时肺癌筛查试验（NELSON）的一部分。872 名患者的肺气肿通过具有明显降低 X 射线衰减系数的体素数量进行量化。衰减值<-950 HU 的体素被归类为代表严重肺气肿（ES950），而衰减值在-910 HU 和-950 HU 之间的体素代表中度肺气肿（ES910）。通过逻辑回归，调整肺气肿总量，研究分布对肺功能损害严重程度的影响。
对于 ES910，与基底分布相比，顶部分布与更多的气流阻塞和气体交换受损相关（均 p<0.01）。与基底分布相比，顶部分布的 FEV1/FVC 比值低 1.6%（95%CI 0.42%至 2.8%），Tlco/V(A) 的差异为 0.12%（95%CI 0.076%至 0.15%）。ES950 的分布对 FEV1/FVC 比值没有影响，而顶部分布与 Tlco/V(A) 降低 0.076%（95%CI 0.038%至 0.11%）相关（p<0.001）。
在重度吸烟人群中，与基底分布相比，顶部分布与更严重的气体交换受损相关；对于中度肺气肿，它也与较低的 FEV1/FVC 比值相关。然而，差异较小，可能在临床上无意义。
