Figure 3From: Lung density on high resolution computer tomography (HRCT) reflects degree of inflammation in smokers Lung density, measured as percentage of lung volume with attenuation −750 to −900 HU (%HDS) for never-smokers (NS), smokers (S), COPD current smokers (COPD-cs) and COPD ex-smokers (COPD-es). Back to article page