Figure 1From: Sputum matrix metalloproteinase-9 is associated with the degree of emphysema on computed tomography in COPD Correlation of sputum MMP-9 concentration (ng/ml) with computed tomography measure of emphysema [the low attenuation areas below −950 Hounsfield Units taken as an index of emphysema (% LAA −950) [r = 0.442 (0.171, 0.634), p = 0.020)]. Back to article page