Table 1.
Comparison of baseline characteristics.
Table 2.
Comparison of CT measures of emphysema and air trapping.
Figure 1.
Correlation (Pearson’s correlation r) between the FEV1/FVC ratio with emphysema-like changes (%LAA<−950 HU at end inspiration) and gas trapping (%LAA<−856 HU at end expiration), for the whole lung and separately for the right middle lobe.
FEV1 = Forced Expiratory Volume in the first second. FVC = Forced Vital Capacity. LAA = Low Attenuation Areas. HU = Hounsfield Units. p<0.05 for all correlations. Right middle lobe showed significantly less correlation for FEV1/FVC (p<0.01).
Figure 2.
Example of a CT scan obtained from a GOLD 0 smoker with FEV1 %predicted of 106 and an FEV1/FVC ratio of 0.78.
As seen in the left panel, the lungs were segmented, via VIDA’s Apollo Software, automatically with automated delineation of the individual lung lobes (Right Upper Lobe: Pink; Right Middle Lobe: Purple; Right Lower Lobe: Yellow; Left Upper Lobe Green, Left Lower Lobe: Blue). In the right panel, the distribution of the clustered regions of emphysema-like lung are shown as spheres demonstrating the cluster size expressed as sphere diameter and the centroid of the clustered region. Emphysema-like lung was defined at voxels below −950 HU. Spheres are color coded similarly to the coding in the left panel to distinguish lobar locations. The lobar distribution of percent emphysema-like lung is tabulated in the upper right portion of the right panel. Note that the right middle lobe shows significantly greater presence of emphysema-like lung as compared with the other lobes. However, the PFTs are more reflective of the percent emphysema in all lobes other than the right middle lobe.
Table 3.
Correlations between CT measures and FEV1/FVC for Right Lung with and without middle lobe.