Fig 1.
Flowchart for the different exclusion criteria.
Table 1.
Patient population characteristics.
Table 2.
Results of correlation analyses.
Table 3.
Results of Mann-Whitney U test.
Table 4.
Subgroup discriminatory performance with and without CT parameters.
Table 5.
Lobe-wise values.
Fig 2.
Regional differences in attenuation histogram metrics between inspiration and expiration.
Difference in percentile values at −250 HU (between inspiration and expiration) in attenuation histograms (ΔP(−250 HU)) (a), mean HU ratio exp/insp (b) and mean (c), skewness (d) and kurtosis (e) of attenuation histograms in expiration in the subgroups are depicted as box charts for the total lung. Superimposed with color-coded lines are the mean values of the measure per total lung and per lobe for the two subgroups of patients. The lower lobes present with the highest mean density in expiration as well as with the smallest values for skewness, kurtosis and mean-HU-ratio compared to the upper lobes and the middle lobe. Differences between the two subgroups are most prominent in the lower lobes, and most striking for skewness exp and ΔP(−250 HU).
Fig 3.
Lobe-wise and total lung attenuation histograms with corresponding CT images in inspiration and expiration.
Three example patients (a, b, c) with their lobe-wise and total lung attenuation histograms (left) and coronal CT images in inspiration and expiration (right). The histograms display attenuation values on the x-axes (in HU) and frequency on the y-axis.