Table 2.
Automated CT Scan Measure | CF | Disease Control | P Value |
Inspiratory airway counta | |||
Inspiratory slices per scan, No. | 16.1 (3.2) | 15.9 (2.4) | .82 |
Total | 13.2 (6.5) | 7.0 (2.6) | < .0001 |
Central | 11.4 (4.7) | 6.6 (2.2) | < .0001 |
Peripheral | 1.8 (2.0) | 0.4 (0.5) | .0003 |
Expiratory LAD (%)b | |||
Total | 11.4 (10.6) | 4.2 (2.6) | < .001 |
Upper lung zone | 15.0 (15.6) | 3.7 (4.6) | < .001 |
Middle lung zone | 9.4 (9.9) | 3.1 (2.7) | .002 |
Lower lung zone | 11.3 (10.6) | 5.5 (3.5) | .008 |
Expiratory fixed (%)c | |||
Total | 11.4 (10.4) | 4.0 (2.4) | < .001 |
Upper lung zone | 14.7 (15.0) | 2.6 (2.6) | < .0001 |
Middle lung zone | 9.1 (9.2) | 3.3 (2.6) | .002 |
Lower lung zone | 11.8 (11.0) | 5.5 (3.3) | .004 |
Data are presented as mean (SD). HRCT = high-resolution CT; LAD = low attenuation density. See Table 1 legend for expansion of other abbreviation.
CF: n = 35; disease control: n = 12. The number of visible airways (total, central, and peripheral) averaged over all inspiratory HRCT scan slices in an individual.
CF: n = 34; disease control: n = 12. Total LAD (%) averaged over six expiratory HRCT scan slices in an individual subject. Upper lung zones are composed of expiratory scan levels 1 and 2; middle lung zones are expiratory scan levels 3 and 4; and lower lung zones are expiratory scan levels 5 and 6.
CF: n = 34; disease control: n = 12. Air trapping score calculated using fixed −850 Hounsfield unit threshold.