Figures
- FIGURE 1
Overview of used materials and methods. 21 explant lungs were collected, comprising seven unused donor lungs, seven chronic obstructive pulmonary disease (COPD) lungs and seven COPD lungs with bronchiectasis. a) Of each group, five lungs of five different individuals were prepared for freezing and computed tomography (CT) scanning, and further processed to obtain four tissue cores per lung for microCT. b) Lobes from two lungs per group, obtained from two different individuals, were separated and air-dried to obtain microCT scans of the entire lobes.
- FIGURE 2
Bifurcation numbers and diameters on computed tomography (CT) images of frozen lungs. Results of measurements on CT images of control lungs (n=5), chronic obstructive pulmonary disease (COPD) lungs (n=5) and COPD lungs with bronchiectasis (n=5). a) Number of bifurcations per generation; b) diameters of airway segments per generation; c) widest diameter per bifurcation, lack of tapering. Results are presented as mean±sem. The reported p-value is the result of two-way ANOVA with symbols representing significant results of Tukey's post hoc test. *: p<0.05, **: p<0.01, ***: p<0.001 for COPD with bronchiectasis compared to COPD; #: p<0.05, ###: p<0.001 for COPD compared to control; ¶: p<0.05, ¶¶¶: p<0.001 for COPD with bronchiectasis compared to control.
- FIGURE 3
Airway segmentation of lower lobes on micro-computed tomography images. Lower lobes of a) control lung, b) chronic obstructive pulmonary disease (COPD) lung and c) COPD lung with bronchiectasis. The upper panels show the bronchial tree after segmentation, projected on the contours of the lobe. The lower panels show the same bronchial tree after automated annotation, with each colour representing a different generation within the lobe.
- FIGURE 4
Airway numbers and diameters as calculated on segmented airway models obtained by micro-computed tomography (microCT) of air-dried lobes. Results of measurements on microCT of control lobes (n=2 upper and n=2 lower lobes), chronic obstructive pulmonary disease (COPD) lobes (n=2 upper and n=2 lower lobes) and COPD lobes with bronchiectasis (n=2 upper and n=2 lower lobes). a, b) numbers of airways per generation; c, d) average diameters of airway segments per generation in upper (a, c) and lower (b, d) lobes. e, f) Airways in the lower lobes were separated based on diameter ≤2 mm and >2 mm, respectively. Data are presented as mean±sem. The reported p-value is the result of two-way ANOVA with symbols representing significant results of Tukey's post hoc test. *: p<0.05, **: p<0.01 and ***: p<0.001, for COPD with bronchiectasis compared to control; #: p<0.05, ##: p<0.01, ###: p<0.001 for COPD with bronchiectasis compared to COPD; ¶: p<0.05, ¶¶: p<0.01, ¶¶¶: p<0.001 for COPD compared to control.
Tables
- TABLE 1
Characteristics of patients from whom an explanted lung was used for computed tomography
Controls COPD COPD with bronchiectasis p-value Subjects 5 5 5 Male/female 4/1 1/4 5/0 0.020 Age years 60 (52–69) 60 (56–62) 60 (54–61) 0.95 Height cm 175 (164–178) 161 (157–169) 173 (173–179)* 0.031 BMI kg·m−2 24.8 (24.3–26.9) 22.0 (21.1–24.3) 21.0 (15.8–25.7) 0.16 Smoking pack-years NA# 30 (30–38) 39 (28–65) 0.55 Sputum production NA 1 4 0.058 Use of azithromycin NA 1 4 0.058 Exacerbations per year n NA 2 (1–3) 3 (2–4) 0.41 FVC L NA 1.83 (1.66–2.07) 2.48 (2.02–3.47) 0.032 % pred NA 65 (52–77) 61 (48–79) 1.00 FEV1 L NA 0.83 (0.60–0.86) 0.90 (0.62–1.18) 0.73 % pred NA 30 (28–34) 22 (15–33) 0.31 FEV1/FVC NA 0.40 (0.31–0.52) 0.32 (0.22–0.38) 0.15 DLCO % pred NA 34 (32–45) 28 (21–43) 0.42 Lobes with bronchiectasis n NA 0 2 (2–2.5) Modified Reiff score NA NA 5 (4–6) Data are presented as n or median (interquartile range), unless otherwise stated. Chi-squared, Kruskal–Wallis with Dunn's post hoc test and Mann–Whitney tests were used. COPD: chronic obstructive pulmonary disease; BMI: body mass index; FVC: forced vital capacity; FEV1: forced expiratory volume in 1 s; DLCO: diffusion capacity of the lung for carbon monoxide; NA: not applicable. #: these donors were registered as nonsmokers at the time of allocation. *: p<0.05 compared to COPD.
- TABLE 2
Results of ex vivo computed tomography scans of the explanted lungs
Control COPD COPD with bronchiectasis p-value Left/right lung n 0/5 4/1 3/2 Total lung volume L 3.5 (2.7–3.6) 3.1 (2.6–3.4) 4.2 (3.5–5.0) 0.10 Lung mass g 433 (316–486) 266 (227–300) 455 (370–561)# 0.030 Lung density g·L−1 125 (117–134) 90 (78–99) 105 (82–151) 0.061 Area <−950 HU % 17.9 (11.2–22.1) 44.0 (35.4–49.4)* 31.2 (14.4–47.5) 0.027 Airway generations n 16 (15–16.0) 12 (12–14)* 15 (15–16)# 0.011 Data are presented as median (interquartile range), unless otherwise stated. p-values obtained by Kruskal–Wallis test. COPD: chronic obstructive pulmonary disease. Significant results found by Dunn's post hoc test: *: p<0.05 compared to control; #: p<0.05 compared to COPD.
- TABLE 3
Characteristics of subjects and results of airway segmentation on lobar micro-computed tomography
Control COPD COPD with bronchiectasis Sex M M M M M M Age years 58 57 64 64 61 65 Height cm 185 180 170 168 173 170 Weight kg 95 80 70 62 78 60 BMI kg·m−2 27.8 24.7 24.2 22.0 26.0 20.8 Smoking pack-years NA¶ NA¶ 40 40 50 40 FVC L NA NA 3.18 1.65 2.48 3.70 % pred NA NA 84 45 61 97 FEV1 L NA NA 0.82 0.88 0.48 1.38 % pred NA NA 28 30 15 46 FEV1/FVC NA NA 0.26 0.53 0.19 0.37 DLCO % pred NA NA 32 34 38 28 Lobes with bronchiectasis n NA NA 0 0 2 3 Modified Reiff score NA NA NA NA 4 4 Right/left lung Right Left Right Left Right Left Upper lobe# Volume L NA NA 2.477 1.697 2.095 1.863 Area <−950 HU % NA NA 38 40 37 35 Generations n 19 19 14 14 14 18 Airways n 1478 958 324 224 602 628 Lower lobe Volume L NA NA 1.625 1.317 1.329 0.847 Area <−950 HU % NA NA 33 38 24 23 Generations n 22 19 19 17 20 17 Airways n 1350 1129 364 384 683 926 Individual results are presented. COPD: chronic obstructive pulmonary disease; M: male; BMI: body mass index; FVC: forced vital capacity; FEV1: forced expiratory volume in 1 s; DLCO: diffusing capacity of the lung for carbon monoxide; NA: not applicable. #: sum of upper and middle lobe in case of right lung; ¶: these donors were registered as nonsmokers at the time of allocation.
Supplementary Material
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Supplementary material ERJ-02166-2018.Supplement
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