Volume 150, Issue 6, Pages 1281-1290 (December 2016) Measuring Airway Remodeling in Patients With Different COPD Staging Using Endobronchial Optical Coherence Tomography  Ming Ding, PhD, Yu Chen, PhD, Wei-Jie Guan, PhD, Chang-Hao Zhong, MD, Mei Jiang, MD, Wei-Zhan Luo, MD, Xiao-Bo Chen, MD, Chun-Li Tang, MD, Yan Tang, MD, Qi-Ming Jian, MD, Wei Wang, MD, Shi-Yue Li, MD, Nan-Shan Zhong, MD  CHEST  Volume 150, Issue 6, Pages 1281-1290 (December 2016) DOI: 10.1016/j.chest.2016.07.033 Copyright © 2016 American College of Chest Physicians Terms and Conditions

Figure 1 Cross-sectional images of endobronchial optical coherence tomography (EB-OCT) in the (A) fifth-, (B) seventh-, and (C) ninth-generation bronchi. Compared with never-smokers (A1, B1, C1), stage III-IV in patients with COPD is characterized by the most significant mucosal thickening and blurred submucosal layer (A3, B3, C3), followed by heavy smokers with normal FEV1 (SNL) (A2, B2, C2). CHEST 2016 150, 1281-1290DOI: (10.1016/j.chest.2016.07.033) Copyright © 2016 American College of Chest Physicians Terms and Conditions

Figure 2 Longitudinal EB-OCT images demonstrating the morphologic differences of a never-smoker, SNL, and a patient with stage III COPD. Tapering of the inner airway lumen is most significant in (C) COPD (stage III, followed by (A) never-smokers and (B) SNL. See Figure 1 legend for expansion of abbreviations. CHEST 2016 150, 1281-1290DOI: (10.1016/j.chest.2016.07.033) Copyright © 2016 American College of Chest Physicians Terms and Conditions

Figure 3 Trends in tapering of EB-OCT parameters of each generation of bronchi among never-smokers, SNL, and patients with COPD. (A) The Ai7 of stage II COPD is smaller than that of stage I COPD (P = .017) but greater than that of stage III-IV COPD (P = .003). (B) Similar trend of changes seen in A. The dashed line indicates an inner airway diameter of 2 mm. * Indicates that the among-group differences are statistically significant. (C) # Indicates no significant difference between SNL and patients with COPD and among various stages of COPD (all P > .05). SNL present with greater airway wall thickness than do never-smokers in the seventh-, eighth-, and ninth-generation bronchi (all P < .001). GOLD = Global Initiative for Lung Disease. See Figure 1 legend for expansion of other abbreviations. CHEST 2016 150, 1281-1290DOI: (10.1016/j.chest.2016.07.033) Copyright © 2016 American College of Chest Physicians Terms and Conditions

Figure 4 Correlation between FEV1% predicted and Ai3-6, Ai7-9 and Aw3-6, Aw7-9. (A and B) Ai3-6 and Ai7-9 are significantly correlated with FEV1% predicted (r = 0.731; P < .001 and r = 0.768; P < .001). (C and D) Correlation is significant between Aw3-6 and FEV1% predicted (r = –0.591; P < .001) but not in Aw7-9 (r = 0.069; P = .575). Dashed lines correspond to COPD staging (ie, FEV1% predicted = 30%, 50%, and 80%). Aw = airway wall area. See Figure 3 legend for expansion of other abbreviations. CHEST 2016 150, 1281-1290DOI: (10.1016/j.chest.2016.07.033) Copyright © 2016 American College of Chest Physicians Terms and Conditions