title: Validation of human small airway measurements using endobronchial optical coherence tomography.
abstract: BACKGROUND
  Small airway remodeling is the cardinal feature underlying chronic airway diseases. There is no modality which identifies small airway pathological changes, which is crucial for early diagnosis, efficacy and prognostic assessment.
  
  
  OBJECTIVE
  To evaluate the usefulness of endobronchial optical coherence tomography (EB-OCT) in assessing small airways morphology in vivo.
  
  
  METHODS
  Twelve patients with pulmonary nodules scheduled for lung resection underwent spirometry, multi-detector computed tomography (MDCT) and EB-OCT. We measured D(mean) (mean luminal diameter), Ai (inner luminal area), Aw (airway wall area) and Aw% [Aw/(Ai + Aw) × 100%] from the 3rd to 5th generation bronchi of RB9 segment by MDCT. D(mean), Ai, Aw and Aw% from the 3rd to 9th generation bronchi of RB9 segment were measured by EB-OCT and histology. Correlations of these parameters, measured by three different methods, were evaluated. We recruited 4 COPD patients to determine if EB-OCT could identify peripheral airway remodeling.
  
  
  RESULTS
  The 4 parameters, measured by CT and EB-OCT, correlated significantly [D(mean) (r = 0.991), Ai (r = 0.997), Aw (r = 0.997), Aw% (r = 0.991), all P < 0.01]. Significant correlation were found for these parameters, measured by histology and EB-OCT, from the 3rd to 5th generation bronchi [D(mean) (r = 0.989), Ai (r = 0.997), Aw (r = 0.999), Aw% (r = 0.988), all P < 0.01], and from the 6th to 9th generation bronchi [D(mean) (r = 0.979), Ai (r = 0.997), Aw (r = 0.994) and Aw% (r = 0.988), all P < 0.01]. Significant small airways morphological abnormalities were observed in COPD patients.
  
  
  CONCLUSIONS
  EB-OCT, a minimally invasive imaging modality with high-resolution, is useful and clinically practical for assessing proximal and distal airways of human compared with CT and histology.
authors.affiliation: State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Disease, First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Disease, First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China.
authors.forename: Ming
authors.initials: M
authors.lastname: Ding
authors.affiliation: State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Disease, First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China.
authors.forename: Wei-jie
authors.initials: WJ
authors.lastname: Guan
authors.affiliation: Department of Cardiology, First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Disease, First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China.
authors.forename: Wei-zhan
authors.initials: WZ
authors.lastname: Luo
authors.affiliation: State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Disease, First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China.
authors.forename: Chang-hao
authors.initials: CH
authors.lastname: Zhong
authors.affiliation: State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Disease, First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China.
authors.forename: Mei
authors.initials: M
authors.lastname: Jiang
authors.affiliation: Department of Pathology, First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China.
authors.forename: Ju-hong
authors.initials: JH
authors.lastname: Jiang
authors.affiliation: Department of Pathology, First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China.
authors.forename: Ying-ying
authors.initials: YY
authors.lastname: Gu
authors.affiliation: State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Disease, First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China. Electronic address: lishiyue@188.com.
authors.forename: Shi-yue
authors.initials: SY
authors.lastname: Li
authors.affiliation: State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Disease, First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China. Electronic address: nanshan@vip.163.com.
authors.forename: Nan-shan
authors.initials: NS
authors.lastname: Zhong
mesh_terms: D000368:Aged; D056151:Airway Remodeling / Q000502:physiology*; D001980:Bronchi / Q000473:pathology*; D020680:Bronchoscopes; D001999:Bronchoscopy / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis* / Q000473:pathology / Q000503:physiopathology; D015203:Reproducibility of Results; D041623:Tomography, Optical Coherence / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000379:methods
keywords: EB-OCT; Histology; MDCT; Morphology; Small airways