title: Comparison of a New Integral-Based Half-Band Method for CT Measurement of Peripheral Airways in COPD With a Conventional Full-Width Half-Maximum Method Using Both Phantom and Clinical CT Images.
abstract: OBJECTIVE
  To compare a new integral-based half-band method (IBHB) and a conventional full-width half-maximum (FWHM) method in measuring peripheral airway dimensions at airway phantoms and thin-section computed tomography of chronic obstructive pulmonary disease (COPD).
  
  
  METHODS
  The IBHB was validated and compared using airway phantoms and 50 patients with COPD. Airway parameters (wall area percentage [WA%], mean lumen radius, and mean wall thickness) were measured at fourth to sixth generations of the right apical bronchus. Matched results from 2 methods were compared and correlated with forced expiratory volume (FEV) in 1 second (FEV1), FEV1 / forced vital capacity (FVC), and global initiative for chronic obstructive lung disease (GOLD) stage. Linear regression analysis was performed using airway dimensions and emphysema index.
  
  
  RESULTS
  The IBHB generated more accurate measurements at phantom study. Measured airway parameters by both methods at thin-section computed tomography study were significantly different (all P < 0.05, paired t test). The IBHB method-measured WA% and wall thickness were significantly smaller. Mean WA% with IBHB also showed better correlation than that with FWHM (FEV1, r = -0.52 vs -0.28; FEV1 / FVC, r = -0.41 vs r = -0.20; GOLD, 0.52 vs 0.33, respectively). Linear regression analysis revealed fifth-generation WA% measured by IBHB was an independent variable, and addition to emphysema index increased predictability (FEV1, r = 0.63; FEV1 / FVC, r = 0.61; GOLD, r = 0.70).
  
  
  CONCLUSIONS
  The new IBHB measured peripheral airway dimensions differently than FWHM and showed better correlations with functional parameters in COPD.
authors.affiliation: From the Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea.
authors.forename: Young Hoon
authors.initials: YH
authors.lastname: Cho
authors.forename: Joon Beom
authors.initials: JB
authors.lastname: Seo
authors.forename: Namkug
authors.initials: N
authors.lastname: Kim
authors.forename: Hyun Joo
authors.initials: HJ
authors.lastname: Lee
authors.forename: Hye Jeon
authors.initials: HJ
authors.lastname: Hwang
authors.forename: Eun Young
authors.initials: EY
authors.lastname: Kim
authors.forename: Sang Young
authors.initials: SY
authors.lastname: Oh
mesh_terms: D000368:Aged; D000465:Algorithms; D001995:Bronchography / Q000295:instrumentation / Q000379:methods*; D005260:Female; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging*; D008297:Male; D019047:Phantoms, Imaging; D029424:Pulmonary Disease, Chronic Obstructive / Q000000981:diagnostic imaging*; D011856:Radiographic Image Enhancement / Q000379:methods*; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000295:instrumentation / Q000379:methods*