title: The benefit of expiratory-phase quantitative CT densitometry in the early diagnosis of chronic obstructive pulmonary disease.
abstract: OBJECTIVE
  We aimed to compare the inspiratory and expiratory quantitative computed tomography (CT) densitometric data of healthy volunteers, individuals with chronic obstructive pulmonary disease (COPD) risk, and COPD patients to aid in the early diagnosis of COPD.
  
  
  METHODS
  Of the study patients, 14 were healthy volunteers (Group I), 12 were patients at risk for COPD (Group II), and 13 were COPD patients (Group III). The high-resolution CT was performed at three levels (the upper, middle, and lower parts of the lungs). All images were evaluated with a specific program for the segmentation of pulmonary parenchyma. The mean lung density (MLD) was measured, and the emphysema index (EI) was calculated using this program.
  
  
  RESULTS
  Both MLD values and calculated EI ratios showed significant differences between Groups I and III, and Groups II and III in both expiratory and inspiratory phases (P < 0.05). However, in the comparison of healthy volunteers and patients at risk for COPD (Group I and II), only expiratory-phase MLD values showed statistically significant difference (P < 0.001).
  
  
  CONCLUSIONS
  In patients at risk for COPD, expiratory-phase MLD measurements can be used as an early diagnostic method.
authors.affiliation: Department of Radiology, Düzce University School of Medicine, Düzce, Turkey. drfhbesir@gmail.com
authors.forename: Fahri Halit
authors.initials: FH
authors.lastname: Beşir
authors.forename: Kamran
authors.initials: K
authors.lastname: Mahmutyazıcıoğlu
authors.forename: Leyla
authors.initials: L
authors.lastname: Aydın
authors.forename: Remzi
authors.initials: R
authors.lastname: Altın
authors.forename: Kıyasettin
authors.initials: K
authors.lastname: Asil
authors.forename: Sadi
authors.initials: S
authors.lastname: Gündoğdu
mesh_terms: D000328:Adult; D042241:Early Diagnosis; D045853:Exhalation; D006801:Humans; D008297:Male; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000000981:diagnostic imaging* / Q000503:physiopathology; D014057:Tomography, X-Ray Computed