title: The correlation between lung sound distribution and pulmonary function in COPD patients.
abstract: BACKGROUND
  Regional lung sound intensity in chronic obstructive pulmonary disease (COPD) patients is influenced by the severity and distribution of emphysema, obstructed peripheral airways, and altered ribcage and diaphragm configurations and movements due to hyperinflation. Changes in the lung sound distribution accompanied by pulmonary function improvements in COPD patients were observed after bronchodilator inhalation. We investigated the association of lung sound distribution with pulmonary functions, and the effects of emphysematous lesions on this association. These studies were designed to acquire the basic knowledge necessary for the application of lung sound analysis in the physiological evaluation of COPD patients.
  
  
  METHODS
  Pulmonary function tests and the percentage of upper- and lower-lung sound intensity (quantitative lung data [QLD]) were evaluated in 47 stable male COPD patients (54 - 82 years of age). In 39 patients, computed tomography taken within 6 months of the study was available and analyzed.
  
  
  RESULTS
  The ratio of lower QLD to upper QLD showed significant positive correlations with FEV1 %predicted (%FEV1; ρ=0.45, p<0.005) and MEF50 %predicted (%MEF50; ρ=0.46, p<0.005). These correlations were not observed in COPD patients with dominant emphysema (% low attenuation area >40%, n=20) and were stronger in less emphysematous patients (n=19, %FEV1; ρ=0.64, p<0.005, %MEF50; ρ=0.71, p<0.001).
  
  
  CONCLUSIONS
  In COPD patients, the ratio of lower- to upper-lung sound intensities decreased according to the severity of obstructive changes, although emphysematous lesions considerably affected lung sound distribution.
authors.affiliation: Division of Respiratory and Infectious Diseases, Department of Internal Medicine, St. Marianna University School of Medicine, Kawasaki, Japan.
authors.forename: Masamichi
authors.initials: M
authors.lastname: Mineshita
authors.affiliation: Division of Respiratory and Infectious Diseases, Department of Internal Medicine, St. Marianna University School of Medicine, Kawasaki, Japan.
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Kida
authors.affiliation: Division of Respiratory and Infectious Diseases, Department of Internal Medicine, St. Marianna University School of Medicine, Kawasaki, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Handa
authors.affiliation: Division of Respiratory and Infectious Diseases, Department of Internal Medicine, St. Marianna University School of Medicine, Kawasaki, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Nishine
authors.affiliation: Division of Respiratory and Infectious Diseases, Department of Internal Medicine, St. Marianna University School of Medicine, Kawasaki, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Furuya
authors.affiliation: Division of Respiratory and Infectious Diseases, Department of Internal Medicine, St. Marianna University School of Medicine, Kawasaki, Japan.
authors.forename: Seiichi
authors.initials: S
authors.lastname: Nobuyama
authors.affiliation: Division of Respiratory and Infectious Diseases, Department of Internal Medicine, St. Marianna University School of Medicine, Kawasaki, Japan.
authors.forename: Takeo
authors.initials: T
authors.lastname: Inoue
authors.affiliation: Department of Radiology, St. Marianna University School of Medicine, Kawasaki, Japan.
authors.forename: Shin
authors.initials: S
authors.lastname: Matsuoka
authors.affiliation: Division of Respiratory and Infectious Diseases, Department of Internal Medicine, St. Marianna University School of Medicine, Kawasaki, Japan.
authors.forename: Teruomi
authors.initials: T
authors.lastname: Miyazawa
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000000981:diagnostic imaging / Q000503:physiopathology*; D011656:Pulmonary Emphysema / Q000000981:diagnostic imaging / Q000503:physiopathology*; D011859:Radiography; D012129:Respiratory Function Tests; D012135:Respiratory Sounds / Q000503:physiopathology*; D012720:Severity of Illness Index