title: Airway obstruction in asthmatic and healthy individuals: inspiratory and expiratory thin-section CT findings.
abstract: OBJECTIVE
  To determine differences in computed tomographic (CT) findings in asthmatic and healthy individuals and to correlate the findings with severity of airway obstruction.
  
  
  METHODS
  Thirty-nine asthmatic patients and 14 healthy subjects were prospectively evaluated with thin-section CT. Inspiratory CT scans were subjectively evaluated for presence of bronchial wall thickening, bronchial dilatation, and mosaic lung attenuation; expiratory scans were subjectively evaluated for presence of air trapping. Objective measurement of bronchoarterial-diameter ratio was performed on inspiratory scans. CT findings were compared with pulmonary function test results.
  
  
  RESULTS
  Bronchial wall thickening, severe air trapping, and reduced bronchoarterial-diameter ratio were observed more commonly in asthmatic patients than in healthy subjects. Bronchial wall thickening was more prevalent among patients with severe airflow obstruction (10 of 12 readings [83%]) than in patients with normal airflow (15 of 40 readings [38%]) or mild obstruction (nine of 26 readings [35%]). Other subjectively determined CT findings did not correlate with pulmonary function test results. The mean bronchoarterial-diameter ratios +/- 1 standard deviation were 0.65 +/- 0.16 in healthy subjects and 0.60 +/- 0.16, 0.60 +/- 0.18, and 0.48 +/- 0.11 in patients with normal airflow and mild and severe obstruction, respectively.
  
  
  CONCLUSIONS
  Thin-section CT is of limited value in distinguishing asthmatic patients with normal airflow or mild airflow obstruction from healthy subjects.
authors.affiliation: Department of Radiology, University of British Columbia and Vancouver Hospital and Health Sciences Centre, Canada.
authors.forename: C S
authors.initials: CS
authors.lastname: Park
authors.forename: N L
authors.initials: NL
authors.lastname: Müller
authors.forename: S A
authors.initials: SA
authors.lastname: Worthy
authors.forename: J S
authors.initials: JS
authors.lastname: Kim
authors.forename: N
authors.initials: N
authors.lastname: Awadh
authors.forename: M
authors.initials: M
authors.lastname: Fitzgerald
mesh_terms: D000328:Adult; D000402:Airway Obstruction / Q000000981:diagnostic imaging*; D001249:Asthma / Q000150:complications / Q000000981:diagnostic imaging* / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012119:Respiration / Q000502:physiology*; D012129:Respiratory Function Tests; D014057:Tomography, X-Ray Computed