title: Thin-section CT in patients with cystic fibrosis: correlation with peak exercise capacity and body mass index.
abstract: OBJECTIVE
  To evaluate whether thin-section chest computed tomographic (CT) findings correlate with exercise capacity, body mass index (BMI), dyspnea, and leg discomfort in patients with cystic fibrosis (CF).
  
  
  METHODS
  Institutional ethics committee approval was obtained, and patients provided written informed consent. Twenty-two patients (13 male and nine female patients; mean age, 22 years +/- 5.9; age range, 17-41 years) with stable CF underwent thin-section CT and exercise testing on a cycle ergometer. Three radiologists blinded to the clinical severity of disease and the spirometric findings of all patients independently and randomly scored all scans with a modified Bhalla scoring system. The primary measurement of the outcome of exercise testing was percentage of predicted peak O2 uptake. Univariate (Spearman rank correlation) and multivariate analyses were used to compare thin-section CT, clinical (age, sex, spirometric data, and BMI), and exercise measurements.
  
  
  RESULTS
  The correlation between total thin-section CT score and percentage of predicted peak O2 uptake was stronger than the correlation between the percentage of predicted peak O2 uptake and any clinical measurement (R = -0.60, P < .01). The thin-section CT structural abnormalities that had the strongest correlation with percentage of predicted peak O2 uptake were severity of bronchiectasis and presence of sacculations or abscesses (R = -0.70 and -0.71, respectively; P < .01). Multivariate analysis showed total thin-section CT score to be the only significant predictor of exercise capacity, accounting for 42% of the variance in percentage of predicted peak O2 uptake.
  
  
  CONCLUSIONS
  In patients with CF, the correlation between thin-section CT score and exercise limitation is stronger than that between spirometry results or BMI and exercise limitation.
authors.affiliation: Department of Radiology, St Vincent's University Hospital, Dublin, Ireland. jddodd@partners.org
authors.forename: Jonathan D
authors.initials: JD
authors.lastname: Dodd
authors.forename: Sinead C
authors.initials: SC
authors.lastname: Barry
authors.forename: Rupert B M
authors.initials: RB
authors.lastname: Barry
authors.forename: Charles G
authors.initials: CG
authors.lastname: Gallagher
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Skehan
authors.forename: James B
authors.initials: JB
authors.lastname: Masterson
mesh_terms: D000293:Adolescent; D000328:Adult; D015992:Body Mass Index; D003550:Cystic Fibrosis / Q000000981:diagnostic imaging* / Q000473:pathology / Q000503:physiopathology; D017079:Exercise Tolerance; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging / Q000473:pathology; D008297:Male; D015999:Multivariate Analysis; D010101:Oxygen Consumption / Q000502:physiology*; D012044:Regression Analysis; D013147:Spirometry; D014057:Tomography, X-Ray Computed / Q000379:methods*