Thin-section CT evidence of bronchial thickening in children with stable asthma: Bronchoconstriction or airway remodeling?

Rationale and Objectives. The authors performed this study to determine if bronchial wall thickening is present in children with moderate to severe as thma during periods free from clinical bronchoconstriction. Materials and Methods. The authors obtained low (radiation) dose thin-secti on computed tomographic (CT) scans in each of 18 control subjects and 21 ch ildren with moderately severe but stable asthma. Spirometry was performed o n all subjects at the time of CT scanning. Bronchial wall thickness and bro nchial wall area were measured, and the percentage wall area (bronchial wal l area divided by bronchial cross-sectional area) was calculated. The autho rs performed best-fit regression analysis of wall thickness and percentage wall area versus bronchial diameter and qualitative analysis of images for bronchial wall thickening. Results. In asthmatic patients, the mean percentage of the predicted forced expiratory volume in 1 second was 0.88 +/- 0.09. The best fit regression l ine that demonstrated the relationship between wall thickness and bronchial diameter for patients with asthma differed significantly from that for con trol subjects (P < .005). The regression line that demonstrated the relatio nship between the percentage wall area and bronchial diameter for patients with asthma differed from that of the control subjects when bronchial wall thickness measurements were used to calculate the percentage wall area (P < .05), Results of qualitative analysis also showed significantly more bronc hial wall thickening in asthmatic patients than in control subjects (P < .0 01). Conclusion. Bronchial wall thickening detected at thin-section CT in childr en with moderately severe asthma cannot be attributed solely to bronchocons triction and may represent airway inflammation or remodeling.