The use of imaging techniques for assessing severe childhood asthma

Computed tomography (CT) scans are usually performed in children with asthma to exclude alternative diagnoses. Technical improvements of high-resolution CT (HRCT) scans have increased the spatial resolution sufficiently for the theoretical quantification of bronchial wall thickening of the proximal airways and the assessment of small airway disease by the extent and degree of low attenuation areas, which are believed to represent air trapping. In contrast with adults, very few studies have been performed in children. The results suggest that the HRCT scan might be useful as a noninvasive technique for airway inflammation and airway remodeling. In the future, the potential use of HRCT scans for determining optimal treatment should be evaluated. However, several issues remain to be resolved, including the validity of algorithm reconstruction, the imaging parameters to be used, and the application of this technique to young children. Furthermore, because of its cost and the irradiation involved, this examination is highly unlikely to be used routinely for the management and follow-up of all children with asthma but will likely be restricted to patients with severe asthma.

Key words: Asthma, child HRCT scan, remodeling, bronchial wall thickening, small airway

Abbreviations used: BWT, Bronchial wall thickening, CT, Computed tomography, HRCT, High-resolution computed tomography, NO, Nitric oxide, RBM, Reticular basement membrane