[High resolution computed tomography (HRCT)]

The airway wall thickens in patients with asthma. Evaluating the airway wall thickening, which contributes to airflow obstruction, is useful to clarify the pathogenesis of irreversible or refractory airflow obstruction in asthma. Although biopsies can demonstrate several qualitative changes of the bronchial wall, they cannot precisely assess changes in airway smooth muscle or the thickening of the whole airway wall. Whole airway wall thickening can be measured with high-resolution computed tomography (HRCT), which is easier method than bronchial biopsy. The information by HRCT may be useful to treat patients with asthma.