Abstract
We report here on the redistributed regional ventilation abnormalities after the administration of a bronchodilator and as seen on xenon-inhaled dual-energy CT in a patient with asthma. The improved ventilation seen in the right lower lobe and the decreased ventilation seen in the right middle lobe after the administration of a bronchodilator on xenon-inhaled dual-energy CT could explain a positive bronchodilator response on a pulmonary function test. These changes may reflect the heterogeneity of the airway responsiveness to a bronchodilator in patients with asthma.