Figure 1. Matched high-resolution computed tomography images of airways approximately 4 mm in diameter (arrows) from one dog at control (left), after 0.01 mg/ml ipratropium aerosol (center), and after 10 mg/ml ipratropium aerosol. Although 0.01 mg/ml ipratropium aerosol decreased the airway lumenal area compared with control, 10 mg/ml ipratropium aerosol increased the airway lumenal area compared with control.