bronchiolitis with air trapping can have appearance of decreased lung density on expiration related: tags: #permanent source: An Algorithmic Approach to Lung Disease on expiration, normal lung becomes denser and whiter. Abnormal lung remains dark. Links to this note An Algorithmic Approach to Lung Disease bronchiolitis with air trapping can have appearance of decreased lung density on expiration respiratory bronchiolitis bronchiolitis with air trapping can have appearance of decreased lung density on expiration