Which result would you expect to see on chest imaging in bronchiolitis?

• A. Pleural effusion
• B. Normal chest X-ray
• C. Hyperinflation
• D. Large focal consolidation

Answer: (C)

Bronchiolitis is an infection of the small airways that causes inflammation, edema, and mucus plugging, leading to obstruction of expiratory flow. When air trapping occurs, the lungs stay oddly inflated even after exhalation, so on a chest radiograph you typically see hyperinflation—lungs appear larger, the diaphragms look flattened, and there may be mild peribronchial thickening or patchy atelectasis at the bases. This pattern helps distinguish bronchiolitis from other conditions: pleural effusion isn’t a feature of uncomplicated bronchiolitis, and large focal consolidation would suggest pneumonia rather than bronchiolitis. While a normal X-ray can occur in milder cases, hyperinflation is the classic imaging finding you’d expect in bronchiolitis.