Which chest radiograph finding is most consistent with an acute COPD exacerbation?

• A. Normal chest radiograph
• B. Hyperinflation with flattened diaphragm
• C. Infiltrates
• D. Pleural effusion

Answer: (B)

During an acute COPD flare, air trapping makes the lungs appear overexpanded on a chest radiograph. The classic finding is hyperinflation with flattening of the diaphragms. This happens because obstructed airways slow exhalation, so more air remains in the lungs at the end of expiration, increasing overall lung volume and pushing the diaphragms downward and flattening them. You may also see a widened retrosternal space and increased lung markings at the bases due to mild atelectasis, but the key clue is the hyperinflated, flattened diaphragms.

A normal chest radiograph can occur in some COPD patients, but it’s not the typical sign of an acute exacerbation. Infiltrates would suggest an infectious process like pneumonia, and a pleural effusion would indicate fluid accumulation rather than COPD-related air trapping.