ABSTRACT
The development of bullae is common in COPD. Bullae are thin-walled (<1 cm) air spaces as a result of destruction of the alveolar walls. Bullae are seen as thin-walled lucencies, commonly round in shape that compress the normal lung and distort the vasculature that surrounds them. It can be difficult to distinguish an apical bulla from a pneumothorax. The shape of the superior border of the lung may help. If it remains convex from the superior margin to the lateral margin, this is more characteristic of a pneumothorax. An apical bulla will result in a concave shape of the superior margin of the lung. An infected bulla may have an air-fluid level.
