Bullae

Bullae are often associated with emphysema. By definition, a bulla is a gas-containing, avascular area of lung at least 1 cm in diameter and with a wall thickness of at least 1 mm. The arrows indicate bullae visible on the chest x-ray (left) and CT scan (right) of a...

Air Bronchogram

The air bronchograms seen in this chest x-ray and CT scan represent lucent branching bronchi visible through surrounding (opaque) airspace disease.

Acinar Pattern

The acinar pattern is representative of airspace disease. Seen are ill-defined, round or elliptical nodules measuring 4–8 mm. They have a characteristic “fluffy” appearance and may take on a patchy distribution, with a later tendency to coalesce into a lobar or...