Imaging of small airways and emphysema.

High-resolution chest computed tomography (CT) is one of the most useful techniques available for imaging bronchiolitis because it shows highly specific direct and indirect imaging signs. The distribution and combination of these various signs can further classify bronchiolitis as either cellular/inflammatory or fibrotic/constrictive. Emphysema is characterized by destruction of the airspaces, and a brief discussion of imaging findings of this class of disease is also included. Typical CT findings include destruction of airspace, attenuated vasculatures, and hyperlucent as well as hyperinflated lungs.