Chest

The plain AP films of this patient exemplify pulmonary edema. One can easily appreciate the fluffy white opacities throughout the lung field. Other signs such as vascular redistribution, peri-bronchial cuffing, and pleural effusion are difficult to appreciate on this study. However, Kerley B lines are seen, especially in the lower right lung field.

This young patient has emphysema as a result of alpha-1-antitrypsin deficiency. Hyperinflation is noted as a generalized increase in radiolucency due to increased aeration and spread of vasculature, an increased AP chest diameter and retrosternal airspace on the lateral view, and diaphragmatic domes projecting well below the normal level of the 10th rib posteriorly and the 6th rib anteriorly on the PA view.

Emphysema (PA Film) (left image)
Hyperinflation, darkened lung fields, and decreased vascular markings.

Emphysema (Lateral Film) (right image)
Large retrosternal airspace, increased AP diametre (barrel chest), flattened hemi-diaphragms.

The following is a useful mnemonic for the differential diagnosis of a cavitating lung lesion:

Cancer
Autoimmune
Vascular
Infection (e.g. Tuberculosis)
Trauma
Youth (congenital)

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 patient with bullous emphysema.

Ill-defined fluffy structures with confluences plus or minus air bronchograms. [Courtesy of Dr. M. Hutcheon]

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

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 segmental distribution (see images of a right middle lobe pneumonia under “Silhouette sign – RML”).