<unk>  is a manifestation of barotrauma most often seen in premature newborns who have respiratory distress syndrome. Rupture of pulmonary alveoli results in air passing into the interstitial space of the lung. The air has been described as being present in the interstitial spaces, surrounding the bronchovascular bundles, and in the pulmonary lymphatic channels of the interstitium. Radiographic presence of<unk>  serves as a warning sign of other complications of barotrauma, such as pneumothorax. In most patients,<unk>  is transient, lasting only for several days. Rarely,<unk>  can persist and form expanding, radiolucent masses. This is known as persistent<unk> .
Linear, oval, and occasional spherical cystic air-containing spaces throughout the lung parenchyma.
Interstitial changes are initially linear but may become more cystic as the air in the interstitium congregates locally.
Subpleural cysts also develop and may rupture to produce a pneumothorax.
Heart tends to get smaller as intrathoracic pressure increases and results in diminished venous return into the chest.
Overall lung volume is increased; however, the lungs are less compliant because they are splinted at a large volume by the air within the interstitium.
Pulmonary interstitial emphysema
Pulmonary consolidation
Pulmonary nodule
Multiple pulmonary nodules
Interstitial lung disease
Cavitary pneumonia
Trapped lung
Lymphocytic interstitial pneumonia