CT shows two pneumatoceles near the pleural surface with fluid (Traumatic pneumatocele Type I)
A laceration is defined as an abnormal intraparenchymal collection of air resulting from traumatic disruption of the lung architecture.
Types of laceration:
- Type 1 is an air-filled cavity with or without an air-fluid level, resulting from sudden compression of a pliable chest wall wherein the air-containing lung ruptures.
- Type 2 is an air-containing cavity in a paravertebral location, resulting from severe compression of the more pliable lower chest wall and sudden shifting of the lower lobe across the vertebral body causing a shearing type of injury.
- Type 3 is a small peripheral cavity or peripheral linear radiolucency that is always close to the chest wall where a rib has been fractured, resulting from a fractured rib that has punctured the lung.
- Type 4 is a result of previously formed, firm pleuropulmonary adhesions causing the lung to tear when the overlying chest wall is violently moved inward or fractures, diagnosed only at surgery or autopsy.
Unlike a simple contusion, which resolves fairly quickly and completely, a laceration generally takes weeks to months to resolve and may result in residual scarring.
Occasionally, pneumatoceles can become secondarily infected, resembling formation of a hematoma.