Penetrating thoracic trauma
Penetrating thoracic trauma, namely gunshot and stab injuries, vary widely in incidence globally but nevertheless result in high mortality and serious morbidity. CT is the modality of choice in imaging these patients and can reduce the need for surgical exploration.
Pathology
Penetrating thoracic trauma most commonly affects the chest wall, pleura and lungs (up to 97%) with precordial and periclavicular injuries less common . Accurate identification of the entry site(s) is important, although it should be noted that the wound tract can appear remote due to respiratory motion.
Radiographic features
Plain radiograph
In the typical trauma setting a supine AP radiograph is acquired. Despite the inherent limitations of this technique, many pathologies can be easily identified :
- pneumothorax, pneumomediastinum, hemothorax, subcutaneous emphysema
- pulmonary opacities representing contusion, laceration, etc
- abnormal cardiomediastinal contour representing hematoma from cardiac or mediastinal injury
- rib fractures
- foreign bodies, e.g. bullets/bullet fragments, knife blade
CT
In a stable patient, contrast-enhanced CT is the modality of choice to assess for thoracic injuries. CT can be used to delineate the wound track and identify any foreign bodies (e.g. bullets).
In addition to injuries seen on plain radiography, CT is more sensitive in assessing for :
- mediastinal injuries
- esophageal injury
- tracheal injury
- cardiac injury
- most commonly present with cardiac tamponade
- right ventricle most commonly injured
- thoracic aortic injury (uncommon)
- detecting small pneumothorax/hemothorax not seen on plain radiographs
- subclavian artery injury
- diaphragmatic injury