From the Guidelines
The recommended CT modality for evaluating pulmonary contusion is contrast-enhanced CT of the chest, as it is the preferred imaging workup of suspected chest trauma. This is based on the most recent evidence from the Journal of the American College of Radiology, which states that contrast-enhanced CT of the chest is more sensitive and specific for chest trauma than conventional radiographs 1. The use of contrast-enhanced CT allows for the detection of vascular injuries, which may not be visible on non-contrast CT scans.
Some key points to consider when evaluating pulmonary contusion with CT include:
- The sensitivity of CT for detecting pulmonary contusions approaches 100%, compared to approximately 70% for chest X-rays 1
- CT scans can identify contusions that may not be visible on plain films, especially in the early post-injury period
- CT imaging is superior to chest radiography for detecting pulmonary contusions and can differentiate contusions from other thoracic injuries such as lacerations, pneumothorax, or hemothorax
- Follow-up imaging may be necessary to monitor progression, particularly in the first 24-48 hours when contusions can evolve and expand
In emergency trauma settings, a contrast-enhanced CT may be performed as part of a comprehensive trauma protocol to evaluate multiple organ systems simultaneously. The CT scan should be performed promptly after trauma, ideally within hours of injury, to establish baseline findings and guide management decisions.
From the Research
CT Modality for Pulmonary Contusion
- The recommended CT modality for evaluating pulmonary contusion is multidetector-row computed tomography (MDCT) 2.
- MDCT is a more sensitive modality compared to conventional radiography (CR) in detecting pulmonary injuries, including occult pulmonary contusion (OPC) 2.
- The use of MDCT can help identify pulmonary contusion that is not visible on chest x-ray films, allowing for earlier diagnosis and treatment 3.
- MDCT has been shown to be highly sensitive in identifying pulmonary contusion and may help predict the need for mechanical ventilation 3.
Comparison with Other Modalities
- Ultrasonography has been found to be a useful tool in detecting pulmonary contusion, with a high sensitivity and specificity 4, 5.
- However, the diagnostic accuracy of ultrasonography can vary depending on the operator, frequency of the transducer, and sample size 4.
- Radiography has been shown to have a lower sensitivity compared to MDCT and ultrasonography in detecting pulmonary contusion 4, 5.
- 99mTc-DTPA radioaerosol inhalation lung scan has been found to be a useful adjunct to chest CT scanning for detecting mild pulmonary contusion 6.
Clinical Implications
- The early detection of pulmonary contusion using MDCT or ultrasonography can help guide treatment and improve patient outcomes 3, 2.
- The identification of OPC on MDCT has been found to be associated with a better outcome compared to pulmonary contusion visible on both CR and MDCT 2.
- The use of MDCT and ultrasonography can help reduce the risk of complications, such as pneumonia and adult respiratory distress syndrome, in patients with pulmonary contusion 3, 4.