From the Guidelines
CT scans are the preferred imaging modality for evaluating traumatic head injuries due to their high sensitivity and specificity for detecting intracranial injuries, including fractures, hemorrhages, and brain contusions, as supported by the most recent evidence from the American College of Radiology 1. Here's why:
- CT scans provide detailed 3D images of the entire head, allowing for better visualization of subtle injuries that may be missed on plain X-rays.
- CT can be performed quickly, which is crucial in emergency situations.
- Skull X-rays have limited utility in detecting intracranial injuries and may miss important findings. For suspected head trauma, patients should be taken directly for a CT scan if available, as it allows for rapid, accurate diagnosis and guides immediate treatment decisions, with the diagnostic benefit outweighing the risk of radiation dose in trauma cases 1. In settings where CT is not immediately available, skull X-rays may still have a role in initial triage, but they should not be relied upon to rule out significant intracranial injury, and patients with concerning symptoms should still be transferred for CT imaging when possible, as it is highly sensitive for the detection of findings that may require neurosurgical intervention 1.
From the Research
Utility of Skull X-rays in Evaluating Traumatic Head Injuries
- Skull X-rays are not commonly used for evaluating traumatic head injuries, as computed tomography (CT) scans are generally preferred due to their higher sensitivity and ability to detect a wider range of injuries 2, 3, 4, 5, 6
- CT scans are widely used to diagnose injuries and offer information on the specific location and extent of organ and tissue damage, including traumatic head injuries 2
- A study comparing CT scan results with autopsy findings found that CT scans were reliable and accurate in detecting traumatic injuries, including gunshot wounds to the head and bone fractures, but had limited ability to detect minor injuries to organs and soft tissues 2
Comparison with CT Scans
- CT scans are more sensitive than skull X-rays in detecting traumatic head injuries, including fractures and intracranial injuries 3, 4, 5, 6
- A study found that CT scans had a sensitivity of 50.2% and specificity of 76.6% in detecting C-spine injuries, while MRI had a higher sensitivity in detecting soft tissue injuries 4
- Another study found that CT scans were more capable of detecting vertebral fractures, while MRI was more capable of detecting soft tissue injuries 4
Clinical Criteria for CT Scans
- Clinical criteria, such as focal neurological deficit, anisocoria, skull fracture, and high-energy mechanism of trauma, can be used to determine the need for a CT scan in patients with mild traumatic brain injury 5
- A study found that high-energy trauma mechanism, superior injury of clavicle, and moderate to severe headache were positive predictors of CT findings in patients with mild traumatic brain injury 5
- Existing guidelines for CT scans in patients with head injury appear to predict traumatic CT abnormalities irrespective of timing of presentation, but may result in significant injuries not being identified in patients presenting after 24 hours of injury 6