When is a computed tomography (CT) head scan indicated for a child with a head injury?

CT Head Scan Guidelines for Children with Head Injury

CT head scans should be performed in children with head injury based on validated PECARN criteria, with immediate imaging for those with GCS ≤13, altered mental status, signs of skull fracture, or other high-risk features, while avoiding unnecessary radiation in very low-risk patients. 1

Risk Stratification Approach

The decision to perform CT imaging in pediatric head trauma should follow a structured approach based on age and risk factors:

High-Risk Features (Immediate CT Recommended)

• Moderate to severe head trauma (GCS ≤13) - CT is strongly indicated due to higher incidence of intracranial injury 1
• Children ≥2 years with:
  • GCS of 14
  • Other signs of altered mental status
  • Signs of basilar skull fracture
  • Risk of clinically important TBI ~4.3% 1
• Children <2 years with:
  • GCS of 14
  • Other signs of altered mental status
  • Palpable skull fracture
  • Risk of clinically important TBI ~4.4% 1

Intermediate-Risk Features (CT vs. Observation)

• Children ≥2 years with:
  • GCS of 15 with normal mental status
  • No basilar skull fracture
  • But with: loss of consciousness, vomiting, severe mechanism of injury, or severe headache
  • Risk of significant injury ~0.8% 1
• Children <2 years with:
  • GCS of 15 with normal mental status
  • No palpable skull fracture
  • But with: loss of consciousness >5 seconds, severe mechanism of injury, or not acting normally per parent
  • Risk of significant injury ~0.9% 1

CT may be considered over observation in these cases:

• Parental preference
• Multiple risk factors present
• Worsening symptoms during observation
• Young infants where observation is challenging 1

Very Low-Risk Features (CT Not Recommended)

• Children ≥2 years with:
  • GCS of 15
  • Normal mental status
  • No clinical signs of basilar skull fracture
  • No loss of consciousness
  • No vomiting
  • No severe injury mechanism
  • No severe headache
  • Risk of clinically important TBI <0.05% 1, 2
• Children <2 years with:
  • GCS of 15
  • No altered mental status
  • No palpable skull fracture
  • No nonfrontal scalp hematoma
  • No loss of consciousness >5 seconds
  • No severe mechanism of injury
  • Acting normally per parents
  • Risk of clinically important TBI <0.02% 1, 2

Special Considerations

Vascular Imaging

• Not routinely indicated for minor head trauma
• Consider CTA if clinical suspicion for vascular injury exists:
  • Basilar fracture through vascular canal
  • Signs of arterial stroke
  • Fractures extending through skull base vascular channels 1

Subacute Head Trauma (8 days - 1 month post-injury)

• CT indicated for significant change in neurologic status
• MRI may be more helpful for persistent or unexplained neurological deficits
• MRI has superior detection of:
  • Small brainstem/infratentorial hemorrhages
  • Subacute hemorrhage
  • Nonhemorrhagic contusions
  • Ischemia 1

Radiation Concerns

• CT scanning carries risks of radiation-induced malignancy in children 2
• Skull radiographs are insufficient for evaluation of traumatic brain injury as up to 50% of intracranial injuries occur without fracture 1
• Recent studies have challenged the need for routine second brain imaging after TBI 3

Clinical Pitfalls to Avoid

1. Over-reliance on symptoms alone: An abnormal CT scan cannot be reliably ruled out based solely on symptoms in mild head injury 4

2. Underestimating severity in infants: Assessment is more challenging in very young children; consider lower threshold for imaging

3. Delayed presentation: Children requiring neurosurgical intervention after second imaging are more likely to have presented >4 hours after injury 3

4. Missing non-accidental trauma: Children with inflicted injuries may require different management approaches and are more likely to need neurosurgical intervention 3

5. Focusing only on head CT: Consider the need for cervical spine imaging in appropriate cases, especially with severe mechanism of injury

By following these evidence-based guidelines, clinicians can appropriately identify children who require CT imaging while minimizing unnecessary radiation exposure in those at very low risk of clinically important traumatic brain injury.