Plain Skull Radiographs Are NOT Indicated for Infants with Minor Head Trauma
Plain skull radiographs should not be routinely ordered for an infant who fell and hit his head, as they are insufficient to evaluate for traumatic brain injury and up to 50% of intracranial injuries occur without skull fracture. 1
Risk Stratification Using PECARN Criteria
The first step is to apply the validated PECARN clinical decision rule to determine the infant's risk level for clinically important traumatic brain injury:
Very Low Risk (No Imaging Needed)
For infants <2 years with GCS of 15 and NONE of the following:
- Altered mental status
- Palpable skull fracture
- Nonfrontal scalp hematoma
- Loss of consciousness >5 seconds
- Severe mechanism of injury
- Not acting normally per parents
These infants can safely forgo any imaging with <0.02% risk of clinically important traumatic brain injury (100% sensitivity, 100% NPV). 1
Intermediate Risk (Consider CT vs. Observation)
Infants <2 years with GCS of 15, normal mental status, no palpable skull fracture, BUT with:
- Loss of consciousness >5 seconds
- Severe mechanism of injury
- Not acting normally per parent
Risk of significant injury is approximately 0.9%. CT may be considered instead of observation based on parental preference, multiple risk factors, worsening symptoms, or difficulty with clinical observation in young infants. 1
High Risk (CT Strongly Recommended)
Infants <2 years with:
- GCS of 14
- Altered mental status
- Palpable skull fracture
Risk of clinically significant intracranial injury is approximately 4.4%. CT head without contrast is strongly recommended due to substantial risk of intervene-able injury. 1
Why Skull Radiographs Are Inadequate
The evidence is clear and consistent across multiple guidelines:
- Up to 50% of intracranial injuries in children occur without skull fracture 1
- Skull radiographs cannot detect intracranial hemorrhage, edema, or midline shift 2
- Sensitivity for skull fracture is only 63% 2
- Severe intracranial injury can occur in the absence of skull fracture 3
The CDC explicitly states: "Skull radiographs should not be used in the diagnosis of pediatric mTBI" and "should not be used in the screening for intracranial injury" (high recommendation, level B evidence). 2
Limited Exception for Skull Radiographs
The only scenario where skull radiographs may have utility is when:
- Non-accidental injury is suspected
- A depressed or penetrating skull fracture needs confirmation
- CT is not immediately available and a skull fracture finding would change management (e.g., prompting transfer for CT)
Even in these cases, if intracranial injury is suspected, proceed directly to CT rather than skull radiograph. 2, 3
Common Pitfalls to Avoid
- Do not order skull X-rays reflexively for all infant head injuries—this exposes the child to unnecessary radiation without providing clinically useful information about intracranial injury
- Do not assume absence of skull fracture on X-ray excludes intracranial injury—this false reassurance can be dangerous
- Do not use skull X-rays as a "screening test" before deciding on CT—if CT is indicated by PECARN criteria, proceed directly to CT
- Do not forget that clinical examination trumps imaging—a neurologically normal infant meeting very low-risk PECARN criteria needs no imaging at all
Practical Algorithm
- Apply PECARN criteria to stratify risk
- Very low risk → No imaging, clinical observation
- Intermediate risk → Shared decision-making regarding CT vs. observation
- High risk → CT head without contrast
- Skull radiographs → Reserved only for suspected non-accidental injury or when specifically evaluating for depressed/penetrating fracture
The ACR Appropriateness Criteria (2020) consistently rates skull radiography as "usually not appropriate" across all variants of pediatric head trauma, while CT head receives the highest appropriateness rating when imaging is indicated. 1