When is a computed tomography (CT) scan advised for an infant who has fallen?

When to Advise CT Scan for an Infant Fall

For infants under 2 years with minor head trauma, CT scan should be obtained when specific high-risk features are present according to validated clinical decision rules, particularly the PECARN criteria, rather than routinely scanning all infants who fall. 1

Risk Stratification Framework

Very Low Risk - CT NOT Indicated 1

Infants who meet ALL of the following criteria do NOT require CT:

• Normal mental status
• No loss of consciousness
• No vomiting
• No severe mechanism of injury (e.g., not a fall from significant height, not motor vehicle collision)
• No palpable skull fracture
• Acting normally per parent
• Glasgow Coma Scale (GCS) score of 15 1

These very low-risk infants have an extremely low likelihood of clinically important intracranial injury and should not routinely undergo CT. 1

Intermediate Risk - CT May Be Appropriate 1

For infants <2 years with GCS 15 and normal mental status but who have ANY of the following risk factors (estimated 0.9% risk of significant injury):

• Loss of consciousness >5 seconds
• Severe mechanism of injury (fall >3 feet, high-impact collision)
• Not acting normally per parent
• Severe or worsening headache (if assessable)
• Multiple episodes of vomiting 1

CT may be considered in lieu of careful clinical observation based on parental preference, multiple risk factors present simultaneously, worsening symptoms during observation, or when observational assessment is challenging in very young infants. 1

High Risk - CT Strongly Indicated 1

Infants <2 years with ANY of the following (estimated 4.3% risk of clinically important injury):

• GCS <15
• Altered mental status
• Palpable skull fracture
• Signs of basilar skull fracture
• Focal neurological deficits 1

These high-risk infants require immediate non-contrast head CT. 1

Special Consideration: Suspected Child Abuse

For infants ≤24 months being evaluated for suspected physical abuse, clinicians should have a low threshold for performing head CT even without overt neurological symptoms. 1

Key indicators warranting CT in suspected abuse:

• Rib fractures (may be only abnormality in 30% of cases)
• Multiple fractures of different ages
• Facial injury
• Apparently isolated bruises (27% had occult intracranial injury in one study)
• Any discrepancy between injury pattern and reported history 1

In suspected abuse cases, unenhanced CT is the initial study of choice in the emergent setting, with MRI reserved for follow-up or non-emergent evaluation. 1

Critical Counseling Points

When discussing CT decisions with families, address:

• Radiation risk: Pediatric head CT carries lifetime cancer risk, though cumulative risk must be balanced against missing significant injury 1
• Observation alternative: For intermediate-risk infants, careful clinical observation (typically 4-6 hours) is a valid alternative to immediate CT 1
• Return precautions: Families must understand warning signs requiring immediate return: persistent vomiting, worsening headache, altered consciousness, seizures, or abnormal behavior 1

Common Pitfalls to Avoid

• Do not rely on loss of consciousness alone as an indication for CT - it has poor predictive value in isolation 1
• Do not use skull radiographs - up to 50% of intracranial injuries occur without fracture, and radiographs miss significant injuries 1
• Do not assume normal behavior excludes injury - 16% of children with GCS 15 and no loss of consciousness can still have intracranial injury, though most do not require intervention 2
• Do not delay CT in high-risk patients for prolonged observation - immediate imaging is warranted 1

Algorithm Summary

1. Assess GCS and mental status - if <15 or altered, proceed directly to CT 1
2. Examine for palpable skull fracture or basilar skull fracture signs - if present, proceed to CT 1
3. If GCS 15 and normal exam, assess PECARN intermediate risk factors (LOC >5 seconds, severe mechanism, not acting normally, vomiting) 1
4. If no risk factors present - observation without CT is appropriate 1
5. If intermediate risk factors present - shared decision-making regarding CT versus observation, considering parental preference and clinical judgment 1
6. If suspected abuse - lower threshold for CT regardless of symptoms 1