MDCalc Wars – Tiny Patient, Big Decision: Head CT or no Head CT?

Written by Eric Steinberg DO, MEHP
REBEL EM
Medical Category: Trauma
Clinical Decision Tools, infant head injury, Infant Scalp Score, MDCalc, MDCalc Wars, observation vs CT, PECARN, pediatric head injury, pediatric risk stratification, pediatric trauma, scalp hematoma

September 29, 2025

🗝️ Key Points

- 🧠 PECARN = Big Picture Rule
  Validated for all kids with head trauma, helping identify those at very low risk for ciTBI to avoid unnecessary CT scans.
- 👶 Infant Scalp = Baby-Focused Tool
  Specifically designed for infants <2 years with isolated scalp hematomas, adding nuance for age, size, and location.
- 📊 Performance Difference
  PECARN: Extremely sensitive (>99%) for serious injuries but less specific.
  Infant Scalp: Good balance (AUC ~0.80) for this narrow subgroup.
- 🩺 Practical Takeaway
  Use PECARN for initial risk stratification, but when dealing with infants and scalp hematomas, Infant Scalp Scoreoffers extra guidance to decide between observe vs. CT.

🤕 Case

A 6-month-old rolls off the couch, bumps his head, and immediately lets everyone know with a loud cry. Now he’s back to his usual self—smiling, feeding like a champ, and trying to chew on your stethoscope. The only catch: a large, ominous-looking temporal hematoma that makes his parents’ hearts race. They turn to you: “Doc, does our baby need a CT scan?”

📌 Clinical Decision Rules

PECARN has been THE decision rule for guidance on management of kids with head injuries, but the Infant Scalp Score dives even deeper—built just for babies with scalp hematomas. Which rule is best in this situation?

🎯 Quick Hits

💬 Case Resolution

Although our kiddo looked fantastic—smiling, feeding, and charming the staff—the combination of his age, hematoma size, and location tipped the scales toward imaging when the Infant Scalp Score was applied. A CT was performed and, thankfully, came back negative. With a negative scan, he went home happy, leaving his parents more exhausted than he was.

🚨 Clinical Bottom Line

PECARN: well-validated, widely accepted tool to assess head injury risk in children of all ages.
Infant Scalp Score: adds age and hematoma-specific nuance, may be most applicable to children <1 year of age.

Post Peer Reviewed By: Marco Propersi, DO (Twitter/X: @Marco_Propersi), and Mark Ramzy, DO (X: @MRamzyDO)