The Canadian CT Head Rule (CCHR) is 100% sensitive for predicting the need for neurosurgical intervention in minor head injury.
Imaging Classification
Observation Safe
Low Risk Profile
Clinical Sentiment
"The probability of a clinically significant brain injury is extremely low (<1%). Clinical observation without imaging is appropriate based on the Canadian Rule."
Validated TBI Screening Framework.
Guidelines & Evidence
Clinical Details
Section 1
When to Use
When to Use
Evaluating adults (16–64) with minor head injury (GCS 13–15).
Inclusion: Witnessed LOC, amnesia, or confusion.
Exclusion: GCS < 13, age < 16, bleeding disorders, obvious open fracture.
Signs of basal skull fracture (e.g., raccoon eyes, Battle's sign).
Vomiting ≥ 2 episodes.
Age ≥ 65 years.
Medium-Risk Criteria (Any = CT Indicated)
Amnesia before impact > 30 minutes.
Dangerous mechanism (e.g., pedestrian vs. vehicle, fall > 3ft/5 stairs).
Section 3
Pearls/Pitfalls
High Specificity
The Canadian CT Head Rule is distinguished by its high specificity for neurosurgical intervention. Unlike the New Orleans Criteria, it effectively filters out patients who may have minor CT findings but will never require surgery, making it the preferred rule for resource-limited settings.
Section 4
Evidence Appraisal
Primary Reference
The Canadian CT Head Rule for patients with minor head injury
Stiell IG et al. • Lancet. 2001;357(9266):1391-1396
Developed by researchers at the University of Ottawa Emergency Department to safely reduce unnecessary CT scanning in minor head injury while maintaining 100% sensitivity for neurosurgical intervention. It is widely adopted by emergency medicine guidelines (NICE, ACEP).
