Emergency & trauma

Canadian CT Head Rule

High- and medium-risk criteria for CT after minor head injury.

Intended population: Age 16 or older, blunt head injury within 24 hours, initial GCS 13–15, and post-traumatic loss of consciousness, amnesia, or disorientation.

All responses must reflect a clinician's verified history and examination. An unassessed finding is not an absent finding.
A negative rule does not address other causes of collapse or determine safe discharge.

Age (years)

Meets every inclusion criterion in the population above?

Primary syncope/seizure or unclear trauma history; anticoagulation, antiplatelet therapy other than aspirin alone, bleeding disorder, post-traumatic seizure, focal deficit, penetrating/obvious depressed fracture, unstable major trauma, pregnancy, or repeat assessment?

GCS below 15 at 2 hours after injury?

Suspected open or depressed skull fracture?

Basilar fracture signs: hemotympanum, CSF leak, raccoon eyes, or Battle sign?

At least 2 vomiting episodes?

At least 30 minutes of amnesia before impact?

Pedestrian struck, vehicle occupant ejected, or fall >3 feet / 5 stairs?

Sources and scoring references

Original CCHR study (2001) ↗ACEP mild traumatic brain injury policy (2023) ↗

Implementation references reviewed October 28, 2026. Verify applicability and unusual or treatment-changing results against the linked references and local guidance.