Minor Head Injury — CT Decision
Canadian CT Head Rule — High and Medium Risk Criteria
The Canadian CT Head Rule (CCHR) identifies minor head injury patients who require CT for neurosurgical intervention (high-risk criteria) or brain injury on CT (medium-risk criteria). It is validated for adults with GCS 13–15 and at least one of: loss of consciousness, amnesia, or witnessed disorientation. When all six criteria are absent, CT is not required — safely reducing unnecessary imaging by up to 36% without missing significant injuries. The CCHR was prospectively validated in 3,121 patients and subsequently validated in multiple external cohorts.
Pathway Steps
Confirm Minor Head Injury Criteria
The CCHR applies only to this specific patient population
Canadian CT Head Rule
Check ALL criteria that apply — ANY criterion present = CT indicated
Clinical Disclaimer
The Canadian CT Head Rule applies ONLY to patients with GCS 13–15 and at least one of: witnessed loss of consciousness, amnesia for events, or observed disorientation. It is NOT applicable to patients with GCS < 13, coagulopathy, seizure post-injury, focal neurological deficits, or pediatric patients (under 16). Clinical judgment supersedes algorithmic guidance in all cases.