CanadiEM MVP Infographic Series - Canadian CT Head Rule

CanadiEM MVP Infographic Series – Canadian CT Head Rule

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The Canadian CT Head Rule for Patients with Minor Head Injuries

As part of the CanadiEM MVP Infographic Series, this post reviews The Canadian CT Head Rule for Patients with Minor Head Injuries​1​. This article developed a highly sensitive algorithm to aid clinicians in deciding whether patients presenting with minor head injuries should undergo a CT scan.

Prior to this study, recommendations for imaging a minor head injury conflicted. This made it difficult for physicians to determine which patients were at higher risk for developing intracranial hematoma. Therefore, patients were extensively over-imaged, as only 0.7-3.7% of patients were found to have intracranial pathology on CT scans. Consequently, many patients were being exposed to unnecessary radiation, and healthcare resources were over-utilized to fund the scans.

Using a prospective cohort study in 10 Canadian hospitals, Stiell et al. determined high risk features for identifying minor head injury patients with potential intracranial pathology. A standardized assessment was performed on eligible patients to assess for features that could group patients into risk categories. The high risk category suggested patients could need neurological intervention, while medium risk grouped patients likely to have a brain injury present on CT scan. Subsequently, data analysis revealed multiple features on history and physical exam with strong correlation to the high and medium risk outcomes. These features are discussed on the infographic.

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This post was peer reviewed by Alvin Chin and uploaded by Andy Tolmie


  1. 1.
    Stiell IG, Wells GA, Vandemheen K, et al. The Canadian CT Head Rule for patients with minor head injury. The Lancet. May 2001:1391-1396. doi:10.1016/s0140-6736(00)04561-x

Andrew Tolmie

Andrew is a PGY-1 at the University of Saskatchewan Emergency Medicine Program. He is also a Graphic Design Lead for the CanadiEM Infographics team. Outside of medicine, Andrew enjoys pour-over coffee, downhill skiing, and mountain biking.
Alvin is currently a PGY5 in the FRCP EM program at McMaster University. He serves as Director of Design for CanadiEM and has interests in knowledge translation and health innovation.