Canadian CT Head Rule (Stiell 2001)
Canadian CT Head Rule (Stiell 2001). CT is indicated if any high-risk factor (GCS <15 at 2 hours, suspected open or depressed skull fracture, any sign of basal skull fracture, vomiting 2 or more times, or age 65 or older) or any medium-risk factor (amnesia before impact >30 min, or dangerous mechanism as assigned by the caller). Not a diagnosis, not NEXUS, not PECARN, not CATCH, and not pediatric. magent does not examine the patient.
Asked 1.4x its listed price for its own exampleour last check, 2026-09-28
1 of 1checks answered this week
317 msmedian answer time
$0.005listed price per call
$0.007price it asked us
Paid test badge: not yet. The checks above are free: we call the tool without paying and read the payment request it sends back. The Verified badge needs paid calls whose answers match the promised output, and nobody can buy a badge.
Endpoint
POST https://api.magentlab.com/api/calc/canadian_ct_head
| Category | Everything else |
|---|---|
| Provider host | api.magentlab.com |
| Networks | eip155:8453 |
| Payment schemes | exact |
| Self-reported calls, 30 days | 0 from 0 payers (the provider's figure, not ours) |
Our checks, last 30 days
| Day | Result | HTTP | Asked | Time |
|---|---|---|---|---|
| 2026-09-28 | valid payment request | 402 | $0.007 | 317 ms |
Example input (from the provider)
{
"body": {
"items": [
{
"age": 40,
"amnesia_before_impact_gt_30min": false,
"any_sign_basal_skull_fx": false,
"dangerous_mechanism": false,
"gcs_lt_15_at_2h": false,
"suspected_open_or_depressed_skull_fx": false,
"vomiting_two_or_more": false
},
{
"age": 40,
"amnesia_before_impact_gt_30min": false,
"any_sign_basal_skull_fx": false,
"dangerous_mechanism": false,
"gcs_lt_15_at_2h": false,
"suspected_open_or_depressed_skull_fx": false,
"vomiting_two_or_more": false
}
]
},
"method": "POST",
"type": "http"
}
Promised output schema (from the provider)
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"body": {
"additionalProperties": false,
"properties": {
"items": {
"items": {
"properties": {
"age": {
"description": "Age in years (16-120). Age \u226565 is a high-risk factor that indicates CT; 64 does not. The published rule is for patients \u226516 years.",
"type": "integer"
},
"amnesia_before_impact_gt_30min": {
"description": "Amnesia before impact of more than 30 minutes. true or false as assigned by the caller. Medium-risk.",
"type": "boolean"
},
"any_sign_basal_skull_fx": {
"description": "Any sign of basal skull fracture (hemotympanum, raccoon eyes, CSF otorrhea/rhinorrhea, or Battle's sign). true or false as assigned by the caller. High-risk.",
"type": "boolean"
},
"dangerous_mechanism": {
"description": "Dangerous mechanism as assigned by the caller. true or false. Medium-risk. Published list: pedestrian struck by a motor vehicle, occupant ejected from a motor vehicle, fall from elevation >3 feet or 5 stairs. magent does not classify mechanism.",
"type": "boolean"
},
"gcs_lt_15_at_2h": {
"description": "GCS <15 at 2 hours after injury. true or false as assigned by the caller. High-risk. magent does not take a GCS integer.",
"type": "boolean"
},
"suspected_open_or_depressed_skull_fx": {
"description": "Suspected open or depressed skull fracture. true or false as assigned by the caller. High-risk.",
"type": "boolean"
},
"vomiting_two_or_more": {
"description": "Two or more episodes of vomiting. true or false as assigned by the caller. High-risk.",
"type": "boolean"
}
},
"required": [
"age",
"gcs_lt_15_at_2h",
"suspected_open_or_depressed_skull_fx",
"any_sign_basal_skull_fx",
"vomiting_two_or_more",
"amnesia_before_impact_gt_30min",
"dangerous_mechanism"
],
"type": "object"
},
"maxItems": 25,
"minItems": 1,
"type": "array"
}
},
"required": [
"items"
],
"type": "object"
},
"headers": {
"additionalProperties": {
"type": "string"
},
"type": "object"
},
"method": {
"const": "POST",
"type": "string"
},
"type": {
"const": "http",
"type": "string"
}
},
"required": [
"type",
"method"
],
"type": "object"
},
"output": {
"properties": {
"example": {
"type": "object"
},
"type": {
"type": "string"
}
},
"required": [
"type"
],
"type": "object"
}
},
"required": [
"input"
],
"type": "object"
}