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CHALICE Pediatric Head CT Decision Rule (magent)
x402
CHALICE Pediatric Head CT Decision Rule (magent) is a paid API for AI agents from api.magentlab.com, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-15).
Applies the CHALICE clinical decision rule to determine if CT imaging is required for a child (ages 0–15) following a head injury
Price / call$0.005
Success—
StatusUnknown
How this service works
CHALICE (Dunning 2006). CT required in children 0-15 if any history, exam, or mechanism criterion is present; else low risk. GCS <14, or GCS <15 if age <1 year. Bruise/swelling/laceration >5 cm only if age <1 year. Mechanism is caller-assigned (paper: high-speed RTA >40 mph as occupant/pedestrian/cyclist; fall >3 m; high-speed projectile or object). NAI is caller-assigned. Not PECARN, CATCH, or Canadian CT Head. magent does not examine the child. Not a diagnosis or medical device.
Output
Returns a CHALICE rule result indicating whether CT is required or the child is low risk, based on which history, examination, or mechanism criteria are present. Identifies which specific criterion triggered the CT recommendation, if any.
Example use cases
Post-fall triage for toddler
“A 2-year-old fell off a bunk bed — the parents say she didn't lose consciousness, hasn't vomited, GCS looks normal at 15, no bruising over 5 cm, and no signs of skull fracture. Run the CHALICE rule to see if she needs a head CT.”
High-speed RTA pediatric passenger
“A 9-year-old was in a high-speed car crash. GCS is 14, no vomiting, no amnesia, no seizure, no focal neurology, no skull signs, no NAI suspicion, no fall or projectile. Does CHALICE say he needs a CT?”
Infant with scalp swelling after impact
“An 8-month-old (age 0) hit his head on a table edge — there's a swelling larger than 5 cm on his scalp, GCS appears normal but he's under 1 year old, no vomiting, no loss of consciousness, no NAI suspicion. What does CHALICE say about CT?”
Technical details
Endpoint
GEThttps://api.magentlab.com/api/calc/chaliceWhen to prefer
Use this endpoint when you need to apply the CHALICE (Dunning 2006) clinical decision rule specifically, for a patient aged 0–15 after a head injury, and your caller has already assessed and categorised the clinical flags. Prefer this over PECARN or CATCH when the clinical workflow specifies CHALICE. It is not a substitute for clinical examination and cannot examine the patient.
Side effects
- Age 16 or above is rejected — CHALICE applies only to children under 16
- Invalid GCS values outside 3–15 range will be rejected
- Missing required boolean flags will cause a validation error
- Caller-assigned flags (NAI, mechanism) may reflect inaccurate history — garbage in, garbage out
- Does not replace clinical judgment; result is a calculation aid, not a diagnosis
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object | |
| output | object |
Output
Schema · Response
{
"type": "json",
"example": {
"path": "/api/calc/chalice",
"count": 2,
"items": [
{
"gcs": 15,
"formula": "chalice",
"citation": {
"id": "dunning-2006",
"doi": "10.1136/adc.2005.083980",
"pmid": "17056862",
"title": "Derivation of the children's head injury algorithm for the prediction of important clinical events decision rule for head injury in children",
"source": "Arch Dis Child. 2006;91(11):885-891",
"authors": "Dunning J, Daly JP, Lomas JP, Lecky F, Batchelor J, Mackway-Jones K"
},
"criteria": [
{
"met": false,
"factor": "loc_gt_5_min"
},
{
"met": false,
"factor": "amnesia_gt_5_min"
},
{
"met": false,
"factor": "abnormal_drowsiness"
},
{
"met": false,
"factor": "vomits_ge_3"
},
{
"met": false,
"factor": "suspicion_nai"
},
{
"met": false,
"factor": "seizure_no_epilepsy"
},
{
"met": false,
"value": 15,
"factor": "gcs_criterion"
},
{
"met": false,
"factor": "penetrating_depressed_or_tense_fontanelle"
},
{
"met": false,
"factor": "basal_skull_fracture"
},
{
"met": false,
"factor": "focal_neurology"
},
{
"met": false,
"value": 10,
"factor": "bruise_swelling_laceration_gt_5cm"
},
{
"met": false,
"factor": "high_speed_rta"
},
{
"met": false,
"factor": "fall_gt_3m"
},
{
"met": false,
"factor": "high_speed_projectile_or_object"
}
],
"age_years": 10,
"disclaimer": "Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.",
"chalice_low_risk": true,
"formula_expression": "CT required if any history, examination, or mechanism criterion is present; else low risk. GCS <14, or GCS <15 if age <1 year. Bruise, swelling, or laceration >5 cm only if age <1 year. Mechanism is caller-assigned.",
"chalice_ct_required": false
},
{
"gcs": 15,
"formula": "chalice",
"citation": {
"id": "dunning-2006",
"doi": "10.1136/adc.2005.083980",
"pmid": "17056862",
"title": "Derivation of the children's head injury algorithm for the prediction of important clinical events decision rule for head injury in children",
"source": "Arch Dis Child. 2006;91(11):885-891",
"authors": "Dunning J, Daly JP, Lomas JP, Lecky F, Batchelor J, Mackway-Jones K"
},
"criteria": [
{
"met": false,
"factor": "loc_gt_5_min"
},
{
"met": false,
"factor": "amnesia_gt_5_min"
},
{
"met": false,
"factor": "abnormal_drowsiness"
},
{
"met": false,
"factor": "vomits_ge_3"
},
{
"met": false,
"factor": "suspicion_nai"
},
{
"met": false,
"factor": "seizure_no_epilepsy"
},
{
"met": false,
"value": 15,
"factor": "gcs_criterion"
},
{
"met": false,
"factor": "penetrating_depressed_or_tense_fontanelle"
},
{
"met": false,
"factor": "basal_skull_fracture"
},
{
"met": false,
"factor": "focal_neurology"
},
{
"met": false,
"value": 10,
"factor": "bruise_swelling_laceration_gt_5cm"
},
{
"met": false,
"factor": "high_speed_rta"
},
{
"met": false,
"factor": "fall_gt_3m"
},
{
"met": false,
"factor": "high_speed_projectile_or_object"
}
],
"age_years": 10,
"disclaimer": "Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.",
"chalice_low_risk": true,
"formula_expression": "CT required if any history, examination, or mechanism criterion is present; else low risk. GCS <14, or GCS <15 if age <1 year. Bruise, swelling, or laceration >5 cm only if age <1 year. Mechanism is caller-assigned.",
"chalice_ct_required": false
}
]
}
}Tags
x402
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