Emergency · LIVE

CHALICE pediatric head CT

CHALICE

Apply the Dunning 2006 CHALICE rule and return whether CT is required from caller-assigned history, examination, and mechanism findings after head injury in a child younger than 16.

LIVE $0.005 USDC GET /api/calc/chalice

Markdown: /docs/chalice.md · Canonical: https://magentlab.com/docs/chalice

Not a medical device. Not a diagnosis, dose, or listing recommendation.

What it computes

Apply the Dunning 2006 CHALICE rule and return whether CT is required from caller-assigned history, examination, and mechanism findings after head injury in a child younger than 16.

When to use

When an agent has caller-assigned findings after head injury in a child 0-15 years and needs the Dunning 2006 CHALICE CT rule, not PECARN, CATCH, or Canadian CT Head.

When not to use

• Not a medical device. Not a diagnosis. magent does not examine the child.
• This tool is the Dunning 2006 CHALICE rule only. It is not PECARN, not CATCH, and not the Canadian CT Head Rule.
• Age is integer years 0-15 (children younger than 16). GCS is an integer 3-15 as assigned by the caller.
• The GCS criterion is GCS <14, or GCS <15 if age <1 year. Bruise, swelling, or laceration >5 cm requires CT only when age <1 year; the flag is parsed but does not score at age 1-15.
• Mechanism findings are caller-assigned (paper: high-speed RTA >40 mph as occupant, pedestrian, or cyclist; fall >3 m; high-speed injury from a projectile or object). magent does not classify mechanism.
• Suspicion of non-accidental injury is caller-assigned. magent does not diagnose NAI.

Formula

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.

Citation

Title

Derivation of the children's head injury algorithm for the prediction of important clinical events decision rule for head injury in children

Authors

Dunning J, Daly JP, Lomas JP, Lecky F, Batchelor J, Mackway-Jones K

Source

Arch Dis Child. 2006;91(11):885-891

DOI

10.1136/adc.2005.083980

Worked example

Also searched as

• CHALICE
• children's head injury algorithm
• Dunning 2006
• CHALICE head CT
• pediatric CHALICE rule
• Children's Head injury ALgorithm for the prediction of Important Clinical Events
• CHALICE CT rule
• Dunning CHALICE

Try

Opens the live endpoint. Unpaid browser requests show the paywall; agents should send Accept: application/json.

/api/calc/chalice?age=10&gcs=15&loc_gt_5_min=false&amnesia_gt_5_min=false&abnormal_drowsiness=false&vomits_ge_3=false&suspicion_nai=false&seizure_no_epilepsy=false&penetrating_depressed_or_tense_fontanelle=false&basal_skull_fracture=false&focal_neurology=false&bruise_swelling_laceration_gt_5cm=false&high_speed_rta=false&fall_gt_3m=false&high_speed_projectile_or_object=false

Full URL: https://api.magentlab.com/api/calc/chalice?age=10&gcs=15&loc_gt_5_min=false&amnesia_gt_5_min=false&abnormal_drowsiness=false&vomits_ge_3=false&suspicion_nai=false&seizure_no_epilepsy=false&penetrating_depressed_or_tense_fontanelle=false&basal_skull_fracture=false&focal_neurology=false&bruise_swelling_laceration_gt_5cm=false&high_speed_rta=false&fall_gt_3m=false&high_speed_projectile_or_object=false

Call

Expect HTTP 402 until you retry with PAYMENT-SIGNATURE. Incomplete query params return HTTP 400 before any quote or charge.

curl -i -H "Accept: application/json" "https://api.magentlab.com/api/calc/chalice?age=10&gcs=15&loc_gt_5_min=false&amnesia_gt_5_min=false&abnormal_drowsiness=false&vomits_ge_3=false&suspicion_nai=false&seizure_no_epilepsy=false&penetrating_depressed_or_tense_fontanelle=false&basal_skull_fracture=false&focal_neurology=false&bruise_swelling_laceration_gt_5cm=false&high_speed_rta=false&fall_gt_3m=false&high_speed_projectile_or_object=false"

Parameters

Bulk (POST)

POST the same path with a JSON items array. The first item is the GET unit; each additional item is $0.002. Invalid items return HTTP 400 before settlement.

POST /api/calc/chalice Max 25 unit_amount + extra_item_amount * (n - 1) extra $0.002 PREVIEW

• 1 to 25 items. Each item uses the same keys as the GET query parameters.
• POST of 1 item costs the same as GET. Lists longer than 25: chunk into multiple POSTs. Extra items still execute; do not pad dummy rows.
• The first invalid item fails the whole request (index in the 400 JSON). You are not charged.
• HTTP 200 is {count, path, items}. Each items[i] is the GET 200 body for that row.
• Catalog misses (empty matches, found=false) stay paid 200s inside that slot.
• x402 resource URL is this path plus n and body_sha256. Browsers that prefer text/html get the same paywall as GET; Pay retries POST with the same items.

Example request (fixture)

{
  "items": [
    {
      "abnormal_drowsiness": "false",
      "age": "10",
      "amnesia_gt_5_min": "false",
      "basal_skull_fracture": "false",
      "bruise_swelling_laceration_gt_5cm": "false",
      "fall_gt_3m": "false",
      "focal_neurology": "false",
      "gcs": "15",
      "high_speed_projectile_or_object": "false",
      "high_speed_rta": "false",
      "loc_gt_5_min": "false",
      "penetrating_depressed_or_tense_fontanelle": "false",
      "seizure_no_epilepsy": "false",
      "suspicion_nai": "false",
      "vomits_ge_3": "false"
    },
    {
      "abnormal_drowsiness": "false",
      "age": "10",
      "amnesia_gt_5_min": "false",
      "basal_skull_fracture": "false",
      "bruise_swelling_laceration_gt_5cm": "false",
      "fall_gt_3m": "false",
      "focal_neurology": "false",
      "gcs": "15",
      "high_speed_projectile_or_object": "false",
      "high_speed_rta": "false",
      "loc_gt_5_min": "false",
      "penetrating_depressed_or_tense_fontanelle": "false",
      "seizure_no_epilepsy": "false",
      "suspicion_nai": "false",
      "vomits_ge_3": "false"
    }
  ]
}

Open bulk paywall →

Opens a two-item fixture on the API host. Unpaid browsers get the same MetaMask paywall as GET; Pay retries POST with those items.

Example 200 (fixture)

{
  "count": 2,
  "path": "/api/calc/chalice",
  "items": [
    {
      "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.",
      "citation": {
        "authors": "Dunning J, Daly JP, Lomas JP, Lecky F, Batchelor J, Mackway-Jones K",
        "doi": "10.1136/adc.2005.083980",
        "id": "dunning-2006",
        "pmid": "17056862",
        "source": "Arch Dis Child. 2006;91(11):885-891",
        "title": "Derivation of the children's head injury algorithm for the prediction of important clinical events decision rule for head injury in children"
      },
      "formula": "chalice",
      "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.",
      "age_years": 10,
      "criteria": [
        {
          "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",
          "met": false
        }
      ],
      "chalice_ct_required": false,
      "chalice_low_risk": true,
      "gcs": 15
    },
    {
      "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.",
      "citation": {
        "authors": "Dunning J, Daly JP, Lomas JP, Lecky F, Batchelor J, Mackway-Jones K",
        "doi": "10.1136/adc.2005.083980",
        "id": "dunning-2006",
        "pmid": "17056862",
        "source": "Arch Dis Child. 2006;91(11):885-891",
        "title": "Derivation of the children's head injury algorithm for the prediction of important clinical events decision rule for head injury in children"
      },
      "formula": "chalice",
      "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.",
      "age_years": 10,
      "criteria": [
        {
          "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",
          "met": false
        }
      ],
      "chalice_ct_required": false,
      "chalice_low_risk": true,
      "gcs": 15
    }
  ]
}

Response

Example JSON

Machine form of the same example. Frozen fixture. Not a live lookup.

{
  "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.",
  "citation": {
    "authors": "Dunning J, Daly JP, Lomas JP, Lecky F, Batchelor J, Mackway-Jones K",
    "doi": "10.1136/adc.2005.083980",
    "id": "dunning-2006",
    "pmid": "17056862",
    "source": "Arch Dis Child. 2006;91(11):885-891",
    "title": "Derivation of the children's head injury algorithm for the prediction of important clinical events decision rule for head injury in children"
  },
  "formula": "chalice",
  "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.",
  "age_years": 10,
  "criteria": [
    {
      "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",
      "met": false
    }
  ],
  "chalice_ct_required": false,
  "chalice_low_risk": true,
  "gcs": 15
}

Client errors (HTTP 400)

Invalid params return 400 without charge. Shared HTTP 402 and 503 meanings: Payments.

Related tools

• PECARN pediatric head CT — Apply the Kuppermann 2009 PECARN prediction trees and return high, intermediate, or low risk of clinically important brain injury from caller-assigned findings after pediatric head trauma.
• CATCH — Apply the Osmond 2010 CATCH derivation and return high, medium, or low risk plus whether CT of the head is indicated from seven caller-assigned findings after pediatric minor head injury.
• Canadian CT Head Rule — Apply the Stiell 2001 Canadian CT Head Rule and return whether CT is indicated from caller-assigned high-risk and medium-risk findings after minor blunt head injury.

Payment

Unpaid requests return HTTP 402 even if query parameters or POST items are missing or invalid, so CDP and agents can index the path. After a PAYMENT-SIGNATURE, invalid params return HTTP 400 JSON before settlement. magent does not charge. Fix the params, then request a new 402 quote for that complete URL. Catalog misses (empty matches, found=false) are valid paid 200s. Unpaid valid requests return HTTP 402 with a base64 PAYMENT-REQUIRED header. HTTP 503 is not a new quote: retry the same PAYMENT-SIGNATURE. Full handshake and shared payment errors: Payments. Stdio MCP: /docs/mcp.

Guarantees

• HTTP 402 is unpaid, including a missing query. After PAYMENT-SIGNATURE, invalid parameters return HTTP 400 before settlement. You are not charged.
• exact: settlement finishes before the tool (paymentFlow upfront). batch-settlement: verify/deposit before the tool; chargedCumulativeAmount commits after HTTP 2xx. Uncertain or failed settlement fails closed (HTTP 503). Retry the same PAYMENT-SIGNATURE.
• HTTP 402 is unpaid only. Do not sign a second authorization because of a 503.
• Execution is timeout-bounded and concurrency-capped.
• Calculator inputs are stored encrypted for allowlisted operators (Magent Console). They are not in public logs, SSH lookups, catalog, or rollups. Request logs store path without query.