{"uid":"cap_RAmLfmRFF6TzQy9nih2Ui","slug":"chalice-pediatric-head-ct-decision-rule-magent-afcdcdca","name":"CHALICE Pediatric Head CT Decision Rule (magent)","description":"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.","url":"https://api.magentlab.com/api/calc/chalice","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET","HEAD","DELETE"],"type":"string"},"headers":{"type":"object","additionalProperties":{"type":"string"}},"queryParams":{"type":"object","required":["age","gcs","loc_gt_5_min","amnesia_gt_5_min","abnormal_drowsiness","vomits_ge_3","suspicion_nai","seizure_no_epilepsy","penetrating_depressed_or_tense_fontanelle","basal_skull_fracture","focal_neurology","bruise_swelling_laceration_gt_5cm","high_speed_rta","fall_gt_3m","high_speed_projectile_or_object"],"properties":{"age":{"type":"integer","description":"Age in whole years (0-15). CHALICE is for children younger than 16. Age 0 is younger than 1 year (GCS <15 and bruise >5 cm apply). Age 1-15 uses GCS <14. Age 16 is rejected."},"gcs":{"type":"integer","description":"Glasgow Coma Scale total, integer 3-15 as assigned by the caller. Examination criterion: GCS <14, or GCS <15 if age <1 year."},"fall_gt_3m":{"type":"boolean","description":"Fall >3 m as assigned by the caller. true or false. Mechanism criterion. magent does not classify mechanism or take a height integer."},"vomits_ge_3":{"type":"boolean","description":"Three or more vomits after the head injury. true or false as assigned by the caller. History criterion."},"loc_gt_5_min":{"type":"boolean","description":"Witnessed loss of consciousness >5 minutes. true or false as assigned by the caller. History criterion. magent does not take a duration integer."},"suspicion_nai":{"type":"boolean","description":"Suspicion of non-accidental injury as assigned by the caller. true or false. History criterion. magent does not diagnose NAI."},"high_speed_rta":{"type":"boolean","description":"High-speed road traffic accident as occupant, pedestrian, or cyclist as assigned by the caller (paper: speed >40 mph). true or false. Mechanism criterion. magent does not classify mechanism."},"focal_neurology":{"type":"boolean","description":"Positive focal neurology. true or false as assigned by the caller. Examination criterion. magent does not examine the child."},"amnesia_gt_5_min":{"type":"boolean","description":"Amnesia (anterograde or retrograde) >5 minutes. true or false as assigned by the caller. History criterion. magent does not take a duration integer."},"abnormal_drowsiness":{"type":"boolean","description":"Abnormal drowsiness. true or false as assigned by the caller. History criterion. magent does not examine the child."},"seizure_no_epilepsy":{"type":"boolean","description":"Seizure after the head injury in a child with no history of epilepsy. true or false as assigned by the caller. History criterion."},"basal_skull_fracture":{"type":"boolean","description":"Signs of basal skull fracture. true or false as assigned by the caller. Examination criterion. magent does not examine the child."},"high_speed_projectile_or_object":{"type":"boolean","description":"High-speed injury from a projectile or object as assigned by the caller. true or false. Mechanism criterion. magent does not classify mechanism."},"bruise_swelling_laceration_gt_5cm":{"type":"boolean","description":"Bruise, swelling, or laceration >5 cm. true or false as assigned by the caller. Examination criterion that scores only when age <1 year; parsed but not scored when age >= 1. magent does not measure the lesion."},"penetrating_depressed_or_tense_fontanelle":{"type":"boolean","description":"Suspicion of penetrating or depressed skull injury or tense fontanelle. true or false as assigned by the caller. Examination criterion. magent does not examine the child."}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object"}}}}},"responseSchema":{"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}]}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.005","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"probe","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.005/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.005","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.005","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_kQCuRyYFDSN-WmX5Q7KEn","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.005","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Applies the CHALICE clinical decision rule to determine if CT imaging is required for a child (ages 0–15) following a head injury","exampleAgentPrompt":"Using the CHALICE rule, does a 4-year-old with a GCS of 13 need a CT after falling about 4 meters? No vomiting, no loss of consciousness, no seizure, no amnesia, no NAI suspicion, no focal neurology, no skull signs, no projectile, no high-speed RTA.","exampleUseCases":[{"title":"Post-fall triage for toddler","prompt":"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."},{"title":"High-speed RTA pediatric passenger","prompt":"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?"},{"title":"Infant with scalp swelling after impact","prompt":"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?"}],"resultDescription":"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.","failureModes":["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"],"whenToPreferThis":"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.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-15T01:19:45.941Z","isFirstParty":false}