{"uid":"cap_KWrvxylHQnh_Ga9M61XI-","slug":"nexus-head-ct-rule-calculator-mower-2017-e5001188","name":"NEXUS Head CT Rule Calculator (Mower 2017)","description":"NEXUS Head CT (Mower 2017). Low-risk, and CT may be omitted by this instrument, only when all eight are absent: age 65 or older, evidence of skull fracture, scalp hematoma, neurologic deficit, altered alertness, abnormal behavior, coagulopathy, and persistent vomiting. Age 65 is high-risk; age 64 is not on age alone. Not a diagnosis, not a CT order, not Hoffman 2000 NEXUS C-spine, and not the Canadian CT Head Rule. magent does not examine the patient.","url":"https://api.magentlab.com/api/calc/nexus_head_ct","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","skull_fracture","scalp_hematoma","neurologic_deficit","altered_alertness","abnormal_behavior","coagulopathy","persistent_vomiting"],"properties":{"age":{"type":"integer","description":"Age in years (integer 18-120). Age ≥ 65 is a high-risk criterion; 64 is not high-risk on age alone. Low-risk age criterion holds when age < 65."},"coagulopathy":{"type":"boolean","description":"Coagulopathy as assigned by the caller. true means coagulopathy is present and low_risk is false. true or false. magent does not interpret a coagulation assay."},"scalp_hematoma":{"type":"boolean","description":"Scalp hematoma as assigned by the caller. true means a scalp hematoma is present and low_risk is false. true or false. magent does not examine the scalp."},"skull_fracture":{"type":"boolean","description":"Evidence of skull fracture as assigned by the caller. true means a skull-fracture finding is present and low_risk is false. true or false. magent does not examine the patient or read a radiograph."},"abnormal_behavior":{"type":"boolean","description":"Abnormal behavior as assigned by the caller. true means abnormal behavior is present and low_risk is false. true or false. magent does not examine the patient."},"altered_alertness":{"type":"boolean","description":"Altered level of alertness as assigned by the caller. true means alertness is altered and low_risk is false. true or false. magent does not assign GCS."},"neurologic_deficit":{"type":"boolean","description":"Neurologic deficit (neurosurgical deficits) as assigned by the caller. true means a deficit is present and low_risk is false. true or false. magent does not examine the patient."},"persistent_vomiting":{"type":"boolean","description":"Persistent vomiting as assigned by the caller. true means persistent vomiting is present and low_risk is false. true or false. magent does not take a vomit count."}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object"}}}}},"responseSchema":null,"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_dzcmlpyeDzqJu_Fa0R36D","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 NEXUS Head CT instrument to determine whether a head CT may be safely omitted based on eight clinical criteria","exampleAgentPrompt":"Run the NEXUS Head CT rule on a 58-year-old patient with no skull fracture, no scalp hematoma, no neurologic deficit, alert and behaving normally, no coagulopathy, and no persistent vomiting — tell me if head CT can be omitted.","exampleUseCases":[{"title":"ED triage after minor head injury","prompt":"I have a 72-year-old patient in the ED after a fall with a scalp hematoma but no skull fracture, neurologic deficit, altered alertness, abnormal behavior, coagulopathy, or persistent vomiting — run the NEXUS Head CT rule and tell me if CT is indicated."},{"title":"Low-risk young adult head trauma","prompt":"Apply the NEXUS Head CT instrument to a 34-year-old who hit their head; skull fracture: false, scalp hematoma: false, neurologic deficit: false, altered alertness: false, abnormal behavior: false, coagulopathy: false, persistent vomiting: false. Can CT be omitted?"},{"title":"Coagulopathy complicating head injury decision","prompt":"Check the NEXUS Head CT criteria for a 45-year-old patient on warfarin — skull fracture: false, scalp hematoma: false, neurologic deficit: false, altered alertness: false, abnormal behavior: false, coagulopathy: true, persistent vomiting: false. What does the rule say about CT?"}],"resultDescription":"Returns a low-risk flag (true/false) indicating whether all eight NEXUS Head CT criteria are absent (true = low-risk, CT may be omitted), along with the status of each individual criterion that triggered or cleared the rule.","failureModes":["Missing required query parameters returns a validation error","Age outside integer range 18–120 may be rejected","Non-boolean values for flag parameters cause schema validation failure","Caller-assigned findings reflect the provider's clinical assessment; the API does not validate clinical plausibility"],"whenToPreferThis":"Use this endpoint when you need to apply the Mower 2017 NEXUS Head CT rule specifically — not the Canadian CT Head Rule and not the Hoffman 2000 NEXUS C-spine rule. Prefer it when all eight criterion flags have already been clinically assessed by a provider and you need a programmatic low-risk determination for documentation, decision support, or workflow automation.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-14T18:56:26.139Z","isFirstParty":false}