# NEXUS Chest Radiography Decision Instrument (Rodriguez 2011) > NEXUS Chest Radiography Decision Instrument (Rodriguez 2011) 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 7-criterion NEXUS Chest rule to determine whether chest radiography is indicated in blunt trauma patients by checking for the presence of any of seven caller-assigned clinical findings. ## Facts - Endpoint: GET https://api.magentlab.com/api/calc/nexus_chest - Price: $0.005/call - Payment: x402 - Status: unknown - Last checked: 2026-09-15 - Activations on Zero: 0 - Tags: x402 - Canonical page: https://www.zero.xyz/c/nexus-chest-radiography-decision-instrument-rodriguez-2011-47245254 - Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Sk5QP3CPB3FJNIDP_j-M1 Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently. ## How to call it through Zero Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`): ```sh zero fetch --capability nexus-chest-radiography-decision-instrument-rodriguez-2011-47245254 ``` Example prompt: Run the NEXUS Chest rule for a blunt trauma patient: chest pain is present, no distracting injury, no chest-wall tenderness, not intoxicated, age is not over 60, the mechanism was a 45 mph motor vehicle crash so rapid deceleration is true, and mental status is normal — is chest radiography indicated? ## When to prefer this Use this endpoint when you need to apply the Rodriguez 2011 NEXUS Chest plain radiography rule specifically — not the NEXUS C-spine rule, not a Chest CT decision rule, and not any other chest imaging instrument. It is appropriate for blunt trauma patients over 14 years old when a caller has already assessed and assigned the seven clinical criteria. Prefer this over manual lookup when automating trauma triage workflows or building clinical decision support agents that need a programmatic, auditable application of the NEXUS Chest instrument. ## Known failure modes - Missing any of the seven required boolean query parameters returns a validation error - Supplying non-boolean values for the flags causes a schema rejection - Attempting to use this instrument for pediatric patients under 14 years old is outside the derivation population and may produce a warning or unsupported response - Confusing this endpoint with NEXUS C-spine (Hoffman 2000) or NEXUS Chest CT instruments returns valid but contextually incorrect results for those use cases - Network or payment authorization failure returns an HTTP 402 or connectivity error ## How this service works NEXUS Chest (Rodriguez 2011). Chest radiography is not indicated by this instrument only when all seven caller-assigned findings are absent: chest pain, distracting injury, chest-wall tenderness, intoxication, age >60, rapid deceleration, and altered mental status. Any one present means chest x-ray is indicated. Not a diagnosis, not Hoffman 2000 NEXUS C-spine, and not a NEXUS Chest CT instrument. Derivation enrolled blunt trauma age >14. magent does not examine the patient. ## Output Returns whether chest radiography is indicated or not indicated based on the NEXUS Chest rule: if any of the seven criteria flags is true the instrument indicates chest x-ray is required; only if all seven are false is the patient considered low-risk and chest x-ray not indicated. Response reflects the Rodriguez 2011 derivation logic only. ## Request schema (JSON Schema) ```json { "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": [ "chest_pain", "distracting_injury", "chest_wall_tenderness", "intoxication", "age_gt_60", "rapid_deceleration", "altered_mental_status" ], "properties": { "age_gt_60": { "type": "boolean", "description": "Age greater than 60 years as assigned by the caller (a NEXUS Chest criterion, not a numeric age input). true means age >60 and the low-risk criterion fails. true or false. magent does not take numeric age." }, "chest_pain": { "type": "boolean", "description": "Chest pain. true means chest pain is present and the low-risk criterion fails. true or false as assigned by the caller. magent does not examine the patient." }, "intoxication": { "type": "boolean", "description": "Intoxication. true means intoxicated and the low-risk criterion fails. true or false as assigned by the caller." }, "distracting_injury": { "type": "boolean", "description": "Painful, distracting injury. true means a distracting injury is present and the low-risk criterion fails. true or false as assigned by the caller." }, "rapid_deceleration": { "type": "boolean", "description": "Rapid deceleration mechanism (paper: fall from >20 feet or motor vehicle crash >40 mph) as assigned by the caller. true means the mechanism is present and the low-risk criterion fails. true or false. magent does not classify mechanism." }, "altered_mental_status": { "type": "boolean", "description": "Altered alertness or mental status. true means altered mental status is present and the low-risk criterion fails. true or false as assigned by the caller. magent does not examine the patient." }, "chest_wall_tenderness": { "type": "boolean", "description": "Tenderness to chest-wall palpation. true means tenderness is present and … (truncated) ``` ## Response schema (JSON Schema) ```json { "type": "json", "example": { "path": "/api/calc/nexus_chest", "count": 2, "items": [ { "formula": "nexus_chest", "citation": { "id": "rodriguez-2011", "doi": "10.1097/TA.0b013e3181f2ac9d", "pmid": "21045745", "title": "Derivation of a decision instrument for selective chest radiography in blunt trauma", "source": "J Trauma. 2011;71(3):549-553", "authors": "Rodriguez RM, Hendey GW, Mower W, et al." }, "criteria": [ { "met": true, "factor": "no_chest_pain" }, { "met": true, "factor": "no_distracting_injury" }, { "met": true, "factor": "no_chest_wall_tenderness" }, { "met": true, "factor": "no_intoxication" }, { "met": true, "factor": "no_age_gt_60" }, { "met": true, "factor": "no_rapid_deceleration" }, { "met": true, "factor": "no_altered_mental_status" } ], "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.", "formula_expression": "NEXUS Chest low-risk iff no chest pain and no distracting injury and no chest-wall tenderness and no intoxication and age not >60 and no rapid deceleration and no altered mental status", "chest_xray_indicated": false, "nexus_chest_low_risk": true }, { "formula": "nexus_chest", "citation": { "id": "rodriguez-2011", "doi": "10.1097/TA.0b013e3181f2ac9d", "pmid": "21045745", "title": "Derivation of a decision instrument for selective chest radiography in blunt trauma", "source": "J Trauma. 2011;71(3):549-553", "authors": "Rodriguez RM, Hendey GW, Mower W, et al." }, "criteria": [ { "met": true, "factor": "no_chest_pain" }, { "met": true, "factor": "no_distracting_injury" }, { "met": true, "factor": "no_chest_wall_tenderness" }, { "met": true, "factor": "no_intoxication" }, { "met": true, "factor": "no_age_gt_60" }, { "met": true, "factor": "no_rapid_deceleration" }, { "met": true, "factor": "no_altered_mental_status" } ], "disclaimer": "Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed c … (truncated) ``` ## More - Live health (JSON, refreshed every minute): https://www.zero.xyz/c/nexus-chest-radiography-decision-instrument-rodriguez-2011-47245254/health.json - [Zero catalog index](https://www.zero.xyz/llms.txt) - [Other services from api.magentlab.com](https://www.zero.xyz/host/api.magentlab.com/llms.txt)