# NEXUS Chest CT Decision Rule Calculator (Rodriguez 2015) > NEXUS Chest CT Decision Rule Calculator (Rodriguez 2015) is a paid API for AI agents from api.magentlab.com, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-13). Computes the NEXUS Chest CT-Major and Chest CT-All negativity criteria for blunt trauma patients to guide chest CT ordering decisions ## Facts - Endpoint: GET https://api.magentlab.com/api/calc/nexus_chest_ct - Price: $0.005/call - Payment: x402 - Status: unknown - Last checked: 2026-09-13 - Activations on Zero: 0 - Tags: x402 - Canonical page: https://www.zero.xyz/c/nexus-chest-ct-decision-rule-calculator-rodriguez-2015-2e6db4bd - Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_erhuKgXLXHlrRR5bUkvQ- 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-ct-decision-rule-calculator-rodriguez-2015-2e6db4bd ``` Example prompt: For a blunt trauma patient (age >14) with an abnormal chest X-ray but no distracting injury, no chest-wall tenderness, no sternal tenderness, no thoracic spine tenderness, no scapular tenderness, and no rapid deceleration mechanism — run the NEXUS Chest CT Rodriguez 2015 rule and tell me whether Chest CT-Major and Chest CT-All are negative. ## When to prefer this Use this endpoint when you need to apply the Rodriguez 2015 NEXUS Chest CT decision rule specifically (not the NEXUS Chest CXR instrument or Hoffman 2000 NEXUS C-spine rule) for adult blunt trauma patients (age >14). Prefer this over manual rule application to ensure consistent, reproducible scoring. Distinct from general trauma scoring APIs because it implements the specific seven-criterion NEXUS Chest CT framework with separate CT-Major and CT-All outputs. ## Known failure modes - Missing required boolean query parameters returns an error - Patient age ≤14 is outside the enrolled population and results may not be valid (not validated for pediatric patients) - Misclassification of clinical findings by caller leads to incorrect rule output — magent does not independently examine the patient or read radiographs - Rule output is not a diagnosis and should not replace clinical judgment ## How this service works NEXUS Chest CT (Rodriguez 2015). Chest CT-Major is negative only when abnormal CXR, distracting injury, chest-wall, sternal, thoracic-spine, and scapular tenderness are all absent. Chest CT-All is negative only when those six and rapid deceleration mechanism are absent. Presence of a criterion does not mandate CT. Not a diagnosis, not the NEXUS Chest CXR instrument, and not Hoffman 2000 NEXUS C-spine. Enrolled blunt trauma age >14. magent does not examine the patient or read a radiograph. ## Output Returns whether NEXUS Chest CT-Major is negative (all six criteria absent: abnormal CXR, distracting injury, chest-wall tenderness, sternal tenderness, thoracic spine tenderness, scapular tenderness) and whether Chest CT-All is negative (those six plus rapid deceleration mechanism all absent). A negative result means CT may be safely deferred per the rule; presence of any criterion means the respective instrument is not negative. Does not mandate or prohibit CT ordering. ## 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": [ "abnormal_cxr", "distracting_injury", "chest_wall_tenderness", "sternal_tenderness", "thoracic_spine_tenderness", "scapular_tenderness", "rapid_deceleration_mechanism" ], "properties": { "abnormal_cxr": { "type": "boolean", "description": "Abnormal chest radiograph as assigned by the caller (paper: any thoracic injury including clavicle fracture, or a widened mediastinum). true means the finding is present and Chest CT-Major is not negative. true or false. magent does not read a radiograph." }, "distracting_injury": { "type": "boolean", "description": "Painful, distracting injury as assigned by the caller. true means a distracting injury is present and Chest CT-Major is not negative. true or false. magent does not examine the patient." }, "sternal_tenderness": { "type": "boolean", "description": "Sternal tenderness to palpation as assigned by the caller. true means tenderness is present and Chest CT-Major is not negative. true or false. magent does not palpate the sternum." }, "scapular_tenderness": { "type": "boolean", "description": "Scapular tenderness to palpation as assigned by the caller. true means tenderness is present and Chest CT-Major is not negative. true or false. magent does not palpate the scapula." }, "chest_wall_tenderness": { "type": "boolean", "description": "Chest-wall tenderness to palpation as assigned by the caller. true means tenderness is present and Chest CT-Major is not negative. true or false. magent does not palpate the chest." }, "thoracic_spine_tenderness": { "type": "boolean", "description": "Thoracic-spine tenderness to palpation as assigned by the caller. true means tenderness is present and Chest CT-Major is not negative. true or false. magent does not palpate … (truncated) ``` ## More - Live health (JSON, refreshed every minute): https://www.zero.xyz/c/nexus-chest-ct-decision-rule-calculator-rodriguez-2015-2e6db4bd/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)