# New Orleans Head CT Rule Calculator > New Orleans Head CT Rule Calculator 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 New Orleans (Haydel 2000) CT head rule to determine whether CT is indicated for GCS-15 minor head injury in adults based on seven clinical findings ## Facts - Endpoint: GET https://api.magentlab.com/api/calc/new_orleans_head - 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/new-orleans-head-ct-rule-calculator-d770e021 - Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_DHAz8zeW8D6cNgTihjN-6 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 new-orleans-head-ct-rule-calculator-d770e021 ``` Example prompt: My patient is a 67-year-old who had a minor head injury with GCS 15. They have a headache and vomited once, no seizure, no signs of trauma above the clavicles, not intoxicated, and no short-term memory deficit — does the New Orleans Head CT Rule indicate a CT? ## When to prefer this Use this endpoint when you need to programmatically apply the New Orleans Head CT Rule (Haydel 2000) for adult patients (18+) with GCS-15 minor head injury and need a structured, auditable computation of the seven criteria. Prefer this over manual calculation to reduce transcription errors. Do not use for pediatric patients (use PECARN), for patients with GCS below 15, or when the Canadian CT Head Rule is more appropriate. ## Known failure modes - Missing required query parameters (age, headache, vomiting, drug_or_alcohol_intoxication, short_term_memory_deficit, trauma_above_clavicles, seizure) returns a validation error - Age outside integer range 18-120 may return an error or unexpected result - Non-boolean values for boolean fields cause schema validation failure - Payment failure (x402) blocks response - Not applicable to pediatric patients, patients with GCS below 15, or non-minor head injuries ## How this service works New Orleans Head CT Rule (Haydel 2000). CT is indicated if any of seven findings: headache, vomiting, age over 60, drug or alcohol intoxication, short-term memory deficit (anterograde amnesia), physical evidence of trauma above the clavicles, or seizure. Published for GCS 15 minor head injury in adults; magent does not take GCS or examine the patient. Not a diagnosis, not the Canadian CT Head Rule, not PECARN, and not pediatric. ## Output Returns the result of the New Orleans Head CT Rule indicating whether a CT scan is indicated based on the presence or absence of the seven clinical criteria: headache, vomiting, age over 60, drug/alcohol intoxication, short-term memory deficit, trauma above clavicles, and seizure. Not a diagnosis; clinical judgment required. ## 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": [ "age", "headache", "vomiting", "drug_or_alcohol_intoxication", "short_term_memory_deficit", "trauma_above_clavicles", "seizure" ], "properties": { "age": { "type": "integer", "description": "Age in years (18-120). Age >60 is a CT indication; 60 does not. The published rule is GCS 15 minor head injury in adults; magent does not take GCS." }, "seizure": { "type": "boolean", "description": "Seizure. true or false as assigned by the caller." }, "headache": { "type": "boolean", "description": "Headache. true or false as assigned by the caller." }, "vomiting": { "type": "boolean", "description": "Vomiting. true or false as assigned by the caller." }, "trauma_above_clavicles": { "type": "boolean", "description": "Physical evidence of trauma above the clavicles. true or false as assigned by the caller." }, "short_term_memory_deficit": { "type": "boolean", "description": "Deficit in short-term memory (anterograde amnesia). true or false as assigned by the caller." }, "drug_or_alcohol_intoxication": { "type": "boolean", "description": "Drug or alcohol intoxication. true or false as assigned by the caller." } } } }, "additionalProperties": false }, "output": { "type": "object", "required": [ "type" ], "properties": { "type": { "type": "string" }, "example": { "type": "object" } } } } } ``` ## Response schema (JSON Schema) ```json { "type": "json", "example": { "path": "/api/calc/new_orleans_head", "count": 2, "items": [ { "formula": "new_orleans_head", "citation": { "id": "haydel-2000", "doi": "10.1056/NEJM200007133430204", "title": "Indications for computed tomography in patients with minor head injury", "source": "N Engl J Med. 2000;343(2):100-105", "authors": "Haydel MJ, Preston CA, Mills TJ, Luber S, Blaudeau E, DeBlieux PM" }, "criteria": [ { "met": false, "factor": "headache" }, { "met": false, "factor": "vomiting" }, { "met": false, "value": 40, "factor": "age_gt_60" }, { "met": false, "factor": "drug_or_alcohol_intoxication" }, { "met": false, "factor": "short_term_memory_deficit" }, { "met": false, "factor": "trauma_above_clavicles" }, { "met": false, "factor": "seizure" } ], "age_years": 40, "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.", "ct_indicated": false, "formula_expression": "ct indicated if any of headache, vomiting, age > 60, drug_or_alcohol_intoxication, short_term_memory_deficit, trauma_above_clavicles, or seizure" }, { "formula": "new_orleans_head", "citation": { "id": "haydel-2000", "doi": "10.1056/NEJM200007133430204", "title": "Indications for computed tomography in patients with minor head injury", "source": "N Engl J Med. 2000;343(2):100-105", "authors": "Haydel MJ, Preston CA, Mills TJ, Luber S, Blaudeau E, DeBlieux PM" }, "criteria": [ { "met": false, "factor": "headache" }, { "met": false, "factor": "vomiting" }, { "met": false, "value": 40, "factor": "age_gt_60" }, { "met": false, "factor": "drug_or_alcohol_intoxication" }, { "met": false, "factor": "short_term_memory_deficit" }, { "met": false, "factor": "trauma_above_clavicles" }, { "met": false, "factor": "seizure" } ], "age_years": 40, "disclaimer": "Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed clinician remains responsible for patient … (truncated) ``` ## More - Live health (JSON, refreshed every minute): https://www.zero.xyz/c/new-orleans-head-ct-rule-calculator-d770e021/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)