Modified Fisher SAH CT grade (Frontera 2006)

Modified Fisher

Return the Frontera 2006 modified Fisher CT grade 0-4 from a caller-assigned grade, with the published grade description.

LIVE $0.005 USDC GET /api/calc/modified_fisher

Markdown: /docs/modified-fisher.md · Canonical: https://magentlab.com/docs/modified-fisher

Not a medical device. Not a diagnosis, dose, or listing recommendation.

What it computes

Return the Frontera 2006 modified Fisher CT grade 0-4 from a caller-assigned grade, with the published grade description.

When to use

When an agent needs the modified Fisher (Frontera 2006) CT grades 0-4 and must not invent Fisher 1980 original groups, a millimetre thin/thick cutoff, or a linear vasospasm-risk percentage.

When not to use

Not a medical device and not a diagnosis. magent does not read the CT.
This is Frontera 2006 modified Fisher grades 0-4. It is not Fisher 1980 original groups 1-4 (those have no grade 0).
Frontera 2006 did not apply explicit criteria for thin versus thick. magent does not invent a millimetre cutoff. Crude odds of symptomatic vasospasm versus grades 0-1 were OR 1.6 (grade 2), OR 1.6 (grade 3), and OR 2.2 (grade 4). magent returns grade and description only.

Formula

Frontera 2006 modified Fisher CT grade 0-4 as assigned by the caller

Citation

Title: Prediction of symptomatic vasospasm after subarachnoid hemorrhage: the modified fisher scale
Authors: Frontera JA, Claassen J, Schmidt JM, et al.
Source: Neurosurgery. 2006;59(1):21-27
DOI: 10.1227/01.NEU.0000218821.34014.1B

Worked example

Grade 1 thin SAH, no IVH

Given: grade=1

grade 1 → focal or diffuse, thin SAH, no IVH

Also searched as

modified Fisher
modified Fisher scale
modified Fisher grade
Frontera 2006
modified Fisher CT
SAH modified Fisher
mFS
Frontera modified Fisher
modified Fisher IVH

Try

Opens the live endpoint. Unpaid browser requests show the paywall; agents should send Accept: application/json.

/api/calc/modified_fisher?grade=1

Full URL: https://api.magentlab.com/api/calc/modified_fisher?grade=1

Call

Expect HTTP 402 until you retry with PAYMENT-SIGNATURE. Incomplete query params return HTTP 400 before any quote or charge.

curl -i -H "Accept: application/json" "https://api.magentlab.com/api/calc/modified_fisher?grade=1"

Parameters

Name	Type	Required	Description
`grade`	integer	required	Frontera 2006 modified Fisher CT grade 0-4 as assigned by the caller from CT (0 no SAH or IVH; 1 focal or diffuse thin SAH, no IVH; 2 focal or diffuse thin SAH with IVH; 3 thick SAH, no IVH; 4 thick SAH with IVH). magent does not read the CT. Not Fisher 1980 original groups 1-4.

Bulk (POST)

POST the same path with a JSON items array. The first item is the GET unit; each additional item is $0.002. Invalid items return HTTP 400 before settlement.

POST /api/calc/modified_fisher Max 25 unit_amount + extra_item_amount * (n - 1) extra $0.002 PREVIEW

1 to 25 items. Each item uses the same keys as the GET query parameters.
POST of 1 item costs the same as GET. Lists longer than 25: chunk into multiple POSTs. Extra items still execute; do not pad dummy rows.
The first invalid item fails the whole request (index in the 400 JSON). You are not charged.
HTTP 200 is {count, path, items}. Each items[i] is the GET 200 body for that row.
Catalog misses (empty matches, found=false) stay paid 200s inside that slot.
x402 resource URL is this path plus n and body_sha256. Browsers that prefer text/html get the same paywall as GET; Pay retries POST with the same items.

Example request (fixture)

{
  "items": [
    {
      "grade": "1"
    },
    {
      "grade": "1"
    }
  ]
}

Open bulk paywall →

Opens a two-item fixture on the API host. Unpaid browsers get the same MetaMask paywall as GET; Pay retries POST with those items.

Example 200 (fixture)

{
  "count": 2,
  "path": "/api/calc/modified_fisher",
  "items": [
    {
      "description": "Focal or diffuse, thin SAH, no IVH",
      "components": [
        {
          "factor": "grade",
          "points": 1,
          "present": true
        }
      ],
      "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.",
      "citation": {
        "authors": "Frontera JA, Claassen J, Schmidt JM, et al.",
        "doi": "10.1227/01.NEU.0000218821.34014.1B",
        "id": "frontera-2006",
        "pmid": "16823296",
        "source": "Neurosurgery. 2006;59(1):21-27",
        "title": "Prediction of symptomatic vasospasm after subarachnoid hemorrhage: the modified fisher scale"
      },
      "formula": "modified_fisher",
      "formula_expression": "Frontera 2006 modified Fisher CT grade 0-4 as assigned by the caller",
      "max_score": 4,
      "score": 1,
      "grade": 1
    },
    {
      "description": "Focal or diffuse, thin SAH, no IVH",
      "components": [
        {
          "factor": "grade",
          "points": 1,
          "present": true
        }
      ],
      "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.",
      "citation": {
        "authors": "Frontera JA, Claassen J, Schmidt JM, et al.",
        "doi": "10.1227/01.NEU.0000218821.34014.1B",
        "id": "frontera-2006",
        "pmid": "16823296",
        "source": "Neurosurgery. 2006;59(1):21-27",
        "title": "Prediction of symptomatic vasospasm after subarachnoid hemorrhage: the modified fisher scale"
      },
      "formula": "modified_fisher",
      "formula_expression": "Frontera 2006 modified Fisher CT grade 0-4 as assigned by the caller",
      "max_score": 4,
      "score": 1,
      "grade": 1
    }
  ]
}

Response

Field	Type	Description
`formula`	string	modified_fisher
`formula_expression`	string	Published grade rule
`grade`	integer	Caller-assigned Frontera 2006 modified Fisher grade 0-4
`score`	integer	Same as grade
`max_score`	integer	4
`description`	string	Frontera 2006 wording for that grade
`components`	array	Assigned-grade component
`citation`	object	Frontera 2006
`disclaimer`	string	Not a medical device

Example JSON

Machine form of the same example. Frozen fixture. Not a live lookup.

{
  "description": "Focal or diffuse, thin SAH, no IVH",
  "components": [
    {
      "factor": "grade",
      "points": 1,
      "present": true
    }
  ],
  "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.",
  "citation": {
    "authors": "Frontera JA, Claassen J, Schmidt JM, et al.",
    "doi": "10.1227/01.NEU.0000218821.34014.1B",
    "id": "frontera-2006",
    "pmid": "16823296",
    "source": "Neurosurgery. 2006;59(1):21-27",
    "title": "Prediction of symptomatic vasospasm after subarachnoid hemorrhage: the modified fisher scale"
  },
  "formula": "modified_fisher",
  "formula_expression": "Frontera 2006 modified Fisher CT grade 0-4 as assigned by the caller",
  "max_score": 4,
  "score": 1,
  "grade": 1
}

Client errors (HTTP 400)

Invalid params return 400 without charge. Shared HTTP 402 and 503 meanings: Payments.

HTTP	Code	When
400	`invalid_modified_fisher_grade`	grade must be an integer from 0 to 4 (Frontera 2006 modified Fisher). Returned before settlement; you are not charged.
400	`invalid_items`	POST body must be a JSON object with only an items array Returned before settlement; you are not charged.
400	`invalid_item_count`	items must be an array of 1 to 25 objects Returned before settlement; you are not charged.
400	`invalid_item`	each items entry must be a JSON object Returned before settlement; you are not charged.

Related tools

Fisher — Return the Fisher 1980 original CT group 1-4 from a caller-assigned grade, with the published group description.
Hunt-Hess — Return the Hunt and Hess 1968 subarachnoid-hemorrhage surgical-risk grade from a caller-assigned grade 1-5, applying the paper's next-less-favorable bump when serious systemic disease is present.
ICH Score — Compute the Hemphill 2001 ICH Score from caller-assigned GCS, age, infratentorial origin, ICH volume, and IVH.

Payment

Unpaid requests return HTTP 402 even if query parameters or POST items are missing or invalid, so CDP and agents can index the path. After a PAYMENT-SIGNATURE, invalid params return HTTP 400 JSON before settlement. magent does not charge. Fix the params, then request a new 402 quote for that complete URL. Catalog misses (empty matches, found=false) are valid paid 200s. Unpaid valid requests return HTTP 402 with a base64 PAYMENT-REQUIRED header. HTTP 503 is not a new quote: retry the same PAYMENT-SIGNATURE. Full handshake and shared payment errors: Payments. Stdio MCP: /docs/mcp.

Guarantees

HTTP 402 is unpaid, including a missing query. After PAYMENT-SIGNATURE, invalid parameters return HTTP 400 before settlement. You are not charged.
exact: settlement finishes before the tool (paymentFlow upfront). batch-settlement: verify/deposit before the tool; chargedCumulativeAmount commits after HTTP 2xx. Uncertain or failed settlement fails closed (HTTP 503). Retry the same PAYMENT-SIGNATURE.
HTTP 402 is unpaid only. Do not sign a second authorization because of a 503.
Execution is timeout-bounded and concurrency-capped.
Calculator inputs are stored encrypted for allowlisted operators (Magent Console). They are not in public logs, SSH lookups, catalog, or rollups. Request logs store path without query.