# Los Angeles classification of oesophagitis LA grading Status: LIVE Price: $0.005 USDC `GET /api/calc/la_grading` HTML: https://magentlab.com/docs/la-grading Markdown: https://magentlab.com/docs/la-grading.md Not a medical device. Not a diagnosis, dose, or listing recommendation. ## What it computes Apply Lundell 1999 Table 1 Los Angeles classification of oesophagitis and return la_grade (none, A, B, C, or D) from four caller-assigned endoscopic flags. ## When to use When an agent already has endoscopic mucosal-break flags as assigned at endoscopy (presence of a mucosal break, longest break more than 5 mm, continuity between fold tops, and at least 75% circumference) and needs the published 1999 LA grade. magent does not interpret endoscopy images. ## When not to use - Not a medical device. - Not a GERD diagnosis. magent does not diagnose gastro-oesophageal reflux disease. - The caller assigns the four endoscopic flags. magent does not interpret endoscopy images. - This tool is Lundell 1999 Table 1 Los Angeles classification only. Not Savary-Miller. Not Barrett or stricture grading (the paper records those separately). Not the 1994 proposed LA system (grade D was fully circumferential; 1999 changed D to at least 75% of circumference). - Absence of a mucosal break returns none. That is not a minimal changes grade; Lundell 1999 found those changes unreliable. ## Formula ``` la_grade is none if mucosal_break is false (no LA A-D; not minimal changes); else D if circumference_ge_75_percent (mucosal break(s) involve at least 75% of the oesophageal circumference); else C if continuous_between_folds (continuous between the tops of two or more mucosal folds but less than 75% of circumference); else B if longest_break_gt_5_mm (one or more breaks more than 5 mm that do not extend between the tops of two mucosal folds); else A (one or more breaks no longer than 5 mm that do not extend between the tops of two mucosal folds) (Lundell 1999 Table 1 Los Angeles classification) ``` ## Citation [Endoscopic assessment of oesophagitis: clinical and functional correlates and further validation of the Los Angeles classification](https://doi.org/10.1136/gut.45.2.172) Lundell LR, Dent J, Bennett JR, Blum AL, Armstrong D, Galmiche JP, Johnson F, Hongo M, Richter JE, Spechler SJ, Tytgat GN, Wallin L Gut. 1999;45(2):172-180 DOI: [10.1136/gut.45.2.172](https://doi.org/10.1136/gut.45.2.172) ## Worked example ### No mucosal break Given: `circumference_ge_75_percent=false, continuous_between_folds=false, longest_break_gt_5_mm=false, mucosal_break=false` 1. mucosal_break is false (no mucosal break as assigned) 2. longest_break_gt_5_mm, continuous_between_folds, and circumference_ge_75_percent are required and false; they do not change the result 3. la_grade is none (no LA A-D; not minimal changes) ### Mucosal breaks no longer than 5 mm, not between fold tops Given: `circumference_ge_75_percent=false, continuous_between_folds=false, longest_break_gt_5_mm=false, mucosal_break=true` 1. mucosal_break is true 2. circumference_ge_75_percent is false (not D) 3. continuous_between_folds is false (not C) 4. longest_break_gt_5_mm is false (not B) 5. la_grade is A ## Also searched as - Los Angeles classification - LA grade oesophagitis - Lundell 1999 - Los Angeles esophagitis - LA classification A B C D - mucosal break oesophagitis - reflux oesophagitis LA grade - LA 1999 oesophagitis - Los Angeles grading ## Parameters - `mucosal_break` (boolean, required): One or more mucosal breaks present, as assigned by the caller. Lundell 1999 defines a mucosal break as an area of slough or erythema with a discrete line of demarcation from adjacent more normal-looking mucosa. true or false. If false, la_grade is none (no LA A-D; not minimal changes). magent does not interpret endoscopy images. - `longest_break_gt_5_mm` (boolean, required): Longest mucosal break more than 5 mm long, as assigned by the caller (Lundell 1999 Table 1 grade B vs A). true or false. Required even when mucosal_break is false (does not change none). magent does not measure lesions. - `continuous_between_folds` (boolean, required): A mucosal break is continuous between the tops of two or more mucosal folds, as assigned by the caller (Lundell 1999 Table 1 grade C). true or false. Required even when mucosal_break is false (does not change none). magent does not interpret endoscopy images. - `circumference_ge_75_percent` (boolean, required): Mucosal break(s) involve at least 75% of the oesophageal circumference, as assigned by the caller (Lundell 1999 Table 1 grade D; the 1999 revision, not the 1994 fully circumferential proposal). true or false. Required even when mucosal_break is false (does not change none). magent does not interpret endoscopy images. ## 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. Method: `POST /api/calc/la_grading` Max items: 25 Price: unit_amount + extra_item_amount * (n - 1) (unit 5000 atomic, extra 2000 atomic) Status: 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: ```json { "items": [ { "circumference_ge_75_percent": "false", "continuous_between_folds": "false", "longest_break_gt_5_mm": "false", "mucosal_break": "false" }, { "circumference_ge_75_percent": "false", "continuous_between_folds": "false", "longest_break_gt_5_mm": "false", "mucosal_break": "false" } ] } ``` Human paywall (two-item fixture): https://api.magentlab.com/paywall/bulk/la-grading Example 200: ```json { "count": 2, "path": "/api/calc/la_grading", "items": [ { "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": "Lundell LR, Dent J, Bennett JR, Blum AL, Armstrong D, Galmiche JP, Johnson F, Hongo M, Richter JE, Spechler SJ, Tytgat GN, Wallin L", "doi": "10.1136/gut.45.2.172", "id": "lundell-1999", "pmid": "10403727", "source": "Gut. 1999;45(2):172-180", "title": "Endoscopic assessment of oesophagitis: clinical and functional correlates and further validation of the Los Angeles classification" }, "formula": "la_grading", "formula_expression": "la_grade is none if mucosal_break is false (no LA A-D; not minimal changes); else D if circumference_ge_75_percent (mucosal break(s) involve at least 75% of the oesophageal circumference); else C if continuous_between_folds (continuous between the tops of two or more mucosal folds but less than 75% of circumference); else B if longest_break_gt_5_mm (one or more breaks more than 5 mm that do not extend between the tops of two mucosal folds); else A (one or more breaks no longer than 5 mm that do not extend between the tops of two mucosal folds) (Lundell 1999 Table 1 Los Angeles classification)", "criteria": [ { "factor": "mucosal_break", "met": false }, { "factor": "longest_break_gt_5_mm", "met": false }, { "factor": "continuous_between_folds", "met": false }, { "factor": "circumference_ge_75_percent", "met": false }, { "factor": "none", "met": true }, { "factor": "A", "met": false }, { "factor": "B", "met": false }, { "factor": "C", "met": false }, { "factor": "D", "met": false } ], "la_grade": "none" }, { "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": "Lundell LR, Dent J, Bennett JR, Blum AL, Armstrong D, Galmiche JP, Johnson F, Hongo M, Richter JE, Spechler SJ, Tytgat GN, Wallin L", "doi": "10.1136/gut.45.2.172", "id": "lundell-1999", "pmid": "10403727", "source": "Gut. 1999;45(2):172-180", "title": "Endoscopic assessment of oesophagitis: clinical and functional correlates and further validation of the Los Angeles classification" }, "formula": "la_grading", "formula_expression": "la_grade is none if mucosal_break is false (no LA A-D; not minimal changes); else D if circumference_ge_75_percent (mucosal break(s) involve at least 75% of the oesophageal circumference); else C if continuous_between_folds (continuous between the tops of two or more mucosal folds but less than 75% of circumference); else B if longest_break_gt_5_mm (one or more breaks more than 5 mm that do not extend between the tops of two mucosal folds); else A (one or more breaks no longer than 5 mm that do not extend between the tops of two mucosal folds) (Lundell 1999 Table 1 Los Angeles classification)", "criteria": [ { "factor": "mucosal_break", "met": false }, { "factor": "longest_break_gt_5_mm", "met": false }, { "factor": "continuous_between_folds", "met": false }, { "factor": "circumference_ge_75_percent", "met": false }, { "factor": "none", "met": true }, { "factor": "A", "met": false }, { "factor": "B", "met": false }, { "factor": "C", "met": false }, { "factor": "D", "met": false } ], "la_grade": "none" } ] } ``` ## Response fields - `formula` (string): la_grading - `formula_expression` (string): Published Lundell 1999 Table 1 Los Angeles classification rule - `la_grade` (string): none, A, B, C, or D. none if no mucosal break; D if break(s) involve at least 75% of circumference; C if continuous between fold tops but less than 75%; B if longest break more than 5 mm and not between fold tops; A if break(s) no longer than 5 mm and not between fold tops. Not a GERD diagnosis. - `criteria` (array): Per-factor rows with factor and met for the four caller-assigned flags and exclusive grades none, A, B, C, D; exactly one grade row is met - `citation` (object): Lundell 1999 Gut citation - `disclaimer` (string): Not-a-device notice ## Example JSON Frozen fixture. Not a live lookup. ```json { "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": "Lundell LR, Dent J, Bennett JR, Blum AL, Armstrong D, Galmiche JP, Johnson F, Hongo M, Richter JE, Spechler SJ, Tytgat GN, Wallin L", "doi": "10.1136/gut.45.2.172", "id": "lundell-1999", "pmid": "10403727", "source": "Gut. 1999;45(2):172-180", "title": "Endoscopic assessment of oesophagitis: clinical and functional correlates and further validation of the Los Angeles classification" }, "formula": "la_grading", "formula_expression": "la_grade is none if mucosal_break is false (no LA A-D; not minimal changes); else D if circumference_ge_75_percent (mucosal break(s) involve at least 75% of the oesophageal circumference); else C if continuous_between_folds (continuous between the tops of two or more mucosal folds but less than 75% of circumference); else B if longest_break_gt_5_mm (one or more breaks more than 5 mm that do not extend between the tops of two mucosal folds); else A (one or more breaks no longer than 5 mm that do not extend between the tops of two mucosal folds) (Lundell 1999 Table 1 Los Angeles classification)", "criteria": [ { "factor": "mucosal_break", "met": false }, { "factor": "longest_break_gt_5_mm", "met": false }, { "factor": "continuous_between_folds", "met": false }, { "factor": "circumference_ge_75_percent", "met": false }, { "factor": "none", "met": true }, { "factor": "A", "met": false }, { "factor": "B", "met": false }, { "factor": "C", "met": false }, { "factor": "D", "met": false } ], "la_grade": "none" } ``` ## Errors - HTTP 400 `invalid_flag`: boolean clinical flags must be true or false Returned before settlement; you are not charged. - HTTP 400 `invalid_items`: POST body must be a JSON object with only an items array Returned before settlement; you are not charged. - HTTP 400 `invalid_item_count`: items must be an array of 1 to 25 objects Returned before settlement; you are not charged. - HTTP 400 `invalid_item`: each items entry must be a JSON object Returned before settlement; you are not charged. Shared HTTP 402 and 503: https://magentlab.com/docs/payments ## Related tools - [Forrest](https://magentlab.com/docs/forrest) — Return the Forrest 1974 endoscopic lesion class (ia, ib, iia, iib, iic, or iii) and published description from a caller-assigned token. - [Rome IV FD](https://magentlab.com/docs/rome-iv-fd) — Apply the Stanghellini 2016 Rome IV B1 functional dyspepsia criteria and return whether PDS (B1a), EPS (B1b), and the published FD box hold (rome_iv_fd). - [Travis criteria](https://magentlab.com/docs/travis) — Apply the Travis 1996 day-3 of intravenous corticosteroids rule for severe ulcerative colitis and return travis_high from stools_per_day and crp_mg_l. ## 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. - GET the tool with Accept: application/json (do not send Accept: text/html unless you want the human paywall). - HTTP 402 means you have not paid. Decode the base64 PAYMENT-REQUIRED header. HTTP 503 is not a new quote. - Sign accepts[0] (exact, EIP-3009) with validBefore = now + maxTimeoutSeconds (600 seconds), or accepts[1] (batch-settlement deposit/voucher) on product GET. Ping and POST {items} stay exact. Magent retries transient facilitator 429/5xx before answering. - Retry the same URL with PAYMENT-SIGNATURE (base64 JSON of accepted and payload). Magent attaches canonical extensions.bazaar on CDP verify/settle; echoing 402 bazaar is optional. - Success is HTTP 200 JSON plus PAYMENT-RESPONSE. exact settles before the tool. batch-settlement verifies (and deposit-settles) before the tool and commits the charge after HTTP 2xx. HTTP 503: retry the same PAYMENT-SIGNATURE. Mint a new exact nonce only after a new HTTP 402. - offered `exact` on eip155:8453: Fixed-price USDC on Base. The buyer authorizes the advertised amount (EIP-3009). magent settles before the tool runs (paymentFlow upfront). extra.assetTransferMethod=eip3009 extra.paymentFlow=upfront. - offered `batch-settlement` on eip155:8453: Payment-channel vouchers claimed later in batches. Exact stays accepts[0]. Same-path POST {items} is still exact. extra.assetTransferMethod=eip3009 extra.paymentFlow=authorization. - not offered `upto`: Not offered. Usage-based: buyer authorizes a ceiling, seller settles the actual amount after work. Reserved for a future metered tool. Not for current calculators or code search. Same-path POST {items} is still scheme exact: one EIP-3009 authorization for GET unit plus $0.002 per extra item. That is not x402 batch-settlement (payment channels / vouchers). Shared HTTP 402 and 503 table: https://magentlab.com/docs/payments Stdio MCP (one process per host): https://magentlab.com/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. HTTP 402 never includes the tool JSON. - 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.