Saved Results

No results saved yet.

Enter a patient name and hit Save on a result.

Clinical calculator summary

ACR CT/MRI LI-RADS v2018 diagnostic algorithm

A source-table categorization system for liver observations in an eligible high-risk population.

Evidence-based context for fast calculator use

Purpose:
Reproduce the ACR diagnostic category pathway while preserving feature identity, raw-size boundaries, terminal precedence, and ancillary limits.
Population:
Adults meeting ACR high-risk criteria with an eligible CT/MRI examination and an untreated observation without pathologic proof.
Factors:
Applicability and exam adequacy, Definite TIV and pretable category, APHE and raw size, Washout, capsule, and threshold growth, Optional ancillary features
Reference:
American College of Radiology. CT/MRI LI-RADS v2018 Core; Chernyak et al. Radiology. 2018. DOI 10.1148/radiol.2018181494.
HomeACR CT/MRI LI-RADS® v2018 Diagnostic Algorithm
Pin your most used calculators here by clicking the star in the dropdown.

ACR CT/MRI LI-RADS® v2018 Diagnostic Algorithm

Definite TIV takes precedence as LR-TIV; uncertainty is treated as absent by this implementation.

Select LR-1, LR-2, or LR-M only when that pretable identity has been established; otherwise use the diagnostic matrix.

mm

Enter a positive raw unrounded size; 10 mm and 20 mm boundaries are applied exactly.

Clinical Context & Background

This calculator implements the current ACR CT/MRI LI-RADS v2018 diagnostic algorithm. The ACR v2024 releases address treatment response and do not replace this diagnostic version.
Applicability, exam adequacy, observation status, LR-NC, LR-TIV, LR-1, LR-2, LR-M, rim APHE, raw size, each additional major feature, and optional ancillary adjustment are handled explicitly. Uncertain imaging features are treated as absent, and no final radiologist reasonableness assessment or management decision is automated.
Formula Logic
ACR CT/MRI LI-RADS v2018 diagnostic precedence and source matrix, followed by optional ancillary adjustment; ancillary features cannot upgrade to LR-5.

Reference Data

CategorySource roleAutomated boundary
LR-NCNoncategorizableImage omission/degradation prevents meaningful categorization
LR-1Definitely benign terminologyPretable category, then optional ancillary adjustment
LR-2Probably benign terminologyPretable category, then optional ancillary adjustment
LR-3Intermediate probabilityDiagnostic matrix or ancillary adjustment
LR-4Probably HCCDiagnostic matrix; maximum ancillary upgrade
LR-5Definitely HCC terminologyDiagnostic matrix only; never an ancillary upgrade
LR-MMalignant, not HCC-specificPretable LR-M features or rim APHE
LR-TIVDefinite tumor in veinDefinite TIV precedence

Clinical Workflow

Use, Interpret, And Continue The Patient Pathway

Expand for workflow guidance, limitations, examples, and related next steps.

When To Use

  • For diagnostic multiphase CT or MRI in an adult who meets ACR high-risk criteria.
  • For an untreated liver observation without pathologic proof.

How To Interpret

  • The output is an ACR imaging category, not a pathology result or individualized probability.
  • LR-NC, LR-M, and LR-TIV are terminal automated pathways and do not receive ancillary adjustment.
  • Uncertain APHE, washout, capsule, threshold growth, or TIV is treated as absent for automated categorization.

What To Do Next

  • Complete the ACR-required final reasonableness assessment and integrate the category with the full report and multidisciplinary clinical context.

Limitations

  • Not applicable to children, patients outside the ACR high-risk population, treated observations, path-proven observations, or ineligible examination techniques.
  • Does not perform treatment-response assessment; the ACR 2024 treatment-response releases are separate.
  • Does not automate management, biopsy, transplantation, or treatment decisions.

Validated Population

ACR-defined adult high-risk population for CT/MRI diagnostic LI-RADS v2018.

Liver cancer calculator hubReview liver imaging, function, staging, and transplant-context tools.ALBI liver-function gradeAssess a separate laboratory-based liver-function question.BCLC HCC stagingUse a separate HCC staging framework after diagnostic integration.HKLC HCC stagingUse the original nine-category 2014 HCC staging framework.

Calculation verification history

Verified

  1. : Production browser revalidation

    • Three source-backed LI-RADS v2018 cases passed through visible production controls across the non-adult applicability gate, LR-TIV precedence, and LR-5.
    • The former contradictory not-applicable trace was absent; no unexpected N/A, literal undefined value, stale control, or browser-console error was observed.
    Download latest production check (Excel)

    Case-level evidence is retained in validation/browser-revalidation/lirads-hcc-2026-08-03.json.

  2. : Local browser remediation

    • Intentional Not applicable results now use a LI-RADS-specific `category not assigned` receipt instead of the contradictory generic missing-or-invalid-input trace.
    • Ten source-backed cases passed through visible local browser controls across 11 submissions, covering all eight categories, exact 10 mm and 20 mm boundaries, applicability/exam/TIV/rim precedence, ancillary upgrade, and reset/repeat behavior.
    • The existing calculator-specific audit passed 352/352. Production status remains open until this commit is deployed and the public route is revalidated.

    Local case-level remediation evidence is retained in validation/browser-production/lirads-hcc.local-remediation.json.

  3. : Production browser validation

    • Ten source-backed cases were exercised on the public production route through visible browser controls; 10/10 case records passed their expected-versus-observed assertions across 11 visible submissions.
    • Overall browser status: failed-ui-console. medium: A correctly withheld non-adult result is labeled Not applicable but its visible trace simultaneously says Required input is missing or invalid. | medium: Production emitted minified React error #418 during route loads and interactions.
    • Case-level inputs, expected and observed results, reset/repeat behavior, failure reproductions, and console evidence are retained in the production-browser evidence record.

    Case-level production evidence is retained in validation/browser-production/lirads-hcc.json.

  4. : Full validation test

    • 352/352 source-matrix, boundary, applicability, terminal-precedence, ancillary, malformed-input, UI/reset, trace, registry, report, and mirror assertions passed with zero category mismatch.
    • This is source-to-code implementation verification, not independent clinical validation, final radiologist assessment, or management advice.

  5. : Correction

    • Reconciled the permanent lirads-hcc route to the current ACR CT/MRI LI-RADS v2018 diagnostic algorithm and separated the v2024 treatment-response releases.
    • Restored explicit applicability, exam adequacy, untreated/no-pathology status, LR-NC/LR-1/LR-2/LR-M/LR-TIV precedence, rim APHE, raw size, and separate washout/capsule/threshold-growth identities.
    • Removed defaults, coercive and malformed-value acceptance, 16 source-distinct state errors, automated management directives, and unsupported certainty wording; added strict ancillary limits and an ordered decision trace.

    Included in the current validation report.

Verification confirms the calculator implementation against the cited model; it is not independent clinical validation, regulatory approval, or medical advice.

Found a possible issue? Report it to improve this calculator

Share This Calculator

Share:

Related Tools

ALBI ScoreBCLC 2026 Hepatocellular Carcinoma StageOriginal Hong Kong Liver Cancer Staging System (HKLC-9, 2014)

Frequently Asked Questions

Who is eligible for CT/MRI LI-RADS v2018?

Use the diagnostic algorithm only for adults who meet the ACR high-risk population criteria and have an eligible multiphase CT or MRI examination of an untreated observation without pathologic proof.

Is this the LI-RADS v2024 treatment-response algorithm?

No. This page implements the CT/MRI LI-RADS v2018 diagnostic algorithm. The ACR v2024 releases address separate treatment-response workflows.

Can this LI-RADS calculator be used for ultrasound?

No. This route is for diagnostic CT/MRI LI-RADS. Ultrasound surveillance and O-RADS adnexal ultrasound are separate systems with different populations and purposes.

What does a LI-RADS category represent?

It is an ACR imaging category for an eligible observation, not a pathology result or an individualized probability. LR-M and LR-TIV also require their source-specific interpretation.

Can ancillary features upgrade an observation to LR-5?

No. In CT/MRI LI-RADS v2018, optional ancillary adjustment cannot upgrade an observation to LR-5.

Does the LI-RADS result determine biopsy or treatment?

No. The radiologist must complete the required reasonableness assessment and integrate the category with the full report, current guidance, and multidisciplinary clinical context.

Evidence-based oncology decision support. Verify with clinical guidelines.