LI-RADS Category Estimator
Use this quick tool to estimate a LI-RADS category from common major imaging features. This is intended for study and workflow support only.
Model scope: simplified CT/MRI-style major feature logic. LR-M, treatment response, and full ancillary feature handling are not included.
What is LI-RADS?
LI-RADS (Liver Imaging Reporting and Data System) is a standardized framework used to describe liver observations in patients at risk for hepatocellular carcinoma (HCC). It helps radiologists communicate clearly and consistently with hepatology, oncology, surgery, and transplant teams.
Instead of vague wording, LI-RADS assigns a category (for example, LR-3 or LR-5) based on imaging features such as arterial enhancement, washout, capsule, growth, and lesion size. Consistent reporting can improve follow-up planning and multidisciplinary care discussions.
How this LI-RADS calculator works
This page uses a practical decision tree built around major features commonly used in LI-RADS classification:
- Observation size in millimeters
- Non-rim arterial phase hyperenhancement (APHE)
- Non-peripheral washout
- Enhancing capsule
- Threshold growth
- Tumor in vein (TIV)
- Definitely benign appearance
The output includes an estimated category and a short interpretation. In real practice, complete LI-RADS assessment may require additional context such as study quality, risk status, ancillary features, and exclusion criteria.
Quick category reference
LR-1: Definitely benign
Lesion appearance is clearly benign. Typical examples include simple cysts or classic hemangiomas when features are definitive.
LR-2: Probably benign
Very low probability of HCC. Usually followed with routine surveillance depending on clinical context.
LR-3: Intermediate probability
Indeterminate findings. These lesions often require short-interval imaging follow-up or further workup.
LR-4: Probably HCC
High probability of HCC, but not meeting strict LR-5 criteria. Often prompts multidisciplinary discussion and management planning.
LR-5: Definitely HCC (imaging criteria)
Imaging features are highly specific for HCC in the appropriate at-risk population.
LR-TIV: Tumor in vein
Presence of definite enhancing soft tissue in vein indicating macrovascular invasion, which strongly impacts staging and treatment options.
Best practices when using an online LI-RADS calculator
- Confirm that the patient is in an appropriate LI-RADS risk population.
- Use high-quality multiphasic CT or MRI protocol data.
- Classify each observation separately if multiple lesions are present.
- Document key major features explicitly in your report.
- Cross-check with the current official LI-RADS guidance.
Limitations to keep in mind
No simplified calculator can replace expert image interpretation. Real-world categorization may involve subtle pattern recognition and integration of clinical context, prior imaging, and ancillary findings. This tool is most useful as a teaching aid and a quick consistency check, not as a stand-alone diagnostic decision maker.