CT/MRI LI-RADS
Standardized assessment of liver observations in patients at risk for hepatocellular carcinoma (HCC): cirrhosis, chronic hepatitis B, or current/prior HCC. LI-RADS is applied only to at-risk patients and not to those with cirrhosis due to congenital hepatic fibrosis or vascular disorders. Categories reflect the probability of HCC and of malignancy, using major features (arterial phase hyperenhancement, washout, enhancing capsule, size, threshold growth).
v2018·reviewed 2026-07-01
- LI-RADS applies only to patients at risk for HCC (cirrhosis, chronic HBV, or prior/current HCC). It is not used for the general population or for cirrhosis from congenital hepatic fibrosis or vascular causes.
- The full LR-3/4/5 assignment uses a 2-D diagnostic table indexed by observation size and number of additional major features (0, 1, ≥2) after establishing nonrim APHE. With nonrim APHE the size bins are <10 / 10–19 / ≥20 mm; WITHOUT APHE the bins collapse to <20 / ≥20 mm.
- Washout is a major HCC feature that raises the category — but its effect depends on APHE. WITH nonrim APHE, nonperipheral washout drives a 10–19 mm observation to LR-5 (definitely HCC). WITHOUT APHE, a <20 mm observation with only one additional major feature (even washout) stays LR-3, and needs ≥2 additional features to reach LR-4 — it can never reach LR-5 without APHE.
- Ancillary features can adjust the category by up to one step (favoring malignancy or benignity) but cannot upgrade to LR-5.
- The CT/MRI v2018 major-feature definitions were incorporated into AASLD practice guidance for HCC diagnosis in at-risk patients.
- Currency: this page summarizes the CT/MRI diagnostic algorithm (v2018, still current). The LI-RADS Treatment Response Algorithm was updated in 2024 (LR-TR v2024) — for assessing tumor response after locoregional therapy, use the current TRA rather than this diagnostic table (see the ACR LI-RADS page).
Additional major features:
Category
LR-3
Intermediate probability of malignancy. Repeat or alternative diagnostic imaging in 3–6 months.
Sources
- American College of Radiology CT/MRI LI-RADS v2018 Core. American College of Radiology, 2018.source
- Chernyak V, et al. Liver Imaging Reporting and Data System (LI-RADS) Version 2018: Imaging of Hepatocellular Carcinoma in At-Risk Patients. Radiology. 2018;289(3):816-830.
Educational reference for clinicians — not medical advice. Verify against the primary source before acting on it; guidelines change. Final decisions rest with the interpreting physician and your institution's protocols.