LI-RADS v2018 (CT and MRI)

LI-RADS applies only to patients at high risk of hepatocellular carcinoma: cirrhosis, chronic hepatitis B, or current or previous HCC. It does not apply to cirrhosis from congenital hepatic fibrosis or vascular disorders such as Budd-Chiari syndrome. Work through the steps in order.

Step 1: is the observation any of these?Definitely benign (LR-1)Probably benign (LR-2)Enhancing soft tissue in a vein (LR-TIV)Targetoid appearance or other features of non-HCC malignancy (LR-M)For example rim arterial phase hyperenhancement, peripheral washout, delayed central enhancement, targetoid restriction.None of these: go on to the diagnostic table

Step 2: sizeUnder 10 mm10 to 19 mm20 mm or more

Non-rim arterial phase hyperenhancement (APHE)PresentAbsent

Additional major featuresNon-peripheral washoutEnhancing capsuleThreshold growthSize increase of 50% or more within 6 months.

Step 3: ancillary features (optional)

Ancillary features can move the category up by one, but not up to LR-5, or down by one. If features favour both, make no adjustment.

None, or they favour both malignancy and benignityFavour malignancyFavour benignity

Enter the values above.

CT and MRI diagnostic table

Arterial phase	No APHE	No APHE	Non-rim APHE	Non-rim APHE	Non-rim APHE
Size (mm)	Under 20	20 or more	Under 10	10 to 19	20 or more
No additional major feature	LR-3	LR-3	LR-3	LR-3	LR-4
One feature	LR-3	LR-4	LR-4	LR-4 (capsule) or LR-5 (washout or threshold growth)	LR-5
Two or three features	LR-4	LR-4	LR-4	LR-5	LR-5

References

American College of Radiology. CT/MRI LI-RADS v2018 core. Reston, VA: ACR; 2018.

Chernyak V, Fowler KJ, Kamaya A, 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.