On MRI, a hepatocellular carcinoma (HCC) in a cirrhotic liver shows arterial phase hyperenhancement followed by washout appearance and capsule enhancement in the portal venous/delayed phase. This pattern fulfils LI-RADS category:

• A LI-RADS 5 (definitely HCC) ✓
• B LI-RADS 3 (intermediate probability)
• C LI-RADS M (probably malignant, not HCC specific)
• D LI-RADS 4 (probably HCC)

Explanation

LI-RADS 5 (LR-5) is assigned to observations with imaging features diagnostic of HCC: a lesion ≥20 mm with arterial phase hyperenhancement (APHE) plus washout appearance, OR ≥20 mm with APHE plus capsule appearance, OR a threshold growth pattern. The combination of APHE + washout + capsule enhancement strongly predicts HCC with >95% positive predictive value in at-risk patients (cirrhosis, chronic hepatitis B), enabling diagnosis without biopsy. LR-M indicates features suggesting malignancy not specific to HCC (e.g., targetoid enhancement pattern). LR-4 requires one major feature or size criteria without meeting LR-5.

Reference: Grainger & Allison's Diagnostic Radiology, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.