Hepatocelullar Carcinoma
About Lesson

Liver Ultrasound

US is usually enough to visualize significant lesions. There is a visualization score called   LI-RADS Vis score, based on the US technical quality categorises into A(no limitations) B (moderate limitations that may obscure small <10 mm  observations) and C (severe limitations, with marked beam attenuation with most (>50%) of either liver lobe not visualised).  

In general, lessions <1cm are too small to be characterised even by CT or MRI, and managing sampling with biopsy will be challenging. This is why it is recommended to repeat US in 3 months and another 3 months, if size is stable and normal AFP, recommend to return to bianual US. If increasing size, there is suspicion of malignancy particularly HCC.

Lesions >1cm  should be referred for contrast enhanced CT or MRI.

Imagen1
AASLD surveillance algorythm https://journals.lww.com/hep/fulltext/2023/12000/aasld_practice_guidance_on_prevention,_diagnosis,.27.aspx

Multiphasic contrast enhanced CT or MRI

They usually inject contrast wich 

1.Non-Contrast Phase (Pre-contrast Phase)

  • Images are taken before the injection of contrast material.
  • Provides a baseline for comparison and helps detect hyperdense lesions (e.g., calcifications, hemorrhagic lesions) or fatty infiltration.

2. Arterial Phase

  • Captured approximately 15–30 seconds after contrast injection.
  • Highlights blood flow from the hepatic artery.
  • Useful for identifying hypervascular lesions such as HCC, which show arterial phase hyperenhancement (APHE).

3. Portal Venous Phase

  • Acquired around 60–70 seconds after contrast injection.
  • Dominated by blood flow through the portal vein.
  • Ideal for evaluating liver parenchyma and identifying hypovascular lesions (e.g., metastases) as well as the washout of hypervascular lesions, which is a hallmark of HCC.

4. Delayed Phase (Equilibrium Phase)

  • Taken 2–5 minutes after contrast administration.
  • Contrast becomes evenly distributed in the blood vessels and extracellular spaces.
  • Useful for identifying lesions with slow contrast washout or persistent enhancement.

Hepatocellular carcinoma is highly vascular lesion, so will show hyperenhancement in the arterial phase and washout on venous or delayed phase. For example,   haemangioma should match the blood pool in each phase (same as the aorta in arterial etc).

HCC is , in contrast to most cancers, one of the few that does not need histological confirmation in Cirrhosis or high risk Hep B patients, based on the caracterisctics: 

  • Lesions >1 cm in size

  • Hypervascularity in the late arterial phase (arterial phase hyperenhancement) and

  • Washout on portal venous and/or delayed phases
  • Washout appearance Pre contrast A arterial B portal venous C and delayed phase W640
    Pre-contrast (A), arterial (B), portal venous (C), and delayed phase (D) CT images demonstrate a 48 mm lesion with arterial phase hyperenhancement (white arrow), washout appearance (black arrow), and enhancing capsule appearance (dashed arrow) Copyright DOI: 10.1007/s00261-017-1291-4 Santillan C, Fowler K, Kono Y, Chernyak V. LI-RADS major features: CT, MRI with extracellular agents, and MRI with hepatobiliary agents. Abdom Radiol (NY). 2018 Jan;43(1):75-81.

     

Based on this, a LI-RADS system was layout to assess the probability of HCC based on typical features. LI-RADS is validated in cirrhosis (Non vascular etiology) and chronic hep B with risk factors for HCC. 

Category is 1 (definitely Bening) 2(likely bening) 3 (Intermediate) 4 (likely malignant) and 5 (definitely malignant)

Original.01515467 202312000 00027.F6
American College of Radiology Committee on LI-RADS https://www.acr.org/Clinical-Resources/Reporting-and-Data-Systems/LI-RADS

 

Original.01515467 202312000 00027.F8
AASLD Practice Guidance on prevention, diagnosis, and treatment of hepatocellular carcinoma Hepatology78(6):1922-1965, December 2023.

The MRI or CT can also show size, number of lesions, its location, its relation to anatomical structures, if there is any portal vein invasions, or if there are any local or extrahepatic signs of distal involvement, as well as other important features such as presence of portal vein thrombosis, venous collaterals or ascites that can be useful for planning biopsy of potential local treatment or surgery.