The purpose of this study is to compare sensitivity for hepatocellular carcinoma (HCC) of bi-annual ultrasonography and low dose computed tomography (LDCT) in patients at high risk of HCC.

Patients at high risk of HCC are recommended to undergo biannual surveillance using ultrasound. In this study, LDCT is performed in addition to biannual ultrasound surveillance in eligible patients to compare their sensitivity for HCC. Standard of reference would be follow-up imaging and/or gadoxetic acid-enhanced liver MRI.

Inclusion Criteria:

All conditions have to be satisfied to be enrolled.

• > 20 years
• high risk group of HCC according to AASLD guideline
• risk index > = 2.33
• currently on regular biannual surveillance using ultrasonography
• sign informed consent

Exclusion Criteria:

Patients with any of following condition cannot be enrolled.

• previously diagnosed with HCC
• any contraindication of contrast enhanced CT including allergic reaction to iodine
• history of other malignancy

Patients at high risk of HCC AND High Risk Index (>=2.33)

Risk Index = 1.65 (if the prothrombin activity is <=75%) + 1.41 (if the age is 50 years or older) + 0.92 (if the platelet count is <=100x10(3)/mm3) + 0.74 (if the presence of anti-hepatitis C virus [HCV] or hepatitis B surface antigen [HBsAg] is positive).