Fig. 1

Risk factor stratification algorithm. For patients without laboratory evidence of chronic HBV infection, clinical interpretations of non-tumour liver pathology specimens obtained within one year of the imaging study selected for LI-RADS assessment were used (when available) to stratify patients into RF+ and RF− groups. For patients without non-tumour liver pathology specimens, the imaging study selected for LI-RADS assessment was reviewed by an author not involved in the LI-RADS interpretation who looked for evidence of gross surface nodularity (i.e. definite cirrhosis by imaging). For patients without definite cirrhosis by imaging, an FIB-4 index calculation, a validated tool for the non-invasive prediction of advanced fibrosis (i.e. cirrhosis), was attempted [17]. Patients without the laboratory values necessary for the FIB-4 calculation within 30 days of the LI-RADS imaging study or with a FIB-4 in the 1.45–3.25 range were considered to have an indeterminate risk status. These cases were excluded. ALT = alanine transaminase; AST = aspartate transaminase; HBV = hepatitis B virus; LI-RADS = Liver Imaging Reporting and Data System; RF− = not high-risk for hepatocellular carcinoma per LI-RADS criteria; RF+ = high-risk for hepatocellular carcinoma per LI-RADS criteria; FIB-4 = Fibrosis 4 Score