Peer-review started: January 2, 2018
First decision: January 15, 2018
Revised: January 24, 2018
Accepted: February 25, 2018
Article in press: February 25, 2018
Published online: February 28, 2018
Hepatocellular carcinoma (HCC) usually develops in the setting of chronic liver disease. In the adequate clinical context, both multiphasic contrast-enhanced CT and magnetic resonance imaging are non-invasive modalities that allow accurate diagnosis and staging of HCC, although the latter demonstrates greater sensitivity and specificity. Imaging criteria for HCC diagnosis rely on hemodynamic features such as hyperenhancement in the arterial phase and washout in the portal or equilibrium phase. However, imaging performance drops considerably for small (< 20 mm) nodules because their tendency to exhibit atypical enhancement patterns. In order to improve accuracy in the diagnosis and staging of HCC, particularly in cases of atypical nodules, ancillary features, i.e., imaging characteristics that modify the likelihood of HCC, have been described and incorporated into clinical reports, especially in Liver Imaging Reporting and Data System. In this paper, ancillary imaging features will be reviewed and illustrated.
Core tip: Hepatocellular carcinoma (HCC) usually develops in the setting of chronic liver disease. Imaging criteria for HCC diagnosis rely on hemodynamic features, however, imaging diagnostic performance drops considerably for small (< 20 mm) nodules because of their tendency to exhibit atypical enhancement patterns. In order to improve accuracy in these non-typical lesions, the use of ancillary features has been incorporated into clinical reports, especially in Liver Imaging Reporting and Data System. In this paper, ancillary imaging features will be reviewed and illustrated.