The Liver Imaging Reporting and Data System (LI-RADS^®) is an imaging-based diagnostic system applicable in patients at high risk of hepatocellular carcinoma (HCC). In LI-RADS, each liver observation is assigned a category that reflects probability of benignity, HCC, or other malignancy. Familiarity with the LI-RADS diagnostic algorithm is necessary to appropriately implement LI-RADS in clinical practice. This review discusses steps necessary for application of the LI-RADS algorithm and provides examples illustrating each step.

Hepatocarcinogenesis is a multi-step process characterized by progressive cellular and molecular dedifferentiation of hepatocytes and culminating in the emergence of hepatocellular carcinoma (HCC). Knowledge of hepatocarcinogenesis is important because familiarity with the associated imaging features can lead to improved diagnosis of HCC at its early stages. The article reviews the alterations that accumulate leading to HCC result in abnormal imaging features, many of which are included in LI-RADS v2017 as major and ancillary features.