Early Hepatocellular Carcinoma: Diagnosing the Difficult Nodule

The incidence of hepatocellular carcinoma (HCC) is rising worldwide. Although the best chance for long-term survival is early detection, screening high-risk populations to detect HCC when it is most treatable still has only limited success. Once detected within the cirrhotic liver, many observations still defy correct characterization, due in part to a history of nonstandarized nomenclature and reporting patterns. Recently, however, an initiative by the American College of Radiology, Liver Imaging-Reporting and Data System (LI-RADS), has begun to remedy these inadequacies. Here, we review LI-RADS, and focus in particular on the difficult nodule, i.e., a radiological observation that challenges our current diagnostic ability, and review essential technical imaging features that aid in the diagnosis of early HCC.