Advancement in HCC imaging: diagnosis, staging and treatment efficacy assessments

Imaging studies play a crucial role in the diagnosis and staging of hepatocellular carcinoma (HCC). Yet, assessment of tumor response is another important goal for imaging. The imaging techniques most commonly used for assessing tumor response include computed tomography and magnetic resonance imaging. Imaging modalities and imaging criteria vary according to the treatment (surgical resection and transplantation or nonsurgical treatments such as transarterial chemoembolization, radiofrequency ablation, and molecular targeted therapy). Efficacy of nonsurgical treatments for malignancy is usually evaluated with RECIST criteria. These criteria, based on tumor shrinkage, are often inappropriate in HCCs. The response criteria should take into account tumor necrosis induced by treatment. Today, tumor necrosis is estimated by a disappearance of hypervascularization on contrast-enhanced imaging. New tools such as functional imaging (perfusion imaging, diffusion-weighted MR imaging) could be of major importance. In this article, we present a summary of the most recent information on the role of imaging in assessing treatment efficacy in HCCs.