Liver cancer imaging: the need for accurate detection of intrahepatic disease spread

The last ten years have seen dramatic changes in the therapeutic approach to both primary (i.e., hepatocellular carcinoma: HCC) and secondary (i.e., metastatic lesions) focal liver malignancies. This has been due to the increasing proliferation of new modalities, including percutaneous ablative therapies (ethanol injection: PEI; radiofrequency: RF; laser; microwaves), angiographic therapies (segmental chemoembolization; hypoxic perfusion) and liver transplantation (OLT), in addition to a greater acceptance of pre-existing modalities (resection; systemic chemotherapy). Thus, a main aim of current medical management is to select for each patient the therapeutic modality which will provide the highest success rate, fewest risks and lowest costs for each given situation. However, in order to decide on the appropriate therapeutic choice, the accurate diagnosis of neoplastic lesions by means of one or more imaging modalities (ultrasound: US; computed tomography: CT; magnetic resonance: MR) is mandatory. This imaging work-up can be viewed as having three purposes: lesion detection, lesion characterization, intrahepatic and extrahepatic cancer staging. The present paper is concerned primarily with the imaging approach to liver lesion detection.