Hepatocellular carcinoma and precancerous lesions: advances in imaging

Doppler and harmonic ultrasound for hepatocellular carcinoma

Ultrasound (US) is the imaging method most frequently used for the detection and diagnosis of hepatocellular carcinoma (HCC). US image quality has greatly improved in recent years, with advances in transducer, beam-former technology and sophisticated image processing. In addition, the recent availability of US contrast agents including first- and second-generation contrast agents and the remarkable advances in US technology have led to the rapid development of new imaging methods such as low and high mechanical index (MI) imaging technology for the vascular phase and parenchymal phase of the liver. In terms of contrast agent, most reported studies in Asian countries have used a very fragile, first-generation microbubble agent. Nowadays, more stable,second-generation contrast agents are developing and used in clinical application to the liver. In the future, better results can be obtained in the diagnosis of HCC, decision of treatment method and assessment of therapeutic response if more durable contrast agents are used with advanced US techniques. In this article, the principles, methods, imaging findings and potential roles of new diagnostic US techniques with contrast agents in the diagnosis of HCC are discussed.

Multidetector CT of hepatocellular carcinoma

Hepatocellular carcinoma is one of the most common causes of cancer death worldwide. Numerous surgical and nonsurgical treatment options are available for the management of patients with HCC. Successful long-term outcome is dependent on early detection of HCC, as well as accurate delineation of the number and location of tumor nodules. We present the different manifestations of hepatocellular carcinoma as depicted by multidetector-row CT with advanced image processing.

The current status of imaging diagnosis of hepatocellular carcinoma

Early detection of hepatocellular carcinoma (HCC) is important, since the most effective treatment for HCC is surgical resection or local ablation therapy when the tumor is small. Fortunately, recent advances in liver imaging techniques have facilitated the detection of small HCCs. Recent progression of noninvasive imaging technology includes various techniques of harmonic ultrasound (US) imaging with several kinds of US contrast agents, multislice helical computed tomography (CT), and rapid high-quality magnetic resonance (MR) technique with new, tissue-specific contrast agents. These techniques seem to have a strong potential to improve detection and characterization of HCC. In this review, the technique and efficacy of new imaging methods including contrast enhanced US, multislice CT, and recent MR techniques with new contrast agents for detecting and diagnosing HCC will be described.