Review
Copyright ©2009 Baishideng Publishing Group Co., Limited. All rights reserved.
World J Radiol. Dec 31, 2009; 1(1): 86-91
Published online Dec 31, 2009. doi: 10.4329/wjr.v1.i1.86
Contrast-enhanced harmonic ultrasound imaging in ablation therapy for primary hepatocellular carcinoma
Yasunori Minami, Masatoshi Kudo
Yasunori Minami, Masatoshi Kudo, Division of Gastroenterology and Hepatology, Department of Internal Medicine, Kinki University School of Medicine, 377-2 Ohno-Higashi Osaka-Sayama, 589-8511, Japan
Author contributions: Minami Y and Kudo M both contributed equally to collecting data and writing this manuscript.
Correspondence to: Masatoshi Kudo, MD PhD, Division of Gastroenterology and Hepatology, Department of Internal Medicine, Kinki University School of Medicine, 377-2 Ohno-Higashi Osaka-Sayama, 589-8511, Japan. m-kudo@med.kindai.ac.jp
Telephone: +81-72-3660221-3525 Fax: +81-72-3672880
Received: November 3, 2009
Revised: December 10, 2009
Accepted: December 21, 2009
Published online: December 31, 2009
Abstract

The success rate of percutaneous radiofrequency (RF) ablation for hepatocellular carcinoma (HCC) depends on correct targeting via an imaging technique. However, RF electrode insertion is not completely accurate for residual HCC nodules because B-mode ultrasound (US), color Doppler, and power Doppler US findings cannot adequately differentiate between treated and viable residual tumor tissue. Electrode insertion is also difficult when we must identify the true HCC nodule among many large regenerated nodules in cirrhotic liver. Two breakthroughs in the field of US technology, harmonic imaging and the development of second-generation contrast agents, have recently been described and have demonstrated the potential to dramatically broaden the scope of US diagnosis of hepatic lesions. Contrast-enhanced harmonic US imaging with an intravenous contrast agent can evaluate small hypervascular HCC even when B-mode US cannot adequately characterize tumor. Therefore, contrast-enhanced harmonic US can facilitate RF ablation electrode placement in hypervascular HCC, which is poorly depicted by B-mode US. The use of contrast-enhanced harmonic US in ablation therapy for liver cancer is an efficient approach.

Keywords: Contrast-enhanced harmonic ultrasound, Hepatocellular carcinoma, Radiofrequency ablation, Second generation microbubbles