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World J Radiol. Feb 28, 2010; 2(2): 68-82
Published online Feb 28, 2010. doi: 10.4329/wjr.v2.i2.68
Contrast enhanced ultrasound of hepatocellular carcinoma
Kazushi Numata, Wen Luo, Manabu Morimoto, Masaaki Kondo, Yosuke Kunishi, Tomohiko Sasaki, Akito Nozaki, Katsuaki Tanaka
Kazushi Numata, Wen Luo, Manabu Morimoto, Masaaki Kondo, Yosuke Kunishi, Tomohiko Sasaki, Akito Nozaki, Katsuaki Tanaka, Gastroenterological Center, Yokohama City University Medical Center, 4-57 Urafune-cho, Minami-ku, Yokohama, Kanagawa 232-0024, Japan
Wen Luo, Department of Ultrasound, Xijing Hospital, Fourth Military Medical University, No. 15, Changle Xi Road, Xi’an 710032, Shaanxi Province, China
Author contributions: Numata K designed the review; Numata K, Morimoto M, Kondo M, Nozaki A, Kunishi Y, Sasaki T, Nozaki A and Tanaka K contributed to collecting patient data; Numata K and Luo W wrote the manuscript.
Correspondence to: Kazushi Numata, MD, Gastroenterological Center, Yokohama City University Medical Center, 4-57 Urafune-cho, Minami-ku, Yokohama, Kanagawa 232-0024, Japan. kz-numa@urahp.yokohama-cu.ac.jp
Telephone: +81-45-2615656 Fax: +81-45-2619492
Received: February 10, 2010
Revised: February 21, 2010
Accepted: February 26, 2010
Published online: February 28, 2010
Abstract

Sonazoid (Daiichi Sankyo, Tokyo, Japan), a second-generation of a lipid-stabilized suspension of a perfluorobutane gas microbubble contrast agent, has been used clinically in patients with liver tumors and for harmonic gray-scale ultrasonography (US) in Japan since January 2007. Sonazoid-enhanced US has two phases of contrast enhancement: vascular and late. In the late phase of Sonazoid-enhanced US, we scanned the whole liver using this modality at a low mechanical index (MI) without destroying the microbubbles, and this method allows detection of small viable hepatocellular carcinoma (HCC) lesions which cannot be detected by conventional US as perfusion defects in the late phase. Re-injection of Sonazoid into an HCC lesion which previously showed a perfusion defect in the late phase is useful for confirming blood flow into the defects. High MI intermittent imaging at 2 frames per second in the late phase is also helpful in differentiation between necrosis and viable hypervascular HCC lesions. Sonazoid-enhanced US by the coded harmonic angio mode at a high MI not only allows clear observation of tumor vessels and tumor enhancement, but also permits automatic scanning with Sonazoid-enhanced three dimensional (3D) US. Fusion images combining US with contrast-enhanced CT or contrast-enhanced MRI have made it easy to detect typical or atypical HCC lesions. By these methods, Sonazoid-enhanced US can characterize liver tumors, grade HCC lesions histologically, recognize HCC dedifferentiation, evaluate the efficacy of ablation therapy or transcatheter arterial embolization, and guide ablation therapy for unresectable HCC. This article reviews the current developments and applications of Sonazoid-enhanced US and Sonazoid-enhanced 3D US for diagnosing and treating hepatic lesions, especially HCC.

Keywords: Sonazoid; Contrast-enhanced ultrasonography; Contrast-enhanced three-dimensional ultrasonography; Hepatic tumor; Hepatocellular carcinoma; Fusion image