Clinical utility of contrast-enhanced three-dimensional ultrasound imaging with Sonazoid: findings on hepatocellular carcinoma lesions

Objectives

We investigated clinical utility of contrast-enhanced three-dimensional ultrasound (CE 3D US) imaging with contrast medium Sonazoid for demonstrating characteristic enhancement of hepatocellular carcinoma (HCC).

Methods

Among 115 focal liver tumors undergoing CE 3D US imaging, 70 HCCs confirmed with contrast-enhanced multi-detector computed tomography, contrast-enhanced magnetic resonance imaging or histopathologic examination were retrospectively analyzed. CE 3D US imaging was performed using Autosweep 3D scan functionality in the early, middle and late phase, after bolus injection of 0.2 ml Sonazoid. The CE 3D tomographic images reconstructed in parallel slices and sonographic angiogram images were independently reviewed by two reviewers. Kappa values were used to assess inter-reviewers’ agreement.

Results

TUI images showed most of HCCs were detected with intratumoral vessels and early tumor enhancement in the early phase, expressed homogenous or heterogeneous tumor enhancement in the middle phase, and became hypoechoic or isoechoic in the late phase. The kappa values in the early, middle and late phase for inter-reviewer agreements regarding the characteristic enhancement of tumors were 0.817, 0.774, and 0.785. In addition, TUI images demonstrated satellite foci and tortuous tumor vessels in three orthogonal planes. Sonographic angiogram reconstructed by different rendering modes showed the vessels and tumor stain in spatial view. The spatial configuration of anatomic structures was revealed on basis of both TUI and sonographic angiogram images.

Conclusion

CE 3D US imaging, with spatial visualization, is clinically useful to exhibit the characteristic enhancement of HCC tumors objectively.     

Detection of focal liver lesions in cirrhotic liver using contrast-enhanced ultrasound

Patients with liver cirrhosis are at increased risk of hepatocellular carcinoma (HCC). Conventional or baseline ultrasound (BUS) is often used as the first-line tool for HCC surveillance or detection, but the accuracy of BUS in HCC detection or differentiation from other focal liver lesions (FLLs) is limited. Contrast-enhanced ultrasound (CEUS) represents a recent revolution in the field of ultrasonography and it has become increasingly important in the detection and evaluation of FLLs. In CEUS, HCC typically exhibits arterial hyper-enhancement and portal-venous washout represented by hypo-enhanced lesions in the portal venous and late phases. The detection rate of HCC was significantly higher with CEUS compared with BUS. Even regenerative or some dysplastic nodules may exhibit arterial hyper-enhancement as they are differentiated from HCC by its iso-enhancing pattern in portal and late phases. The contrast-enhancement patterns of other different types of benign and malignant FLLs, as well as their detection rates with CEUS, were also discussed.     

Screening for liver metastases in women with mammary carcinoma: comparison of contrast-enhanced ultrasound and magnetic resonance imaging

Objective

The objective of the present study was to compare conventional B-mode ultrasound (BMU), contrast-enhanced ultrasound (CEUS), and magnetic resonance imaging (MRI) in the detection of liver metastases at the primary staging and follow-up of women with histologically confirmed mammary carcinoma.

Patients and methods

Included in the study were 55 women (aged 57.5±11.0 years, range 27-75 years; mean disease duration 57.5 months, range 5-168 months); of these, 17 women were examined as part of primary staging (staging group) and 38 women at follow-up (follow-up group). All patients underwent BMU (Philips HDI 5000), CEUS (Philips HDI 5000; 4.8 ml SonoVue), and MRI (Siemens Avanto 1.5 T) of the liver.

Results

In the staging group (n=17), a mass was detected by BMU in 24% (n=4), by CEUS in 29% (n=5), and by MRI in 47% (n=8); masses suspicious for malignancy were identified in 6% of patients with BMU and in 12% each by CEUS and MRI. Malignancy was not confirmed in any case by cytology or surgery. In the follow-up group (n=38), masses were identified by MRI in 53% of patients with suspicion of malignancy in 18%. Malignancy was confirmed in 16% of cases identified at MRI, in 13% of cases identified with CEUS, and in 11% of cases identified with BMU. The Pearson coefficients of correlation were r=.29 (P=.03) for MRI vs. BMU; r=.42 (P=.002) for MRI vs. CEUS; and r=.75 (P≤.001) for BMU vs. CEUS. With respect to malignancy, the Pearson coefficients of correlation were r=.40 (P=.099) for BMU vs. MRI and r=.71 (P=.0009) for CEUS vs. MRI.

Conclusions

Beginning in tumor stage III, the use of CEUS and MRI is associated with a significantly greater benefit in the detection of malignant tumors of the liver compared with conventional BMU. BMU appears to be adequate for primary staging and the follow-up of lower tumor stages.     

Era of diagnostic and interventional ultrasound

It is an era of diagnostic and interventional ultrasound (US).Various new techniques such as three-dimensional US(3D US),interventional US,and contrastenhanced US(CEUS)have been introduced into clinical practice.Dr.Xu and his colleagues have taken advantage of these techniques and carried out a series of relevant studies.Their use of 3D US in the liver,gallbladder,liver tumor volumetry,guidance for ablation,and 3D CEUS has widened the application of 3D US in the clinic.They found that prognosis in patients with hepatocellular carcinoma(HCC)after thermal ablation with curative intent was determined by treatment response to ablation,pretreatment serum AFP,and liver function reserve.Tumor response to treatment was the most predictive factor for long-term survival.They compared the use of percutaneous microwave ablation and radiofrequency ablation for the treatment of HCC and found that both are effective methods in treating HCCs.The local tumor control,complications related to treatment, and long-term survival were equivalent for the two modalities.They first compared the enhancement patterns of HCC and intrahepatic cholangiocarcinoma(ICC)and proposed the diagnostic clues for ICC,liver angiomyolipoma(AML),gallbladder cancer,renal carcinoma,and renal AML,which have greatly enhanced the role ofCEUS in the clinic.They also evaluated the diagnostic performance of CEUS in characterizing complex cystic focal liver lesions and the agreement between two investigators with different experience levels;and found that CEUS is especially useful for the young investigator.They assessed the effect of anti-angiogenic gene therapy for HCC treated by microbubble-enhanced US exposure and concluded that gene therapy mediated by US exposure enhanced by a microbubble contrast agent may become a new treatment option for HCC.     

Focal liver lesions in cirrhosis: Role of contrast-enhanced ultrasonography

Contrast-enhanced ultrasound (CEUS) represents a great innovation for the evaluation of focal liver lesions (FLLs). The main advantage of CEUS is the real-time imaging examination and the very low toxicity in patients with renal failure. Liver cirrhosis has been recognized as a major risk factor for the onset of hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC). HCC in liver cirrhosis develops as the last step of a complex that leads to the gradual transformation from regenerative nodule through dysplastic nodule to HCC. In patients with liver cirrhosis, a surveillance program is recommended consisting of ultrasound (US) for detecting small focal lesions. A wide spectrum of benign and malignant lesions other than HCC may be found in the cirrhotic liver and their differentiation is important to avoid errors in staging diseases that may preclude potentially curative therapies. Several published studies have explored the value of CEUS in liver cirrhosis and they have been shown to have excellent diagnostic and prognostic performances for the evaluation of non-invasive and efficient diagnosis of FLLs in patients at high risk for liver malignancies. The purpose of this article is to describe and discuss CEUS imaging findings of FLLs including HCC and ICC, all of which occur in cirrhotic livers with varying prevalence.     

Role of contrast-enhanced ultrasound in decision support for diagnosis and treatment of hepatic artery thrombosis after liver transplantation

Objective

To assess role of contrast-enhanced ultrasound (CEUS) in decision support for diagnosis and treatment of hepatic artery thrombosis (HAT) after liver transplantation.

Materials and methods

Between January 2005 and January 2011, 605 patients underwent liver transplantation in our medical center. All the liver transplant recipients received Doppler ultrasound scanning and CEUS examination was performed in 45 patients with suspected HAT on Doppler ultrasound. Sensitivity, specificity, accuracy, positive predict value and negative predictive value of CEUS in diagnosing HAT were determined based on the results from angiography, surgery and clinical follow-up.

Results

Fourteen HATs, including one late HAT, were diagnosed by CEUS. Twelve HAT cases were confirmed by angiographic and/or surgical findings, while the late HAT and other 31 patients with negative CEUS finding were confirmed by the clinical follow-up. There was a false positive HAT diagnosed by CEUS in which angiography revealed a patent hepatic artery. The sensitivity, specificity, accuracy, positive predict value and negative predictive value of CEUS in diagnosing HAT were 100%, 96.9%, 97.8%, 92.9% and 100%, respectively. In our series of 605 liver transplants, the incidence and mortality of HAT was 2.2% (13/605) and 53.8% (7/13), respectively.

Conclusions

Our study demonstrates the important role of CEUS in decision support for diagnosis and treatment of HAT after liver transplantation. When HAT is suspected by Doppler ultrasound, CEUS shall immediately be performed to elucidate its nature. A negative CEUS finding shall avoid invasive angiography. Such as, CEUS may alter the clinical workflow on HAT detection after liver transplantation.     

超声造影技术评估宫颈癌预后应用价值研究

目的探讨超声造影(CEUS)技术评估宫颈癌预后的应用价值。方法选取2010年12月至2016年4月收治的宫颈癌患者40例,根据是否存在风险预后因素分为中-高风险组(15例)与低风险组(25例)。比较两组患者的CEUS表现与时间-强度曲线(TIC)参数,绘制受试者工作特征曲线(ROC)并计算增强强度(EI)最佳诊断阈值。结果宫颈癌CEUS表现以非均匀性高增强为主,两组增强水平与增强分布比较,差异无统计学意义(P>0.05);中-高风险组灌注缺损多于低风险组,差异有统计学意义(P<0.05)。两组增强时间(AT)与达峰时间(TTP)差异无统计学意义(P>0.05);中-高风险组峰值强度(PI)与增强强度(EI)高于低风险组,差异有统计学意义(P<0.05)。EI在最佳诊断阈值25.75 d B时,评估宫颈癌存在中-高风险预后因素的敏感度为93.3%、特异度为74.0%、准确度为77.5%。结论 CEUS技术在评估宫颈癌预后中具有一定的临床应用价值。     

Preoperative RFA simulation for liver cancer using a CT virtual ultrasound system

We developed a computed tomography (CT) virtual ultrasound system (CVUS) as an imaging system to support treatment under percutaneous ultrasound (US) guidance. This prototype clinical system, produced in collaboration with Tokyo Medical University, uses display software developed by Toshiba Medical Systems. We examined the utility of this system by scheduling treatment plans preoperatively and simulating puncture and radiofrequency ablation (RFA) for liver cancer. The study enrolled 51 liver cancer patients with 66 nodules 0.8-8cm in diameter in which RFA was performed between June 2004 and December 2004. Virtual US and multiplanar reconstruction (MPR) images were constructed on the basis of DICOM CT data and puncture and ablation of liver cancer were simulated. The following were evaluated: (1) how to avoid complications and determine an appropriate puncture route by simulating puncture with C-mode MPR images; (2) determination of the three-dimensional location of the tumor for ablation, as well as the adjacent organs and vessels, by MPR rotation 360 degrees around the center of the tumor (center lock); and (3) how to determine the center and volume of ablation and avoid injuries to nearby organs and vessels by simulating ablation procedures. C -mode MPR images were effective for (1) determining and modifying the puncture route in 35 of 51 cases (69.6%) and (2) determining the spatial location of vessels and nearby organs in 50 of 51 cases (98.0%) by the center lock; and (3) simulating the ablation helped determine the center and volume of ablation by avoiding injuries to vessels and nearby organs in 45 or 51 cases (88.2%). Taken together, the CVUS allowed easy simulation of local treatment of liver cancer under US guidance using CT data alone and the preoperative simulation predicted an improvement in the safety of local therapy of liver cancer.     

Focal liver lesions: role of contrast-enhanced ultrasound

The introduction of microbubble contrast agents and the development of contrast-specific techniques have opened new possibilities in liver imaging. Initially, only intermittent imaging with Doppler detection was available. Second-generation contrast agents and low mechanical index real-time scanning techniques are decisive advances that enable convenient liver examinations with high sensitivity and specificity. Hepatic lesions usually show typical perfusion and enhancement patterns through the various contrast phases, which help their characterization. Several published studies and the daily clinical routine show that, as opposed to conventional ultrasound (US), contrast-enhanced US can substantially improve detection and differentiation of focal liver lesions. Today, contrast-enhanced US is the dynamic imaging modality of choice for differentiation of focal liver lesions. Contrast uptake patterns of the most relevant liver lesions, as well as important clinical indications are presented and discussed.     

超声造影在肝癌非手术治疗疗效评价中的应用

肝癌非手术治疗后,疗效的评价对指导肝癌的治疗具有重要意义。近几年来随着新型超声造影剂的不断涌现和造影成像技术的迅速发展,超声造影技术已成为临床评价肝癌非手术治疗疗效的重要手段。现将超声造影在各种常用肝癌非手术治疗方法疗效评价中的应用价值作如下综述。     

Evaluation of the therapeutic efficacy of high-intensity focused ultrasound ablation of hepatocellular carcinoma by three-dimensional sonography with a perflubutane-based contrast agent

Objective

We performed contrast-enhanced three-dimensional sonography (CE 3D US) with a perflubutane-based contrast agent to immediately evaluate the completeness of ablation of small hepatocellular carcinoma (HCC) lesions by extracorporeal high-intensity focused ultrasound (HIFU).

Subjects and methods

Twenty-one HCC lesions were treated by a single ultrasound-guided HIFU ablation session, and CE 3D US was performed before, immediately after, and 1 week, and 1 month after HIFU, and contrast-enhanced CT (CE CT) or contrast-enhanced MRI (CE MRI) was performed before HIFU, 1 week and 1 month after HIFU, and during the follow-up period.

Results

Immediately and 1 month after HIFU, 17 lesions were evaluated as adequately ablated by CE 3D US, and the other 4 lesions as residual tumors. One month after HIFU, 18 were evaluated as adequately ablated by CE CT or CE MRI, and the other 3 as residual tumors. The evaluation by CE 3D US immediately after HIFU and by CE CT or CE MRI 1 month after HIFU was concordant with 20 lesions. The kappa value for agreement between the findings of CE 3D US and other modalities by two blinded observers was 0.83. When the 1-month CE CT or CE MRI findings were used as the reference standard, the sensitivity, specificity, and accuracy of CE 3D US immediately after HIFU for the diagnosis of the adequate ablation were 100%, 75%, and 95%, respectively.

Conclusion

CE 3D US appears to be a useful method for immediate evaluation of therapeutic efficacy of HIFU ablation of HCC lesions.     

常规超声联合超声造影成像对宫颈癌诊断及分期初步研究

目的探讨常规超声联合超声造影检查(CEUS)在诊断宫颈癌及分期中的应用价值。方法对36例临床诊断为宫颈癌的患者,在术前进行超声及CEUS根据肿块部位、大小、对周围组织的侵犯情况进行分期,并与手术病理分期对照,分析其诊断宫颈癌分期的准确性。结果常规超声联合CEUS诊断宫颈癌Ⅰb、Ⅱ、Ⅲ、Ⅳ期准确率分别为100.0%(4/4)、75.0%(9/12)、92.9%(13/14)和100.0%(6/6),总准确率达88.9%(32/36),两者检查结果高度一致(Kappa值=0.866)。结论超声联合CEUS诊断宫颈癌分期的准确率较高,可以作为主要影像学检查方法之一。     

肝细胞肝癌的超声造影参数成像分析研究

目的探讨超声造影参数成像分析在肝细胞肝癌(HCC)诊断中的应用价值。方法分析68例HCC的超声造影资料,应用SonoLiverR CAP定量分析软件,以HCC与周围肝实质的增强水平差值为参数进行动态血管模型(dy-namic vascular pattern,DVP)重建,分析结果以DVP彩色编码图、DVP曲线图及定量参数显示,并进行分型及统计学分析。结果 DVP彩色编码图:消退型,未消退型分别占88.24%(60/68)和11.76%(8/68);DVP曲线图:消退型,未消退型分别占83.82%(57/68)和16.18%(11/68)。定量参数显示HCC与周围肝实质的峰值强度、上升时间、达峰时间和平均渡越时间的差异均具有统计学意义(P<0.05)。结论超声造影参数成像可直观、量化的显示病灶变化,为HCC诊断提供更为准确的定量信息。     

超声造影引导在肝占位性病变穿刺活检中应用价值

目的探讨超声造影引导在肝占位性病变穿刺活检中的临床应用价值。方法回顾性分析2014年1月至2016年12月行穿刺活检的102例肝占位性病变患者临床资料,其中,A组患者(n=53)采取超声造影引导行穿刺活检;B组患者(n=49)采取超声引导行穿刺活检,所取组织满足病理诊断为取材成功。比较两组患者穿刺成功率、定性诊断率。结果两组患者均全部穿刺成功,穿刺成功率均为100.0%。A组53例患者取材均满足病理诊断,定性诊断率100.0%;B组定性诊断率为83.7%(41/49)。A组的定性诊断率明显优于B组,差异有统计学意义(P<0.05)。结论超声造影引导下行肝占位性病变穿刺活检,能清楚显示肿瘤活性区域、坏死区域及液化区域,更为准确的定位取材,降低假阴性的风险,具有较高的临床应用价值。     

Discrepancy of contrast-enhanced ultrasonographic pattern with two contrast agents in steatohepatitic subtype hepatocellular carcinoma: A case report

Contrast-enhanced ultrasound (CEUS) is one of the important imaging modalities for diagnosis of hepatocellular carcinoma (HCC). Sonovue and Sonazoid are the third-generation of ultrasound contrast agents that have been commercialized and widely used in clinical applications. This study introduces the imaging differences between these two agents in vascular phases for the first time. A 54-year-old man clinical suspected liver cancer. He had chronic hepatitis B for more than 20 years. The result of alpha-fetoprotein was 36.45μg/L (normal< 20μg/L). The imaging pattern of CEUS with Sonovue was “fast-in and fast-out” performance, while the pattern of “fast-out” was absent after portal phase with Sonazoid, even in Kupffer phase. The lesion was diagnosed as lipid-rich HCC by contrast-enhanced MRI. After liver resection, pathology revealed that it was hepatocellular carcinoma contained poor-differentiated steatohepatitis subtype and moderate-differentiated microtrabecular subtype. The imaging difference mainly existed in the part of steatohepatitis subtype. Steatohepatitis subtype HCC can be showed as “fast-in and no wash-out” characteristic in Sonazoid CEUS. Though the mechanism remains not fully clarified, this different enhancing pattern may provide a potential for the supplement of the guidelines and differential of steatohepatitis subtype HCC.     

Use of contrast-enhanced ultrasonography with a perflubutane-based contrast agent performed one day after transarterial chemoembolization for the early assessment of residual viable hepatocellular carcinoma

Objective

We evaluated the efficacy of contrast-enhanced ultrasonography (US), compared with contrast-enhanced computed tomography (CT), for early assessments after transarterial chemoembolization (TACE) for the treatment of hypervascular hepatocellular carcinoma (HCC) lesions.

Subjects and methods

Thirty-two patients with 59 HCC lesions who were scheduled to receive TACE were enrolled in this prospective study. TACE was performed by injecting a mixture of iodized oil and miriplatin hydrate, followed by a gelatin sponge. Digital subtraction angiography (DSA) and/or contrast-enhanced CT were performed 2–6 months after TACE and were used as the reference standard for residual HCC; the detection rates for residual viable HCC using contrast-enhanced US with a perflubutane-based contrast agent and a high mechanical index (MI) mode performed one day after TACE were also compared with those obtained using contrast-enhanced CT performed one month after TACE. The comparisons were made using the McNemar test.

Results

Forty-seven (79.7%) of the 59 HCC lesions were diagnosed as having residual viability based on DSA and contrast-enhanced CT findings obtained 2–6 months after TACE. Eight (17.0%) of the 47 HCC lesions that were diagnosed as having residual viability using one-day contrast-enhanced US were not detected using one-month contrast-enhanced CT because of artifacts produced by the high attenuation of the iodized oil. The detection rate for residual HCC lesions using one-day contrast-enhanced US (95.7%, 45/47) was significantly higher than that using one-month contrast-enhanced CT (78.7%, 37/47) (P < 0.05).

Conclusion

Contrast-enhanced US performed one day after TACE is more sensitive than contrast-enhanced CT performed one month after TACE for detecting residual viable HCC.     

Small nodules (1-2 cm) in liver cirrhosis: characterization with contrast-enhanced ultrasound

Objective

To determine the diagnostic efficacy of arterial phase contrast-enhanced ultrasound (CEUS) for characterizing small hepatic nodules (1-2 cm) in patients with high-risk for hepatocellular carcinoma (HCC).

Materials and methods

Over 12 months, CEUS was performed in 59 patients at high-risk for HCC with small hepatic nodules (1-2 cm; mean, 1.5 cm). Based only on arterial phase (<45 s) vascular intensity and pattern, lesions were prospectively diagnosed as HCC if there was hypervascularity without known features of hemangioma. The diagnosis of HCC was made regardless of the presence or absence of washout. Verification of diagnosis was made by liver transplantation (n = 13), biopsy (n = 12), resection (n = 3) or clinical and imaging follow-up for at least 12 months (n = 31).

Results

At of the time of CEUS, the 59 nodules were diagnosed as HCC in 26 and benign lesions in 33, including 20 regenerative/dysplastic nodules (RN/DN), 11 hemangiomas, and 2 focal fat sparing. All 26 nodules with arterial phase hypervascularity without hemangioma-like features were HCC. However, CEUS misdiagnosed HCC as RN/DN in 4 cases with arterial iso- (n = 3) or hypovascularity (n = 1). CEUS correctly diagnosed all 11 hemangiomas. The sensitivity, specificity, and accuracy of CEUS for diagnosing HCC were 86.7, 100, and 93.2%.

Conclusions

Arterial phase vascular intensity and pattern of CEUS are highly accurate for the diagnosis of small (1-2 cm) HCC and hemangioma in liver cirrhosis. On CEUS, arterial phase hypervascularity without a hemangioma-pattern alone may be sufficient for diagnosis of small HCC. Infrequent iso/hypovascular HCC may erroneously suggest RN/DN necessitating biopsy or close follow-up.     

Contrast-enhanced ultrasound in diagnosis and characterization of focal hepatic lesions

The extensive use of imaging techniques in differential diagnosis of abdominal conditions and screening of hepatocellular carcinoma in patients with chronic hepatic diseases, has led to an important increase in identification of focal liver lesions. The development of contrast-enhanced ultrasound (CEUS) opens a new window in the diagnosis and follow-up of these lesions. This technique offers obvious advantages over the computed tomography and magnetic resonance, without a decrease in its sensitivity and specificity. The new second generation contrast agents, due to their intravascular distribution, allow a continuous evaluation of the enhancement pattern, which is crucial in characterization of liver lesions. The dual blood supply in the liver shows three different phases, namely arterial, portal and late phases. The enhancement during portal and late phases can give important information about the lesion's behavior. Each liver lesion has a different enhancement pattern that makes possible an accurate approach to their diagnosis. The role of emerging techniques as a contrast-enhanced three-dimensional US is also discussed. In this article, the advantages, indications and technique employed during CEUS and the different enhancement patterns of most benign and malignant focal liver lesions are discussed.     

Role for contrast-enhanced ultrasound in assessing complications after kidney transplant

Kidney transplantation (KT) is an effective treatment for end-stage renal disease. Despite their rate has reduced over time, post-transplant complications still represent a major clinical problem because of the associated risk of graft failure and loss. Thus, post-KT complications should be diagnosed and treated promptly. Imaging plays a pivotal role in this setting. Grayscale ultrasound (US) with color Doppler analysis is the first-line imaging modality for assessing complications, although many findings lack specificity. When performed by experienced operators, contrast-enhanced US (CEUS) has been advocated as a safe and fast tool to improve the accuracy of US. Also, when performing CEUS there is potentially no need for further imaging, such as contrast-enhanced computed tomography or magnetic resonance imaging, which are often contraindicated in recipients with impaired renal function. This technique is also portable to patients’ bedside, thus having the potential of maximizing the cost-effectiveness of the whole diagnostic process. Finally, the use of blood-pool contrast agents allows translating information on graft microvasculature into time-intensity curves, and in turn quantitative perfusion indexes. Quantitative analysis is under evaluation as a tool to diagnose rejection or other causes of graft dysfunction. In this paper, we review and illustrate the indications to CEUS in the post-KT setting, as well as the main CEUS findings that can help establishing the diagnosis and planning the most adequate treatment.     

Contrast-enhanced harmonic ultrasound imaging in ablation therapy for primary hepatocellular carcinoma

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.