Contrast-enhanced ultrasonography findings using a perflubutane-based contrast agent in patients with early hepatocellular carcinoma

Pitfalls and strategies of Sonazoid enhanced ultrasonography in differentiating metastatic and benign hepatic lesions

OBJECTIVE

This article aims to clarify pitfalls and find strategies for the detecting and diagnosing hyperechoic liver metastases (LMs) using Sonazoid-contrast enhanced ultrasonography (Sonazoid-CEUS).

METHODS

This study was a prospective self-controlled study. Patients with hepatic lesions suspected as LMs or benign lesions were included in the study. Baseline ultrasonography (BUS) and Sonazoid-CEUS were performed on every patient. Characteristics of LMs and benign nodules were compared by chi-square test and fisher test. Factors influenced the CEUS were demonstrated by univariate analysis and multivariate logistic regression analysis.

RESULTS

54 patients were included in this study. CEUS found additional 75 LMs from 19 patients in Kupffer phase. We found hyperechoic focal liver lesions and deep seated in liver are main confounding factors in CEUS diagnosis. Sensitivity would be improved from 16.67% to 78.57%, negative predictive value (NPV) would be improved from 28.57% to 76.92% and accuracy would be improved from 37.5% to 87.50% when using rapid "wash-in" and "wash-out" as main diagnostic criteria.

CONCLUSIONS

Hyperechoic LMs especially deeply seated ones are usually not shown typical "black hole" sign in Kupffer phase. Quickly "wash-in and wash out" shows high accuracy in diagnosing malignant nodules. We highly recommend CEUS as a routing exam to detect and diagnose LMs.

Usefulness of contrast-enhanced ultrasonography for biliary tract disease

Conventional ultrasonography (US) for biliary tract disease shows high time and spatial resolution. In addition, it is simple and minimally invasive, and is selected as a first-choice examination procedure for biliary tract disease. Currently, contrast-enhanced US (CEUS), which facilitates the more accurate assessment of lesion blood flow in comparison with color and power Doppler US, is performed using a second-generation ultrasonic contrast agent. Such agents are stable and provide a timeline for CEUS diagnosis. Gallbladder lesions are classified into three types: gallbladder biliary lesion (GBL), gallbladder polypoid lesion (GPL), and gallbladder wall thickening (GWT). Bile duct lesions can also be classified into three types: bile duct biliary lesion (BBL), bile duct polypoid lesion (BDPL), and bile duct wall thickening (BDWT). CEUS facilitates the differentiation of GBL/BBL from tumorous lesions based on the presence or absence of blood vessels. In the case of GPL, it is important to identify a vascular stalk attached to the lesion. In the case of GWT, the presence or absence of a non-contrast-enhanced area, the Rokitansky-Aschoff sinus, and continuity of a contrast-enhanced gallbladder wall layer are important for differentiation from gallbladder cancer. In the case of BDWT, it is useful to evaluate the contour of the contrast-enhanced medial layer of the bile duct wall for differentiating IgG4-related sclerosing cholangitis from primary sclerosing cholangitis. CEUS for ampullary carcinoma accurately reflects histopathological findings of the lesion. Evaluating blood flow in the lesion, continuity of the gallbladder wall, and contour of the bile duct wall via CEUS provides useful information for the diagnosis of biliary tract disease.

Current Imaging Diagnosis of Hepatocellular Carcinoma

Simple Summary

The role of imaging in the management of hepatocellular carcinoma (HCC) has significantly evolved and expanded beyond the plain radiological confirmation of the tumor based on the typical appearance in a multiphase contrast-enhanced CT or MRI examination. The introduction of hepatobiliary contrast agents has enabled the diagnosis of hepatocarcinogenesis at earlier stages, while the application of ultrasound contrast agents has drastically upgraded the role of ultrasound in the diagnostic algorithms. Newer quantitative techniques assessing blood perfusion on CT and MRI not only allow earlier diagnosis and confident differentiation from other lesions, but they also provide biomarkers for the evaluation of treatment response. As distinct HCC subtypes are identified, their correlation with specific imaging features holds great promise for estimating tumor aggressiveness and prognosis. This review presents the current role of imaging and underlines its critical role in the successful management of patients with HCC.

Abstract

Hepatocellular carcinoma (HCC) is the fourth leading cause of cancer related death worldwide. Radiology has traditionally played a central role in HCC management, ranging from screening of high-risk patients to non-invasive diagnosis, as well as the evaluation of treatment response and post-treatment follow-up. From liver ultrasonography with or without contrast to dynamic multiple phased CT and dynamic MRI with diffusion protocols, great progress has been achieved in the last decade. Throughout the last few years, pathological, biological, genetic, and immune-chemical analyses have revealed several tumoral subtypes with diverse biological behavior, highlighting the need for the re-evaluation of established radiological methods. Considering these changes, novel methods that provide functional and quantitative parameters in addition to morphological information are increasingly incorporated into modern diagnostic protocols for HCC. In this way, differential diagnosis became even more challenging throughout the last few years. Use of liver specific contrast agents, as well as CT/MRI perfusion techniques, seem to not only allow earlier detection and more accurate characterization of HCC lesions, but also make it possible to predict response to treatment and survival. Nevertheless, several limitations and technical considerations still exist. This review will describe and discuss all these imaging modalities and their advances in the imaging of HCC lesions in cirrhotic and non-cirrhotic livers. Sensitivity and specificity rates, method limitations, and technical considerations will be discussed.

Contrast-enhanced ultrasonography for blood flow detection in hepatocellular carcinoma during lenvatinib therapy

PURPOSE

Blood flow reduction after initiation of lenvatinib therapy may not always indicate tumor necrosis. This study aimed to compare the blood flow detectability of contrast-enhanced ultrasonography (CEUS), contrast-enhanced computed tomography (CT), and contrast-enhanced magnetic resonance imaging (MRI) in hepatocellular carcinoma (HCC) during lenvatinib therapy.

METHODS

A total of 12 cases underwent CEUS and contrast-enhanced CT/MRI within 2 weeks during lenvatinib therapy. Vascularity on CEUS and CT/MRI was compared.

RESULTS

At the time of CEUS examination, the median period from the start of lenvatinib was 227 ± 210 (31-570) days. CEUS showed hyperenhancement in eight cases (66.7%), hypoenhancement in two cases (16.7%), and no enhancement in one case (8.3%), while CT/MRI showed hyperenhancement in one case (8.3%), ring enhancement in three cases (25.0%), and hypoenhancement in eight cases (66.7%) (p = 0.007). Transarterial chemoembolization (n = 3), radiofrequency ablation (n = 2), and stereotactic body radiation therapy (n = 2) were performed after blood flow detection by CEUS.

CONCLUSIONS

The viability of the HCC should be confirmed using CEUS when contrast-enhanced CT/MRI reveals lesion hypoenhancement during lenvatinib therapy.

Noninvasive Diagnosis of Hepatocellular Carcinoma on Sonazoid-Enhanced US: Value of the Kupffer Phase

The aim of this study was to compare the diagnostic performance of Contrast-Enhanced US Liver Imaging Reporting and Data System (CEUS LI-RADS) version 2017, which includes portal- and late-phase washout as a major imaging feature, with that of modified CEUS LI-RADS, which includes Kupffer-phase findings as a major imaging feature. Participants at risk of hepatocellular carcinoma (HCC) with treatment-naïve hepatic lesions (≥1 cm) were recruited and underwent Sonazoid-enhanced US. Arterial phase hyperenhancement (APHE), washout time, and echogenicity in the Kupffer phase were evaluated using both criteria. The diagnostic performance of both criteria was analyzed using the McNemar test. The evaluation was performed on 102 participants with 102 lesions (HCCs (n = 52), non-HCC malignancies (n = 36), and benign (n = 14)). Among 52 HCCs, non-rim APHE was observed in 92.3% (48 of 52). By 5 min, 73.1% (38 of 52) of HCCs showed mild washout, while by 10 min or in the Kupffer phase, 90.4% (47 of 52) of HCCs showed hypoenhancement. The sensitivity (67.3%; 35 of 52; 95% CI: 52.9%, 79.7%) of modified CEUS LI-RADS criteria was higher than that of CEUS LI-RADS criteria (51.9%; 27 of 52; 95% CI: 37.6%, 66.0%) (p = 0.0047). In conclusion, non-rim APHE with hypoenhancement in the Kupffer phase on Sonazoid-enhanced US is a feasible criterion for diagnosing HCC.

Imaging Diagnosis of HCC: Future directions with special emphasis on hepatobiliary MRI and contrast-enhanced ultrasound

Hepatocellular carcinoma (HCC) is a unique cancer entity that can be noninvasively diagnosed using imaging modalities without pathologic confirmation. In 2018, several major guidelines for HCC were updated to include hepatobiliary contrast agent magnetic resonance imaging (HBA-MRI) and contrast-enhanced ultrasound (CEUS) as major imaging modalities for HCC diagnosis. HBA-MRI enables the achievement of high sensitivity in HCC detection using the hepatobiliary phase (HBP). CEUS is another imaging modality with real-time imaging capability, and it is reported to be useful as a second-line modality to increase sensitivity without losing specificity for HCC diagnosis. However, until now, there is an unsolved discrepancy among guidelines on whether to accept “HBP hypointensity” as a definite diagnostic criterion for HCC or include CEUS in the diagnostic algorithm for HCC diagnosis. Furthermore, there is variability in terminology and inconsistencies in the definition of imaging findings among guidelines; therefore, there is an unmet need for the development of a standardized lexicon. In this article, we review the performance and limitations of HBA-MRI and CEUS after guideline updates in 2018 and briefly introduce some future aspects of imaging-based HCC diagnosis.

Perfluorobutane contrast-enhanced ultrasonography for the diagnosis of HCC: a systematic review and meta-analysis

OBJECTIVES

Perfluorobutane ultrasound contrast agent as a new type of contrast agent has a good performance in the diagnosis of hepatocellular carcinoma (HCC). This study aim to evaluate the accuracy and reliability of Perfluorobutane contrast-enhanced ultrasonography (P-CEUS) in the diagnosis of HCC with a systematic review and meta-analysis.

METHODS

Web of Science, EMBASE, Cochrane, Clinical Key, Wan Fang, CBM and CNKI databases were systematically searched and checked for studies using P-CEUS in HCC, from 2007 to 2020. Data necessary to construct 2 × 2 contingency tables were extracted from included studies. The QUADAS tool was utilized to assess the methodologic quality of the studies. Meta-analysis included data pooling, subgroup analyses, meta-regression and investigation of publication bias was comprehensively performed.

RESULTS

Nine studies were included in this meta-analysis and the overall diagnostic accuracy in characterization of HCC was as follows: pooled sensitivity, 0.90 (95% confidence interval: 0.82-0.95); pooled specificity, 0.97 (0.93-0.98); pooled positive likelihood ratio, 27.2 (14.1 to - 52.3); and pooled negative likelihood ratio, 0.10 (0.06-0.18). The area under the comprehensive receiving operation characteristic curve was 0.98 (0.97-0.99).

CONCLUSION

The sensitivity and specificity of P-CEUS are more valuable than other imaging techniques (such as computer tomography or magnetic resonance imaging). However, due to the large differences in the data samples collected in this study, statistical heterogeneity results. P-CEUS can significantly improve the diagnostic efficiency of previous contrast-enhanced ultrasound for HCC. PROSPERO registration number: PROSPERO (CRD42020200040).

Liver Injury and Use of Contrast-Enhanced Ultrasound for Evaluating Intrahepatic Recurrence in a Case of TACE-Refractory Hepatocellular Carcinoma Receiving Atezolizumab-Bevacizumab Combination Therapy: A Case Report

A 67-year-old male with type 2 diabetes (T2DM) was diagnosed with postoperative intrahepatic recurrence for hepatocellular carcinoma (HCC). Nine sessions of transarterial chemoembolization (TACE) proved ineffective, and the patient was diagnosed as having TACE-refractory disease and received seven cycles of atezolizumab-bevacizumab combination therapy. After that, the patient developed hyperglycemia with the HbA1c elevation and the marked fasting serum C-peptide reduction and was diagnosed with developed immune-mediated diabetes (IMD) (T2DM exacerbation with insulin-dependent diabetes development). Subsequently, the hepatobiliary enzyme levels, which were high before the systemic therapy, worsened. Thus, we clinically diagnosed an exacerbation of liver injury due to TACE-induced liver injury complicated by drug-induced liver injury such as immune-mediated hepatotoxicity (IMH). Meanwhile, after contrast-enhanced computed tomography revealed complete response, contrast-enhanced ultrasound was performed to assess intrahepatic recurrence. We found that the latter modality allowed earlier and more definitive diagnosis of intrahepatic recurrence of HCC. Subsequently, despite systemic therapy discontinuation and steroids administration, the liver injury worsened, and the patient died. The autopsy revealed intrahepatic recurrence of HCC and extensive arterial obstruction by the beads used for TACE within the liver, which indicated that disturbed circulation was the primary cause of the liver injury and histopathologically confirmed IMD, but not IMH.

A study on the inconsistency of arterial phase hypervascularity detection between contrast-enhanced ultrasound using sonazoid and gadolinium-ethoxybenzyl-diethylenetriamine penta-acetic acid magnetic resonance imaging of hepatocellular carcinoma lesions

PURPOSE

By analyzing possible factors contributing to imaging misevaluation of arterial phase (AP) vascularity, we aimed to provide a more proper way to detect AP hypervascularity of hepatocellular carcinomas (HCCs) using the noninvasive imaging modalities magnetic resonance imaging (MRI) and contrast-enhanced ultrasound (CEUS).

METHODS

We retrospectively recruited 164 pathologically confirmed HCC lesions from 128 patients. Using CEUS with Sonazoid (SCEUS) and gadolinium-ethoxybenzyl-diethylenetriamine penta-acetic acid MRI (EOB-MRI), AP vascularity of the lesions was evaluated and inconsistencies in interpretation were examined. Indicators of margin, echogenicity, and halo and mosaic signs of lesions on grayscale US; depth of lesions on SCEUS; and tumoral homogeneity, signal contrast ratio of lesions to the surrounding area on precontrast and AP images on EOB-MRI, and histological grade were investigated.

RESULTS

When precontrast images were used to adjust the AP enhancement ratio, the proportion of inconsistent interpretations of AP vascularity declined from 26.2% (43/164; 29 non-hypervascularity instances using EOB-MRI and 14 using SCEUS) to 16.5% (27/164; 7 using EOB-MRI and 20 using SCEUS). Greater lesion depth (P = 0.017), ill-defined tumoral margin (P = 0.028), absence of halo sign (P = 0.034), and histologically early HCC (P = 0.007) on SCEUS, and small size (P = 0.012) and heterogeneity (P = 0.013) of lesions and slight enhancement (low AP enhancement ratio) (P = 0.018 and 0.009 before and after adjustment) on EOB-MRI, may relate to undetectable hypervascularity.

CONCLUSIONS

SCEUS and EOB-MRI may show discrepancies in evaluating AP vascularity in the case of deep, ill-defined, heterogeneous, slightly enhanced lesions, and histologically early HCCs. We recommend adjusting AP with precontrast images in EOB-MRI, and combining both modalities to detect hypervascularity.

Early hemodynamics of hepatocellular carcinoma using contrast-enhanced ultrasound with Sonazoid: focus on the pure arterial and early portal phases

To clarify the early hemodynamics of hepatocellular carcinoma (HCC), we defined the early portal phase of contrast-enhanced ultrasound (CEUS) and examined the reliability of this modality for determining HCC differentiation. Starting in 2007, we performed Sonazoid CEUS in 146 pathologically confirmed hepatic nodules; 118 HCC (8 poorly [Pd], 73 moderately [Md] and 37 well-differentiated [Wd]) and 28 benign nodules. We focused on the pure arterial and early portal phases up to 45 seconds after Sonazoid injection, and then the subsequent phase up to 30 minutes. We calculated covariance-adjusted sensitivities for nodule enhancement combinations of these three phases. Nodule enhancements were divided into hypo, iso and hyper. A positive predictive value of 100% was obtained for the following patterns: iso-iso-hypo, hypo-iso-iso, and hypo-hypo-hypo for Wd, hyper-iso-hypo and hyper-hypo-hypo for Md, hypo-hyper-hypo for Pd, and hyper-hyper-hyper for benign nodules. In Wd HCC (early HCC), there were seven enhancement patterns, thought to be characterized by various hemodynamic changes from early to advanced HCC. Two patterns allowing a diagnosis of Wd HCC were hypo in the pure arterial phase. Subsequent iso-enhancement in the early portal phase indicated a portal blood supply. Decreased enhancement in the early portal phase allows a diagnosis of Md HCC. However, gradual enhancement observed from the pure arterial to the early portal phase allows a diagnosis of Pd HCC. Therefore, even in the early portal phase, hemodynamic changes were visible not only in Wd but also in Md and Pd HCC. In conclusion, with division of the early phase hemodynamics into pure arterial and early portal phases, CEUS can provide information useful for determining the likely degree of HCC differentiation and for distinguishing early stage HCC from benign nodules.

Diagnostic Value of Imaging Methods in the Histological Four Grading of Hepatocellular Carcinoma

We attempted to establish an ultrasound (US) imaging-diagnostic system for histopathological grades of differentiation of hepatocellular carcinoma (HCC). We conducted a retrospective study of histopathologically confirmed 200 HCCs, classified as early (45 lesions), well- (31 lesions), moderately (68 lesions) or poorly differentiated (diff.) (56 lesions) HCCs. We performed grayscale US to estimate the presence/absence of halo and mosaic signs, Sonazoid contrast-enhanced US (CEUS) to determine vascularity (hypo/iso/hyper) of lesion in arterial and portal phase (PP), and echogenicity of lesion in post-vascular phase (PVP). All findings were of significance for the diagnosis of some (but not all) histological grades (p < 0.001–0.05). Combined findings with a relatively high diagnostic efficacy for early, poorly and moderately diff. HCC were a combination of absence of halo sign and isoechogenicity in PVP of CEUS (accuracy: 93.0%, AUC: 0.908), hypovascularity in PP (accuracy: 78.0%, area under the curve (AUC): 0.750), and a combination of isovascularity in PP and hypoechogenicity in PVP (accuracy: 75.0%, AUC: 0.739), respectively. On the other hand, neither any individual finding nor any combination of findings yielded an AUC of over 0.657 for the diagnosis of well-diff. HCC. Our study provides encouraging data on Sonazoid CEUS in the histological differential diagnosis of HCC, especially in early HCC, and the effectiveness of this imaging method should be further proved by prospective, large sample, multicenter studies.

The AFSUMB Consensus Statements and Recommendations for the Clinical Practice of Contrast-Enhanced Ultrasound using Sonazoid

The first edition of the guidelines for the use of ultrasound contrast agents was published in 2004, dealing with liver applications. The second edition of the guidelines in 2008 reflected changes in the available contrast agents and updated the guidelines for the liver, as well as implementing some nonliver applications. The third edition of the contrast-enhanced ultrasound (CEUS) guidelines was the joint World Federation for Ultrasound in Medicine and Biology-European Federation of Societies for Ultrasound in Medicine and Biology (WFUMB-EFSUMB) venture in conjunction with other regional US societies such as Asian Federation of Societies for Ultrasound in Medicine and Biology, resulting in a simultaneous duplicate on liver CEUS in the official journals of both WFUMB and EFSUMB in 2013. However, no guidelines were described mainly for Sonazoid due to limited clinical experience only in Japan and Korea. The new proposed consensus statements and recommendations provide general advice on the use of Sonazoid and are intended to create standard protocols for the use and administration of Sonazoid in hepatic and pancreatobiliary applications in Asian patients and to improve patient management.

The AFSUMB Consensus Statements and Recommendations for the Clinical Practice of Contrast-Enhanced Ultrasound using Sonazoid

The first edition of the guidelines for the use of ultrasound contrast agents was published in 2004, dealing with liver applications. The second edition of the guidelines in 2008 reflected changes in the available contrast agents and updated the guidelines for the liver, as well as implementing some nonliver applications. The third edition of the contrast-enhanced ultrasound (CEUS) guidelines was the joint World Federation for Ultrasound in Medicine and Biology-European Federation of Societies for Ultrasound in Medicine and Biology (WFUMB-EFSUMB) venture in conjunction with other regional US societies such as Asian Federation of Societies for Ultrasound in Medicine and Biology, resulting in a simultaneous duplicate on liver CEUS in the official journals of both WFUMB and EFSUMB in 2013. However, no guidelines were described mainly for Sonazoid due to limited clinical experience only in Japan and Korea. The new proposed consensus statements and recommendations provide general advice on the use of Sonazoid and are intended to create standard protocols for the use and administration of Sonazoid in hepatic and pancreatobiliary applications in Asian patients and to improve patient management.

Current role of ultrasound in the diagnosis of hepatocellular carcinoma

Ultrasonography (US) is a major, sustainable hepatocellular carcinoma (HCC) surveillance method as it provides inexpensive, real-time, and noninvasive detection. Since US findings are based on pathological features, knowledge of pathological features is essential for delivering a correct US diagnosis. Recent advances in US equipment have made it possible to provide more information, such as malignancy potential and accurate localization diagnosis of HCC. Evaluation of malignancy potential is important to determine the treatment strategy, especially for small HCC. Diagnosis of blood flow dynamics using color Doppler and contrast-enhanced US is one of the most definitive approaches for evaluating HCC malignancy potential. Recently, a new Doppler microvascular imaging technique, superb microvascular imaging, which can detect Doppler signals generated by low-velocity blood flow, was developed. A fusion imaging system, another innovative US technology, has already become an indispensable technology over the last few years not only for US-guided radiofrequency ablation but also for the detection of small, invisible HCC. This article reviews the evidence on the use of ultrasound and contrast-enhanced ultrasound with Sonazoid for the practical management of HCC.

Application of new ultrasound techniques for focal liver lesions

Ultrasonography (US) has the overwhelming advantages of not entailing radiation exposure and being a noninvasive, real-time, convenient, easy-to-perform, and relatively inexpensive imaging modality. It is used as the first-line imaging modality for screening, detection, and diagnosis of focal liver lesions (FLLs) [small hepatocellular carcinomas (HCCs), in particular]. However, with the increasing demand for accurate and early diagnosis of small HCCs, newer radiologic methods need to be explored to overcome certain limitations of US. For example, the imaging is easily negatively affected by the presence of gas, rib cage, and subcutaneous fat, and is insensitive for capturing the subtle but vital information on the blood flow. It was in response to this need that new promising technologies such as contrast-enhanced ultrasound and fusion imaging were introduced for the detection of liver lesions. This paper presents an overview of the epidemiology and mechanisms of the development of HCCs, with an emphasis on the application of US in the diagnosis and treatment of FLLs. The aim of this article is to provide the state-of-the-art developments in the imaging diagnosis of FLLs and evaluation of ablation treatment of early HCCs. By keeping abreast of these recent advances, we hope that doctors and researchers working in the field of diagnosis/treatment of liver diseases will be able to discriminate benign FLLs such as regenerative nodules and focal nodular hyperplasia from HCCs, so as to avoid unnecessary repeated tumor biopsies and overtreatment. In particular, we expect that small HCCs or precancerous nodules (such as dysplastic nodules) can be accurately diagnosed and appropriately treated even at an early stage.

Comparison Between Low Mechanical Index and High Mechanical Index Contrast Modes of Contrast-Enhanced Ultrasonography: Evaluation of Perfusion Defects of Hypervascular Hepatocellular Carcinomas During the Post-Vascular Phase

OBJECTIVES

We evaluated the detection rates for perfusion defects in hypervascular hepatocellular carcinomas comparing the low mechanical index (MI) and high MI contrast modes during the post-vascular phase (PVP) of contrast-enhanced ultrasonography.

METHODS

Seventy-eight patients with 84 hypervascular hepatocellular carcinomas (mean diameter, 23.4 ± 11.2 mm) were selected for this retrospective study. All the patients underwent whole-liver scanning using conventional ultrasonography before injection of a perflubutane-based contrast agent (Sonazoid), and all the detected nodules were classified as either hypoechoic or hyperechoic nodules. Next, hypoechoic and hyperechoic nodules were evaluated using contrast-enhanced ultrasonography, and the presence of a perfusion defect was assessed for each nodule using both the low MI (0.2-0.3) and the high MI (0.7-1.2) contrast modes during the PVP (10 minutes after injection). The data were analyzed using the McNemar test.

RESULTS

Forty-four nodules were classified as hypoechoic nodules, and the remaining 40 nodules were classified as hyperechoic nodules using conventional ultrasonography. The detection rate for perfusion defects determined using the high MI contrast mode was higher than that determined using the low MI contrast mode in hyperechoic nodules during the PVP (low MI, 58% [23 of 40]; high MI, 90% [36 of 40]; P < .0001). However, no significant difference was observed between the low MI and the high MI contrast modes in hypoechoic nodules (low MI, 80% [35 of 44]; high MI, 89% [39 of 44]; P = .125).

CONCLUSION

Compared with the low MI contrast mode, the high MI contrast mode was more sensitive for detecting perfusion defects in hypervascular hepatocellular carcinomas in patients with hyperechoic nodules during the PVP.

Fusion imaging with contrast-enhanced ultrasonography for evaluating the early therapeutic efficacy of radiofrequency ablation for small hypervascular hepatocellular carcinomas with iso-echoic or unclear margins on conventional ultrasonography

PURPOSE

We evaluated the efficacy of fusion imaging combining contrast-enhanced ultrasonography (CEUS) images and arterial phase contrast-enhanced CT (CECT) or hepatobiliary phase magnetic resonance imaging with gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (EOB-MRI) images for the early evaluation of the effectiveness of radiofrequency ablation (RFA) for small hypervascular hepatocellular carcinoma (HCC) with iso-echoic or unclear margins on conventional US.

METHODS

Forty HCCs (22 iso-echoic and 18 unclear margin lesions) with mean diameters of 13.7 mm were treated using RFA under the guidance of fusion imaging with CEUS. The adequacy of RFA was evaluated using fusion imaging with CEUS 1 day after RFA. CECT or EOB-MRI was performed 1 month after RFA. We reviewed the images obtained using both modalities.

RESULTS

When the 1-month CECT or EOB-MRI scans were used as the reference standard, the sensitivity, specificity, and accuracy of the 1-day fusion imaging for the diagnosis of the adequate ablation of these HCCs were 97, 100, and 98%, respectively; the kappa value for the agreement between the findings using the two modalities was 0.655.

CONCLUSION

Fusion imaging with CEUS appears to be a useful method for the early evaluation of the efficacy of RFA for the treatment of HCCs with iso-echoic or unclear margins on conventional US.

Rate of local tumor progression following radiofrequency ablation of pathologically early hepatocellular carcinoma

AIM

To evaluate whether pathologically early hepatocellular carcinoma (HCC) exhibited local tumor progression after radiofrequency ablation (RFA) less often than typical HCC.

METHODS

Fifty pathologically early HCCs [tumor diameter (mm): mean, 15.8; range, 10-23; follow-up days after RFA: median, 1213; range, 216-2137] and 187 typical HCCs [tumor diameter (mm): mean, 15.6; range, 6-30; follow-up days after RFA: median, 1116; range, 190-2328] were enrolled in this retrospective study. The presence of stromal invasion (namely, tumor cell invasion into the intratumoral portal tracts) was considered to be the most important pathologic finding for the diagnosis of early HCCs. Typical HCC was defined as the presence of a hyper-vascular lesion accompanied by delayed washout using contrast-enhanced computed tomography or contrast-enhanced magnetic resonance imaging. Follow-up examinations were performed at 3-mo intervals to monitor for signs of local tumor progression. The local tumor progression rates of pathologically early HCCs and typical HCCs were then determined using the Kaplan-Meier method.

RESULTS

During the follow-up period for the 50 pathologically early HCCs, 49 (98%) of the nodules did not exhibit local tumor progression. However, 1 nodule (2%) was associated with a local tumor progression found 636 d after RFA. For the 187 typical HCCs, 46 (24.6%) of the nodules exhibited local recurrence after RFA. The follow-up period until the local tumor progression of typical HCC was a median of 605 d, ranging from 181 to 1741 d. Among the cases with typical HCCs, local tumor progression had occurred in 7.0% (7/187), 16.0% (30/187), 21.9% (41/187) and 24.6% (46/187) of the cases at 1, 2, 3 and 4 years, respectively. Pathologically early HCC was statistically associated with a lower rate of local tumor progression, compared with typical HCC, when evaluated using a log-rank test (P = 0.002).

CONCLUSION

The rate of local tumor progression for pathologically early HCCs after RFA was significantly lower than that for typical HCCs.

Evaluation of hepatocellular carcinoma tumor vascularity using contrast-enhanced ultrasonography as a predictor for local recurrence following radiofrequency ablation

PURPOSE

The purpose of this study was to evaluate whether the hypervascularity of hepatocellular carcinomas (HCCs) on contrast-enhanced ultrasonography (CEUS) prior to radiofrequency ablation (RFA) is a significant risk factor for local recurrence after RFA.

MATERIALS AND METHODS

Institutional review board approval and informed consent were obtained. Overall, 208 patients (mean age, 71.7 years; range, 50-87 years; 137 men, 71 women) with 282 HCCs treated with RFA were analyzed retrospectively. The mean maximum tumor diameter was 15.7mm. We compared the abilities of CEUS and contrast-enhanced computed tomography (CECT) to detect hypervascularity in HCCs. We then classified the HCCs into two groups according to the arterial-phase CEUS findings: a "hypervascular group" with whole or partial hypervascular areas within the lesions compared with the surrounding liver parenchyma, and a "non-hypervascular group" with isovascular or hypovascular areas within the lesions. We assessed the cumulative rate of local recurrence after RFA, and we also evaluated the risk factors for local recurrence using a univariate analysis.

RESULTS

The detection rate for hypervascular HCCs was significantly higher using CEUS (78%, 221/282) than that using CECT (66%, 186/282) (P<0.001). Using the CEUS findings, the cumulative rate of local recurrence was significantly higher in the hypervascular group (41.2%, 56/221) than in the non-hypervascular group (18.4%, 6/61) (P=0.007). A univariate analysis revealed that hypervascularity on CEUS was an independent risk factor for local recurrence (P=0.010).

CONCLUSION

Hypervascularity in HCCs as observed using CEUS is a significant risk factor for local recurrence after RFA.

Central vascular structures as a characteristic finding of regenerative nodules using hepatobiliary phase gadolinium ethoxybenzyl diethylenetriaminepentaacetic acid-enhanced MRI and arterial dominant phase contrast-enhanced US

OBJECTIVE

We investigated the characteristic findings of regenerative nodules (RNs) for differentiating early hepatocellular carcinoma (HCC) from high-grade dysplastic nodules (HGDNs) using magnetic resonance imaging (MRI) with gadolinium ethoxybenzyl diethylenetriaminepentaacetic acid (Gd-EOB-DTPA; EOB-MRI) and contrast-enhanced ultrasonography (CEUS) in patients with chronic liver disease.

SUBJECTS AND METHODS

Pathologically confirmed lesions (100 early HCCs, 7 HGDNs, and 20 RNs with a maximum diameter of more than 1 cm and mean maximal diameters of 15.5, 15.1, and 14.8 mm, respectively) were enrolled in this retrospective study. The signal intensities of these lesions during the hepatobiliary phase of EOB-MRI were investigated, and findings characteristic of RNs using this modality were also evaluated using CEUS.

RESULTS

Ninety-eight of the 100 early HCCs that were hypo-intense (n = 95), iso-intense (n = 2), or hyper-intense (n = 1) and the seven HGDNs that were hypo-intense (n = 6) or hyper-intense (n = 1) during the hepatobiliary phase of EOB-MRI exhibited centripetal vessels during the arterial dominant phase of CEUS, although one early HCC that was hypo-intense exhibited both centrifugal and centripetal vessels. Eighteen of the 20 RNs and one early HCC that were hyper-intense with a small central hypo-intensity and the remaining two RNs that were hyper-intense on EOB-MRI exhibited centrifugal vessels during the arterial dominant phase of CEUS. The small central hypo-intense area corresponded to central vascular structures in the lesion, such as the hepatic artery and portal vein running from the center to the periphery, when viewed using CEUS.

CONCLUSION

Central vascular structures may be a characteristic finding of RNs when observed during the hepatobiliary phase of EOB-MRI and the arterial dominant phase of CEUS.

Use of vessel patterns on contrast-enhanced ultrasonography using a perflubutane-based contrast agent for the differential diagnosis of regenerative nodules from early hepatocellular carcinoma or high-grade dysplastic nodules in patients with chronic liver disease

OBJECTIVE

We evaluated the use of tumor vessel patterns observed during arterial-phase contrast-enhanced ultrasonography (US) to differentiate regenerative nodules (RN) from early hepatocellular carcinoma (HCC) or high-grade dysplastic nodules (HGDN) in patients with chronic liver disease.

SUBJECTS AND METHODS

Pathologically confirmed lesions (83 early HCC, 6 HGDN, and 13 RN with mean maximal diameters of 15.4, 15.3, and 16.2 mm, respectively) were enrolled in this retrospective study. We performed contrast-enhanced US using a perflubutane-based contrast agent. We then classified the tumor vessels observed during the arterial phase of contrast-enhanced US into two patterns: peripheral vessels (centripetal pattern) and central vessels (centrifugal pattern).

RESULTS

Eighty-one (97.6%) of the 83 early HCC exhibited various enhancement patterns (hypovascular, 44.6%; isovascular, 25.3%; and hypervascular, 27.7%) and a peripheral vessel pattern, while the remaining 2 lesions (2.4%) exhibited hypovascular enhancement and a central vessel pattern. All 6 HGDN lesions were hypovascular with a peripheral vessel pattern. Twelve (92.3%) of the 13 RN were hypovascular with a central vessel pattern, and the remaining one (7.7%) was hypervascular with a central vessel pattern. When lesions exhibiting a central vessel pattern during arterial-phase contrast-enhanced US were diagnosed as RN, the sensitivity, specificity, and accuracy of these diagnoses were 100%, 97.8%, and 98.0%, respectively.

CONCLUSION

The tumor vessel patterns observed during arterial-phase contrast-enhanced US may be useful for differentiating RN from early HCC or HGDN in patients with chronic liver disease.

Role of contrast-enhanced ultrasonography with Sonazoid for hepatocellular carcinoma: evidence from a 10-year experience

Hepatocellular carcinoma (HCC) represents primary liver cancer. Because the development of HCC limits the prognosis as well as the quality of life of the patients, its management should be properly conducted based on an accurate diagnosis. The liver is the major target organ of ultrasound (US), which is the simple, non-invasive, and real-time imaging method available worldwide. Microbubble-based contrast agents are safe and reliable and have become popular, which has resulted in the improvement of diagnostic performances of US due to the increased detectability of the peripheral blood flow. Sonazoid (GE Healthcare, Waukesha, WI, USA), a second-generation contrast agent, shows the unique property of accumulation in the liver and spleen. Contrast-enhanced US with Sonazoid is now one of the most frequently used modalities in the practical management of liver tumors, including the detection and characterization of the nodule, evaluation of the effects of non-surgical treatment, intraoperative support, and post-treatment surveillance. This article reviews the 10-year evidence for contrast-enhanced US with Sonazoid in the practical management of HCC.

Local ablation therapy with contrast-enhanced ultrasonography for hepatocellular carcinoma: a practical review

A successful program for local ablation therapy for hepatocellular carcinoma (HCC) requires extensive imaging support for diagnosis and localization of HCC, imaging guidance for the ablation procedures, and post-treatment monitoring. Contrast-enhanced ultrasonography (CEUS) has several advantages over computed tomography/magnetic resonance imaging (CT/MRI), including real-time imaging capability, sensitive detection of arterial-phase hypervascularity and washout, no renal excretion, no ionizing radiation, repeatability, excellent patient compliance, and relatively low cost. CEUS is useful for image guidance for isoechoic lesions. While contrast-enhanced CT/MRI is the standard method for the diagnosis of HCC and post-ablation monitoring, CEUS is useful when CT/MRI findings are indeterminate or CT/MRI is contraindicated. This article provides a practical review of the role of CEUS in imaging algorithms for pre- and post-ablation therapy for HCC.

Imaging Techniques for the Diagnosis of Hepatocellular Carcinoma: A Systematic Review and Meta-analysis

BACKGROUND

Several imaging modalities are available for diagnosis of hepatocellular carcinoma (HCC).

PURPOSE

To evaluate the test performance of imaging modalities for HCC.

DATA SOURCES

MEDLINE (1998 to December 2014), the Cochrane Library Database, Scopus, and reference lists.

STUDY SELECTION

Studies on test performance of ultrasonography, computed tomography (CT), or magnetic resonance imaging (MRI).

DATA EXTRACTION

One investigator abstracted data, and a second investigator confirmed them; 2 investigators independently assessed study quality and strength of evidence.

DATA SYNTHESIS

Few studies have evaluated imaging for HCC in surveillance settings. In nonsurveillance settings, sensitivity for detection of HCC lesions was lower for ultrasonography without contrast than for CT or MRI (pooled difference based on direct comparisons, 0.11 to 0.22), and MRI was associated with higher sensitivity than CT (pooled difference, 0.09 [95% CI, 0.07 to 12]). For evaluation of focal liver lesions, there were no clear differences in sensitivity among ultrasonography with contrast, CT, and MRI. Specificity was generally 0.85 or higher across imaging modalities, but this item was not reported in many studies. Factors associated with lower sensitivity included use of an explanted liver reference standard, and smaller or more well-differentiated HCC lesions. For MRI, sensitivity was slightly higher for hepatic-specific than nonspecific contrast agents.

LIMITATIONS

Only English-language articles were included, there was statistical heterogeneity in pooled analyses, and costs were not assessed. Most studies were conducted in Asia and had methodological limitations.

CONCLUSION

CT and MRI are associated with higher sensitivity than ultrasonography without contrast for detection of HCC; sensitivity was higher for MRI than CT. For evaluation of focal liver lesions, the sensitivities of ultrasonography with contrast, CT, and MRI for HCC are similar.

PRIMARY FUNDING SOURCE

Agency for Healthcare Research and Quality. (

PROSPERO

CRD42014007016).

Imagiological Diagnosis of Gastrointestinal Diseases - Diagnostic Criteria of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the leading causes of neoplastic morbidity and mortality worldwide, and despite recent treatment advances, the prognosis remains dismal, with a 5-year mortality rate of 85%.

The surveillance and timely diagnosis is therefore of crucial importance in order to improve survival rates and alleviate the health burden imposed by the HCC.

Previously, HCC diagnosis warranted liver biopsy, an invasive process with limited diagnostic accuracy. In the past 15 years, HCC diagnosis based solely on imaging criteria was accepted by all the major national and international guidelines, and is now widely employed across the globe.

Current European guidelines for the HCC diagnosis support the use of both dynamic contrasted computer tomography as well as magnetic resonance imaging for the non-invasive diagnosis of HCC for nodules >1 cm in a cirrhotic liver. The non-invasive diagnosis of HCC depends on radiological hallmarks, such as homogeneous contrast uptake during the arterial phase and wash-out during the venous and late phases, but while such tumoral behaviour is frequent in nodules >2 cm, high-end equipment and superior expertise is often needed for the correct diagnosis of early HCC.

Nevertheless, the accuracy of imaging techniques for the diagnosis of HCC is permanently improving, and supports the progressively reduced need for liver biopsy during liver nodule workout in a cirrhotic liver.

Tumor Markers for Hepatocellular Carcinoma: Simple and Significant Predictors of Outcome in Patients with HCC

BACKGROUND

The effectiveness of tumor markers in evaluating outcomes of patients with hepatocellular carcinoma (HCC) remains to be clarified.

SUMMARY

The usefulness of the HCC tumor markers, alpha-fetoprotein (AFP), Lens culinaris agglutinin-reactive fraction of alpha-fetoprotein (AFP-L3), and des-gamma-carboxy prothrombin (DCP) was reviewed. Elevations in these tumor markers at the time of HCC diagnosis correlate with disease progression as assessed by both imaging studies and pathologic examinations. The combination of these three tumor markers results in good predictive ability for patient survival after diagnosis. In addition, combination at the time of HCC diagnosis of these three tumor markers (as a measure of tumor progression) and serum albumin and bilirubin levels (as indicators of remnant liver function) can be used for HCC staging and further predicts prognosis in patients with HCC.

KEY MESSAGE

The prognosis of patients with HCC can be well discriminated based solely on serum markers. Staging of HCC with serum markers is objective; if stored serum samples are available, HCC stages can be standardized across different countries and time periods.