Hepatic malignancies: Correlation between sonographic findings and pathological features

Hyperechogenicity and histopathological features of focal liver lesions

The identification and accurate diagnosis of focal liver lesions are important in modern medicine, where diagnostic radiology plays an essential role. This review aimed to examine the hyperechogenicity and histopathological features of focal liver lesions. Hyperechogenic liver lesions can be either benign or malignant. Evidence shows that hyperechogenicity is caused by factors such as fat deposition, sinusoidal dilation, peliotic changes, and pseudoglandular patterns. Fat deposition is a common cause of increased echogenicity in hepatocellular carcinoma (HCC). Meanwhile, sinusoidal dilation and peliotic changes are more frequently observed in larger HCC nodules. Pseudoglandular patterns, characterized by the reflection of ultrasound waves at the walls of numerous acini, are associated with hyperechogenicity in well-to-moderately differentiated HCCs. Moreover, this review comprehensively examined the histological features that may cause hyperechogenic internal echoes in not only HCCs but also localized liver lesions (metastases of adenocarcinoma and neuroendocrine neoplasm, intrahepatic cholangiocarcinoma, cavernous hemangioma, focal nodular hyperplasia, and angiomyolipoma). To make an accurate diagnosis and provide appropriate management, it is important to understand the histopathological basis for hyperechogenicity in focal liver lesions. By maximizing the accuracy of imaging studies and enhancing the radiology-pathology correlation, unnecessary biopsies can be avoided, thereby reducing potential complications and mortality. This review can help facilitate the effective management of patients with focal liver lesions, thereby resulting in timely and appropriate treatment decision-making.

From biology to the clinic - exploring liver metastasis in prostate cancer

Liver metastases from prostate cancer are associated with an aggressive disease course and poor prognosis. Results from autopsy studies indicate a liver metastasis prevalence of up to 25% in patients with advanced prostate cancer. Population data estimate that ~3-10% of patients with metastatic castration-resistant prostate cancer harbour liver metastases at the baseline, rising to 20-30% in post-treatment cohorts, suggesting that selective pressure imposed by novel therapies might promote metastatic spread to the liver. Liver metastases are associated with more aggressive tumour biology than lung metastases. Molecular profiling of liver lesions showed an enrichment of low androgen receptor, neuroendocrine phenotypes and high genomic instability. Despite advancements in molecular imaging modalities such as prostate-specific membrane antigen PET-CT, and liquid biopsy markers such as circulating tumour DNA, early detection of liver metastases from prostate cancer remains challenging, as both approaches are hampered by false positive and false negative results, impeding the accurate identification of early liver lesions. Current therapeutic strategies showed limited efficacy in this patient population. Emerging targeted radionuclide therapies, metastasis-directed therapy, and novel systemic agents have shown preliminary activity against liver metastases, but require further validation. Treatment with various novel prostate cancer therapies might lead to an increase in the prevalence of liver metastasis, underscoring the urgent need for coordinated efforts across preclinical and clinical researchers to improve characterization, monitoring, and management of liver metastases from prostate cancer. Elucidating molecular drivers of liver tropism and interactions with the liver microenvironment might ultimately help to identify actionable targets to enhance survival in this high-risk patient group.

Point-of-care ultrasound to inform antiviral treatment initiation in chronic hepatitis B virus infection in low-resource settings - the PUSH protocol

BACKGROUND

Chronic Hepatitis B (CHB) is prevalent worldwide and most related deaths occur in low-resource settings. Antiviral treatment of CHB is indicated in those with significant liver disease and markers of viral replication. However, recommended diagnostics such as elastography (a non-invasive imaging measure of fibrosis/cirrhosis) or HBV viral load are often lacking in these settings, which creates barriers to treatment. Point-of-care clinical B-mode ultrasound (US) has potential to overcome implementation barriers in HBV care programs in low-resource settings.

METHODS

We describe a Point-of-care US protocol for Hepatitis ("PUSH") to check for signs of cirrhosis and hepatocellular carcinoma in the liver of people with CHB. We performed a prospective observational study applying the protocol, first by trainee clinicians and then by trainers, in consecutive patients referred to our clinic for CHB treatment eligibility assessment. All patients additionally underwent physical examination, liver function tests (LFTs) and platelet counts. We describe the PUSH training approach and performance of the protocol.

RESULTS

Four clinicians and 111 adult patients with HBV infection were included in the development of PUSH. Using US, liver complications of HBV were documented in 31 (27.9%) patients; including cirrhosis in 15 patients, HCC with cirrhosis in 13, and HCC without cirrhosis in 3. Patients with sonographic findings had significantly more clinical symptoms also their LFTs were higher and more frequently indicative for HBV treatment. Of 28 patients with sonographic diagnosis of cirrhosis, 23 (82.1%) showed a nodular liver surface, 24 (85.7%) a coarse echotexture, 20 (71.4%) scarce vessels, and 9 (32.1%) an enlarged caudate lobe. Overall concordance of the findings between assessment of trainees and experienced sonographers was high, ranging from 90 to 95%; trainees were not blinded to clinical and laboratory findings.

CONCLUSION

Ultrasound can facilitate same-day initiation of antiviral therapy for chronic HBV monoinfection in a resource-limited setting and a streamlined protocol-driven liver ultrasound can be feasibly used by front line clinicians managing HBV.

Development and Comparison of Prediction Models Based on Sonovue- and Sonazoid-Enhanced Ultrasound for Pathologic Grade and Microvascular Invasion in Hepatocellular Carcinoma

OBJECTIVE

This study was aimed at developing and comparing prediction models based on Sonovue and Sonazoid contrast-enhanced ultrasound (CEUS) in predicting pathologic grade and microvascular invasion (MVI) of hepatocellular carcinoma (HCC). Also investigated was whether Kupffer phase images have additional predictive value for the above pathologic features.

METHODS

Ninety patients diagnosed with primary HCC who had undergone curative hepatectomy were prospectively enrolled. All patients underwent conventional ultrasound (CUS), Sonovue-CEUS and Sonazoid-CEUS examinations pre-operatively. Clinical, radiologic and pathologic features including pathologic grade, MVI and CD68 expression were collected. We developed prediction models comprising clinical, CUS and CEUS (Sonovue and Sonazoid, respectively) features for pathologic grade and MVI with both the logistic regression and machine learning (ML) methods.

RESULTS

Forty-one patients (45.6%) had poorly differentiated HCC (p-HCC) and 37 (41.1%) were MVI positive. For pathologic grade, the logistic model based on Sonazoid-CEUS had significantly better performance than that based on Sonovue-CEUS (area under the curve [AUC], 0.929 vs. 0.848, p = 0.035), whereas for MVI, these two models had similar accuracy (AUC, 0.810 vs. 0.786, p = 0.068). Meanwhile, we found that well-differentiated HCC tended to have a higher enhancement ratio in 6-12 min during the Kupffer phase of Sonazoid-CEUS, as well as higher CD68 expression compared with p-HCC. In addition, all of these models can effectively predict the risk of recurrence (p < 0.05).

CONCLUSION

Sonovue-CEUS and Sonazoid-CEUS were comparably excellent in predicting MVI, while Sonazoid-CEUS was superior to Sonovue-CEUS in predicting pathologic grade because of the Kupffer phase. The enhancement ratio in the Kupffer phase has additional predictive value for pathologic grade prediction.

The Clinical Value of Multimodal Ultrasound for the Differential Diagnosis of Hepatocellular Carcinoma from Other Liver Tumors in Relation to Histopathology

Recent advances in the field of ultrasonography offer promising tools for the evaluation of liver tumors. We aim to assess the value of multimodal ultrasound in differentiating hepatocellular carcinomas (HCCs) from other liver lesions. We prospectively included 66 patients with 72 liver tumors. The histological analysis was the reference standard for the diagnosis of malignant liver lesions, and partially for benign tumors. All liver lesions were assessed by multiparametric ultrasound: standard ultrasound, contrast-enhanced ultrasound (CEUS), the point shear wave elastography (pSWE) using shear wave measurement (SWM) method and real-time tissue elastography (RTE). To diagnose HCCs, CEUS achieved a sensitivity, specificity, accuracy and positive predictive value (PPV) of 69.05%, 92.86%, 78.57% and 93.55%, respectively. The mean shear-wave velocity (Vs) value in HCCs was 1.59 ± 0.29 m/s, which was lower than non-HCC malignancies (p < 0.05). Using a cut-off value of 1.58 m/s, SWM achieved a sensitivity of 54.76%, and 82.35% specificity, for differentiating HCCs from other malignant lesions. The combination of SWM and CEUS showed higher sensitivity (79.55%) compared with each technique alone, while maintaining a high specificity (89.29%). In RTE, most HCCs (61.53%) had a mosaic pattern with dominant blue areas corresponding to type "c" elasticity. Elasticity type "c" was 70.59% predictive for HCCs. In conclusion, combining B-mode ultrasound, CEUS, pSWE and RTE can provide complementary diagnostic information and potentially decrease the requirements for other imaging modalities.

[Ultrasound diagnostics of the liver : Principles and important pathologies]

Diffuse changes in the liver parenchyma, focal lesions and blood flow in hepatic vessels can be assessed using ultrasound. Screening by ultrasound can be used to detect hepatocellular carcinomas as possible malignant sequelae of liver cirrhosis. As metastases are far more frequent than primary malignant liver tumors, secondary malignant neoplasms should be taken into consideration as a differential diagnosis in the presence of focal liver lesions. This particularly concerns patients with a known metastatic disease. Benign focal liver lesions are often incidentally discovered in women of childbearing age. Cysts, hemangiomas and focal nodular hyperplasia mostly show typical morphological features in ultrasound and do not require further follow-up; however, with hepatic adenomas, regular follow-up is recommended due to the risk of bleeding and/or malignant transformation.

Imaging Diagnosis of Hepatocellular Carcinoma: A State-of-the-Art Review

Hepatocellular carcinoma (HCC) remains not only a cause of a considerable part of oncologic mortality, but also a diagnostic and therapeutic challenge for healthcare systems worldwide. Early detection of the disease and consequential adequate therapy are imperative to increase patients' quality of life and survival. Imaging plays, therefore, a crucial role in the surveillance of patients at risk, the detection and diagnosis of HCC nodules, as well as in the follow-up post-treatment. The unique imaging characteristics of HCC lesions, deriving mainly from the assessment of their vascularity on contrast-enhanced computed tomography (CT), magnetic resonance (MR) or contrast-enhanced ultrasound (CEUS), allow for a more accurate, noninvasive diagnosis and staging. The role of imaging in the management of HCC has further expanded beyond the plain confirmation of a suspected diagnosis due to the introduction of ultrasound and hepatobiliary MRI contrast agents, which allow for the detection of hepatocarcinogenesis even at an early stage. Moreover, the recent technological advancements in artificial intelligence (AI) in radiology contribute an important tool for the diagnostic prediction, prognosis and evaluation of treatment response in the clinical course of the disease. This review presents current imaging modalities and their central role in the management of patients at risk and with HCC.

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.

Rabbit VX2 Liver Tumor Model: A Review of Clinical, Biology, Histology, and Tumor Microenvironment Characteristics

The rabbit VX2 is a large animal model of cancer used for decades by interventional radiologists to demonstrate the efficacy of various locoregional treatments against liver tumors. What do we know about this tumor in the new era of targeted therapy and immune-oncology? The present paper describes the current knowledge on the clinics, biology, histopathology, and tumor microenvironment of VX2 based on a literature review of 741 publications in the liver and in other organs. It reveals the resemblance with human cancer (anatomy, vascularity, angiogenic profile, drug sensitivity, immune microenvironment), the differences (etiology, growth rate, histology), and the questions still poorly explored (serum and tissue biomarkers, genomic alterations, immune checkpoint inhibitors efficacy).

Contrast-Enhanced Ultrasound for Differentiation Between Poorly Differentiated Hepatocellular Carcinoma and Intrahepatic Cholangiocarcinoma

PURPOSE

To evaluate the diagnostic performance of LR-5 for diagnosing poorly differentiated hepatocellular carcinoma (p-HCC). To build a contrast-enhanced ultrasound (CEUS) signature for improving the differential diagnostic performance between p-HCC and intrahepatic cholangiocarcinoma (ICC).

METHODS

The B-mode ultrasound (BUS) and CEUS features of 60 p-HCCs and 56 ICCs were retrospectively analyzed. The CEUS LI-RADS category was assigned according to CEUS LI-RADS v2017. A diagnostic CEUS signature was built based on the independent significant features. An ultrasound (US) signature combining both BUS and CEUS features was also built. The diagnostic performances of the CEUS signature, US signature, and LR-5 were evaluated by receiver operating characteristic (ROC) analysis.

RESULTS

One (1.7%) p-HCC and 26 (46.4%) ICC patients presented cholangiectasis or cholangiolithiasis (P < .001). Fifty-four (90.0%) p-HCCs and 8 (14.3%) ICCs showed clear boundaries in the artery phase (P < .001). The washout times of p-HCCs and ICCs were 81.0 ± 42.5 s and 34.7 ± 8.6 s, respectively (P < .001). The AUC, sensitivity, and specificity of the CEUS signature, US signature, and LR-5 were 0.955, 91.67%, and 90.57% versus 0.976, 96.67%, and 92.45% versus 0.758, 51.67%, and 100%, respectively. The AUC and sensitivity of CEUS LI-RADS were much lower than those of the CEUS and US signatures (P < .001).

CONCLUSION

LR-5 had high specificity but low sensitivity in diagnosing p-HCC. When the washout time and tumor boundary were included in the CEUS signature, the sensitivity and AUC were remarkably increased in the differentiation between p-HCC and ICC.

Liver metastases

Liver metastases are commonly detected in a range of malignancies including colorectal cancer (CRC), pancreatic cancer, melanoma, lung cancer and breast cancer, although CRC is the most common primary cancer that metastasizes to the liver. Interactions between tumour cells and the tumour microenvironment play an important part in the engraftment, survival and progression of the metastases. Various cells including liver sinusoidal endothelial cells, Kupffer cells, hepatic stellate cells, parenchymal hepatocytes, dendritic cells, resident natural killer cells as well as other immune cells such as monocytes, macrophages and neutrophils are implicated in promoting and sustaining metastases in the liver. Four key phases (microvascular, pre-angiogenic, angiogenic and growth phases) have been identified in the process of liver metastasis. Imaging modalities such as ultrasonography, CT, MRI and PET scans are typically used for the diagnosis of liver metastases. Surgical resection remains the main potentially curative treatment among patients with resectable liver metastases. The role of liver transplantation in the management of liver metastasis remains controversial. Systemic therapies, newer biologic agents (for example, bevacizumab and cetuximab) and immunotherapeutic agents have revolutionized the treatment options for liver metastases. Moving forward, incorporation of genetic tests can provide more accurate information to guide clinical decision-making and predict prognosis among patients with liver metastases.

Performance of Ultrasound Techniques and the Potential of Artificial Intelligence in the Evaluation of Hepatocellular Carcinoma and Non-Alcoholic Fatty Liver Disease

Global statistics show an increasing percentage of patients that develop non-alcoholic fatty liver disease (NAFLD) and NAFLD-related hepatocellular carcinoma (HCC), even in the absence of cirrhosis. In the present review, we analyzed the diagnostic performance of ultrasonography (US) in the non-invasive evaluation of NAFLD and NAFLD-related HCC, as well as possibilities of optimizing US diagnosis with the help of artificial intelligence (AI) assistance. To date, US is the first-line examination recommended in the screening of patients with clinical suspicion of NAFLD, as it is readily available and leads to a better disease-specific surveillance. However, the conventional US presents limitations that significantly hamper its applicability in quantifying NAFLD and accurately characterizing a given focal liver lesion (FLL). Ultrasound contrast agents (UCAs) are an essential add-on to the conventional B-mode US and to the Doppler US that further empower this method, allowing the evaluation of the enhancement properties and the vascular architecture of FLLs, in comparison to the background parenchyma. The current paper also explores the new universe of AI and the various implications of deep learning algorithms in the evaluation of NAFLD and NAFLD-related HCC through US methods, concluding that it could potentially be a game changer for patient care.

Direct comparison of biopsy techniques for hepatic malignancies

Background/Aims

The core needle biopsy (CNB), fine needle aspiration cytology (FNAC) and touch imprint cytology (TIC) are commonly used tools for the diagnosis of hepatic malignancies. However, little is known about the benefits and criteria for selecting appropriate technique among them in clinical practice. We aimed to compare the sensitivity of ultrasound-guided CNB, FNAC, TIC as well as combinations for the diagnosis of hepatic malignancies, and to determine the factors associated with better sensitivity in each technique.

Methods

From January 2018 to December 2019, a total of 634 consecutive patients who received ultrasound-guided liver biopsies at the National Taiwan University Hospital was collected, of whom 235 with confirmed malignant hepatic lesions receiving CNB, FNAC and TIC simultaneously were enrolled for analysis. The clinical and procedural data were compared.

Results

The sensitivity of CNB, FNAC and TIC for the diagnosis of malignant hepatic lesions were 93.6%, 71.9%, and 85.1%, respectively. Add-on use of FNAC or TIC to CNB provided additional sensitivity of 2.1% and 0.4%, respectively. FNAC exhibited a significantly higher diagnostic rate in the metastatic cancers (P=0.011), hyperechoic lesions on ultrasound (P=0.028), and those with depth less than 4.5 cm from the site of needle insertion (P=0.036).

Conclusions

The sensitivity of CNB is superior to that of FNAC and TIC for the diagnosis of hepatic malignancies. Nevertheless, for shallow (depth <4.5 cm) and hyperechoic lesions not typical for primary liver cancers, FNAC alone provides excellent sensitivity.

Trefoil Factor Family 1 Inhibits the Development of Hepatocellular Carcinoma by Regulating β-Catenin Activation

BACKGROUND AND AIMS

Recent studies have suggested that trefoil factor family 1 (TFF1) functions as a tumor suppressor in gastric and pancreatic carcinogenesis.

APPROACH AND RESULTS

To investigate the role of TFF1 in hepatocarcinogenesis, we performed immunohistochemical staining of surgically resected human liver samples, transfected a TFF1 expression vector into hepatocellular carcinoma (HCC) cell lines, and employed a mouse model of spontaneous HCC development (albumin-cyclization recombination/Lox-Stop-Lox sequence-Kirsten rat sarcoma viral oncogene homolog^G12D [KC]); the model mouse strain was bred with a TFF1-knockout mouse strain to generate a TFF1-deficient HCC mouse model (KC/TFF1^-/- ). TFF1 expression was found in some human samples with HCC. Interestingly, TFF1-positive cancer cells showed a staining pattern contradictory to that of proliferating cell nuclear antigen, and aberrant DNA hypermethylation in TFF1 promoter lesions was detected in HCC samples, indicating the tumor-suppressive role of TFF1. In vitro, induction of TFF1 expression resulted in impaired proliferative activity and enhanced apoptosis in HCC cell lines (HuH7, HepG2, and HLE). These anticancer effects of TFF1 were accompanied by the loss of nuclear β-catenin expression, indicating inactivation of the β-catenin signaling pathway by TFF1. In vivo, TFF1 deficiency in KC mice accelerated the early development and growth of HCC, resulting in poor survival rates. In addition, immunohistochemistry revealed that the amount of nuclear-localized β-catenin was significantly higher in KC/TFF1^-/- mice than in KC mice and that human HCC tissue showed contradictory expression patterns for β-catenin and TFF1, confirming the in vitro observations.

CONCLUSIONS

TFF1 might function as a tumor suppressor that inhibits the development of HCC by regulating β-catenin activity.

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.

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.

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.

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.

A Pathway to Personalizing Therapy for Metastases Using Liver-on-a-Chip Platforms

Metastasis accounts for most cancer-related deaths. The majority of solid cancers, including those of the breast, colorectum, prostate and skin, metastasize at significant levels to the liver due to its hemodynamic as well as tumor permissive microenvironmental properties. As this occurs prior to detection and treatment of the primary tumor, we need to target liver metastases to improve patients' outcomes. Animal models, while proven to be useful in mechanistic studies, do not represent the heterogeneity of human population especially in drug metabolism lack proper human cell-cell interactions, and this gap between animals and humans results in costly and inefficient drug discovery. This underscores the need to accurately model the human liver for disease studies and drug development. Further, the occurrence of liver metastases is influenced by the primary tumor type, sex and race; thus, modeling these specific settings will facilitate the development of personalized/targeted medicine for each specific group. We have adapted such all-human 3D ex vivo hepatic microphysiological system (MPS) (a.k.a. liver-on-a-chip) to investigate human micrometastases. This review focuses on the sources of liver resident cells, especially the iPS cell-derived hepatocytes, and examines some of the advantages and disadvantages of these sources. In addition, this review also examines other potential challenges and limitations in modeling human liver.

A lexicon for hepatocellular carcinoma surveillance ultrasonography: benign versus malignant lesions

BACKGROUND/AIMS

To suggest a lexicon for liver ultrasonography and to identify radiologic features indicative of benign or malignant lesions on surveillance ultrasonography.

METHODS

This retrospective study included 188 nodules (benign, 101; malignant, 87) from 175 at-risk patients identified during surveillance ultrasonography for hepatocellular carcinoma. We created a lexicon for liver ultrasonography by reviewing relevant literature regarding the ultrasonographic features of hepatic lesions. Using this lexicon, two abdominal radiologists determined the presence or absence of each ultrasonographic feature for the included hepatic lesions. Independent factors associated with malignancy and interobserver agreement were determined by logistic regression analysis and kappa statistics, respectively.

RESULTS

Larger tumor size (odds ratio [OR], 1.12; 95% confidence interval [CI], 1.06-1.183; P<0.001), multinodular confluent morphology (OR, 7.712; 95% CI, 1.053-56.465; P=0.044), thick hypoechoic rim (OR, 5.878; 95% CI, 2.681-12.888; P<0.001), and posterior acoustic enhancement (OR, 3.077; 95% CI, 1.237-7.655; P=0.016) were independently associated with malignant lesions. In a subgroup analysis of lesions <2 cm, none of the ultrasonographic features were significantly associated with malignancy or benignity. Interobserver agreement for morphology was fair (κ=0.36), while those for rim (κ=0.427), echogenicity (κ=0.549), and posterior acoustic enhancement (κ=0.543) were moderate.

CONCLUSIONS

For hepatic lesions larger than 2 cm, some ultrasonography (US) features might be suggestive of malignancy. We propose a lexicon that may be useful for surveillance US.

A randomized trial of intensive versus minimal surveillance of patients with resected Dukes B2-C colorectal carcinoma

BACKGROUND

Colorectal cancer is the third most common and the third most lethal cancer in both men and women in developed countries. About 75% of cases are first diagnosed when the disease is classified as localized or regional, undergo potentially curative treatment and enter a post-treatment surveillance program. Although such programs drain significant resources from health systems, empirical evidence of their efficacy is scanty.

PATIENTS AND METHODS

Dukes B2-C colorectal cancer patients who had no evidence of disease at the end of their front-line treatment (surgery and adjuvant radiochemotherapy, if indicated) were eligible for the trial and randomized to two different surveillance programs. These programs differed greatly in the frequency of diagnostic imaging. They had similar schedules of physical examinations and carcinoembryonic antigen (CEA) assessments. Patients received baseline and yearly health-related quality-of-life (HR-QoL) questionnaires. Primary outcomes were overall survival (OS) and QoL.

RESULTS

From 1998 to 2006, 1228 assessable patients were randomized, 933 with colon cancer and 295 with rectal cancer. More than 90% of patients had the expected number of diagnostic procedures. Median follow-up duration was 62 months [interquartile range (IQR) 51-86] in the minimal surveillance group and 62 months (IQR 50-85) in the intensive group. At primary analysis, 250 patients had recurred and 218 had died. Intensive surveillance anticipated recurrence, as shown by a significant difference in mean disease-free survival of 5.9 months. Comparison of OS curves of the whole intention-to-treat population showed no statistically significant differences. HR-QoL of life scores did not differ between regimens.

CONCLUSION

Our findings support the conclusions of other randomized clinical trials, which show that early diagnosis of cancer recurrence is not associated with OS benefit.

CLINICALTRIALSGOV

NCT02409472.

Sonographic characterization of 271 hepatic hemangiomas with typical appearance on CT imaging

PURPOSE

Hepatic hemangioma is the most frequent benign solid tumor that requires differentiation from hepatic malignancy on ultrasonography. Useful ultrasound findings are therefore required for diagnosis.

SUBJECTS AND METHODS

The following factors were investigated for 271 masses diagnosed as hepatic hemangioma by contrast-enhanced computed tomography (CT) in 188 patients: hepatic subsegment location, shape, maximum diameter, internal echo level, hyperechoic rim, posterior echoes, marginal hypoechoic band (halo), lateral shadow, blood flow signal in the central portion of the mass, and underlying liver disease.

RESULTS

Hepatic masses were classified by internal echo pattern as homogeneous hyperechoic (35.0%), homogeneous hypoechoic (22.9%), isoechoic (5.2%), mixed hyperechoic (22.1%), or mixed hypoechoic (14.8%) masses. Twelve masses were isoechoic, and could be recognized by the hyperechoic rim. Posterior echo enhancement was present in 66 masses. There were no cases of posterior echo attenuation. A halo was present in six masses, with the underlying condition being fatty infiltrated liver in two masses; a hypoechoic region with a small amount of fat deposit was present around the mass, and this resembled a halo. This finding was termed a "pseudohalo." There were no masses in which a lateral shadow was observed. In terms of blood flow signals in the central portion of the mass, pulsatile flow was present in only one mass.

CONCLUSIONS

Important ultrasonographic findings of hepatic hemangioma are characterized as the absence of lateral shadow (100%) and no attenuation of posterior echoes (100%), while the presence of a hyperechoic rim is useful for detecting isoechoic hemangioma.

Diagnostic imaging of hepatocellular carcinoma: recent progress

The diagnostic imaging of hepatocellular carcinoma (HCC) has recently undergone marked progress. The advent of the ultrasound (US) contrast agent Sonazoid, approved in January 2007, and magnetic resonance imaging (MRI) with the liver-specific MRI contrast agent gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA-MRI), approved in January 2008, are of particular significance. Sonazoid contrast-enhanced US (Sonazoid-CEUS) is useful not only for the diagnosis of HCC, but also for guiding treatment and assessing treatment response. Sonazoid-CEUS has proven to be particularly effective for screening and staging, which used to be considered impossible with CEUS, through the introduction of the newly developed diagnostic technique of defect reperfusion imaging. It is still not possible if other vascular agents such as SonoVue and Definity are used. In particular, Gd-EOB-DTPA-MRI has been suggested to be much more reliable in the differentiation of early HCC from precancerous dysplastic nodules than any other modalities such as multidetector raw computed tomography, dynamic MRI, and superparamagnetic iron oxide-MRI. A decrease in contrast uptake in the hepatocyte phase observed on EOB-MRI is strongly suggestive of cancer, and the absence of early staining in the arterial phase suggests early HCC. The differential diagnostic capacity of Gd-EOB-DTPA-MRI is considered to far exceed that of what were previously the most useful imaging techniques, computed tomography (CT) during hepatic arteriography or CT during arterial portography, and to be comparable to that of the pathological diagnosis by pathologists specialized in liver.