Contrast-enhanced sonography versus biopsy for the differential diagnosis of thrombosis in hepatocellular carcinoma patients

Liver transplantation for advanced hepatocellular carcinoma: Controversy over portal vein tumor thrombosis

Liver transplantation (LT) is considered the ideal treatment for hepatocellular carcinoma (HCC) concurrent with underlying cirrhotic liver disease. As well-known, LT for HCC based on the Milan criteria has shown satisfactory outcomes. However, numerous expanded transplantation criteria were proposed to benefit more patients for LT and showed comparable survivals as well. In addition, a modest expansion of transplantation criteria for HCC may be acceptable on the basis of the consensus within the transplantation community. Nonetheless, LT in patients with advanced HCC and portal vein tumor thrombosis (PVTT) recently has received attention and has been reported by many transplantation centers despite being contraindicated. Of those, the LT outcomes in certain HCC patients with PVTT were favorable. Additionally, the advancement of multimodality treatments and the evolution of systemic therapies have emerged as promising therapeutic options for downstaging advanced HCC prior to LT. Somehow, advanced HCC with PVTT could be downstaged to become eligible for LT through these multidisciplinary approaches. Although the available evidence of LT for HCC with PVTT is limited, it is hoped that LT may soon be more widely indicated for these patients. Nevertheless, several unknown factors associated with LT for HCC remain to be explored. Herein, this review aimed to update the developments in LT for patients with advanced HCC.

Role of contrast-enhanced ultrasound for differentiation of benign vs. malignant portal vein thrombosis in hepatocellular carcinoma - A systematic review a meta-analysis

Introduction/Purpose

Patients with cirrhosis and hepatocellular carcinoma (HCC) can develop both benign and malignant portal vein thrombosis (PVT). Characterising the nature of PVT is important for planning an optimal therapeutic strategy. In the absence of typical findings or contraindications to computed tomography (CT) or magnetic resonance imaging (MRI), contrast-enhanced ultrasound (CEUS) could help in this differentiation. The present meta-analysis aimed to evaluate the performance of CEUS for characterising PVT in patients with HCC.

Methods

Electronic databases of PubMed, Embase and Scopus were searched from inception to 31 December 2022 for studies analysing the role of CEUS in the differentiation of benign and malignant PVT in HCC. Using the bivariate random effect model, pooled sensitivity and specificity were calculated, and the summary receiver operating characteristic (sROC) curve was plotted.

Results

A total of 12 studies with data from 712 patients were included in the meta-analysis. The pooled sensitivity and specificity of CEUS for the diagnosis of tumour in vein were 97.0% (95% CI: 93.0-98.7) and 96.8% (95% CI: 92.1-98.7), respectively, without significant heterogeneity. A sROC curve was plotted, and the area under the receiver operating characteristic was 0.99 (95% CI: 0.98-1.00). Despite the presence of publication bias, sensitivity analysis did not show any change in sensitivity and specificity.

Discussion

Our meta-analysis summarises the accuracy data from 12 studies, including >700 subjects. Contrast-enhanced ultrasound had excellent diagnostic accuracy with pooled sensitivity and specificity of 97.5% (95% CI: 93.5-99.1) and 98.2% (95% CI: 91.5-99.6), respectively, without any significant heterogeneity. Additionally, the pooled positive LR, negative LR and DOR were 54.6 (95% CI: 11.1-25.6), 0.02 (0.01-0.07) and 2186.8 (318.3-15022.2), respectively. A positive result increases the pretest probability of malignant PVT from 50% to 98%, whereas a negative result decreases it from 50% to 2%. Most of the studies included in our meta-analysis used identical techniques and 6-12-month follow-up scans to check for thrombus progression or regression. Our analysis showed no significant heterogeneity in the studies, and area under receiver operating characteristic curve (AUROC) with 95% CI was 1.00 (95% CI: 0.99-1.00). This critical meta-analysis thus propels CEUS to the forefront for differentiating benign from tumoural PVT and suggests routinely using CEUS in patients presenting with HCC and evidence of thrombus on greyscale ultrasound.

Conclusion

Contrast-enhanced ultrasound is an effective diagnostic modality differentiation of benign and malignant PVT in patients with HCC and can be an alternative modality to CT or MRI. Further studies are required to study the role of CEUS as initial diagnostic modality for the characterisation of PVT in HCC.

The Role of Contrast-Enhanced Ultrasound (CEUS) in the Detection of Neoplastic Portal Vein Thrombosis in Patients with Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the principal primary liver cancer and one of the most frequent malignant tumors worldwide in patients with chronic liver disease. When diagnosed at an advanced stage, it is often associated with portal vein tumor thrombosis (PVTT), which heavily affects patients' prognosis. Imaging evaluation is crucial in PVTT detection and staging; computed tomography and magnetic resonance are the principal diagnostic tools. Contrast-enhanced ultrasound (CEUS) is a non-invasive and easily repeatable method that can also be used in patients with impaired renal function. It represents an important means for the identification of PVTT, particularly differentiating neoplastic and non-neoplastic thrombosis through the analysis of ultrasound enhancement characteristics of the thrombosis (arterial hyperenhancement and portal washout), thus allowing more refined disease staging, appropriate treatment planning, and response evaluation, along with prognosis assessment.

Characterization of focal liver lesions using sulphur hexafluoride (SF6) microbubble contrast-enhanced ultrasonography

Background

Focal hepatic lesions incidentally detected during ultrasound usually need further step for proper characterization. The aim of this study was to highlight the efficacy of microbubble contrast-enhanced ultrasonography (CEUS) in characterization of focal liver lesions. This prospective study was conducted on 60 patients presented with hepatic focal lesions in the period from January 2019 to June 2020. CEUS studies were performed after a baseline conventional ultrasound with the same machine by the same operator. The ultrasound contrast agent used is second-generation US contrast agent. The enhancement patterns of the hepatic lesions were studied during the vascular phases up to 5 min and the data were correlated with histopathology, triphasic contrast-enhanced CT, and clinical follow-up.

Results

CEUS demonstrated a sensitivity of 94.2%, specificity of 88.9%, positive predictive value of 91%, negative predictive value of 94.1%, and accuracy of 92.3% for characterization of hepatic focal lesions, compared to a sensitivity of 100%, specificity of 81.8%, positive predictive value of 84%, negative predictive value of 100%, and accuracy of 90.7% for triphasic CT.

Conclusion

CEUS is an effective tool in characterization of HFLs and recommended as a second diagnostic step after conventional ultrasound to immediately establish the diagnosis especially in patients with contraindications to CECT.

Portal vein thrombosis in patients with chronic liver diseases: From conventional to quantitative imaging

Portal vein thrombosis is a pathological condition characterized by the lumen occlusion of the portal vein and its intrahepatic branches, commonly associated to chronic liver diseases. Portal vein thrombosis is often asymptomatic and discovered as an incidental finding in the follow-up of chronic hepatopathy. Imaging plays a pivotal role in the detection and characterization of portal vein thrombosis in patients with hepatocellular carcinoma. Ultrasound and Color-Doppler ultrasound are usually the first-line imaging modalities for its detection, but they have limits related to operator-experience, patient size, meteorism and the restrained field-of view. Unenhanced cross-sectional imaging doesn't provide specific signs of portal vein thrombosis except under certain specific circumstances. Conventional contrast-enhanced imaging can depict portal vein thrombosis as an endoluminal filling defect best detected in venous phase and can differentiate between non-neoplastic and neoplastic thrombus based on the contrast enhanced uptake, but not always rule-out the malignant nature. Functional and quantitative imaging techniques and software seem to be more accurate. The purpose of this work is to provide the reader with an accurate overview focused on the main imaging features of portal vein thrombosis.

Guidelines and Good Clinical Practice Recommendations for Contrast Enhanced Ultrasound (CEUS) in the Liver - Update 2020 - WFUMB in Cooperation with EFSUMB, AFSUMB, AIUM, and FLAUS

The present, updated document describes the fourth iteration of recommendations for the hepatic use of contrast enhanced ultrasound (CEUS), first initiated in 2004 by the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB). The previous updated editions of the guidelines reflected changes in the available contrast agents and updated the guidelines not only for hepatic but also for non-hepatic applications.The 2012 guideline requires updating as previously the differences of the contrast agents were not precisely described and the differences in contrast phases as well as handling were not clearly indicated. In addition, more evidence has been published for all contrast agents. The update also reflects the most recent developments in contrast agents, including the United States Food and Drug Administration (FDA) approval as well as the extensive Asian experience, to produce a truly international perspective.These guidelines and recommendations provide general advice on the use of ultrasound contrast agents (UCA) and are intended to create standard protocols for the use and administration of UCA in liver applications on an international basis to improve the management of patients.

Guidelines and Good Clinical Practice Recommendations for Contrast-Enhanced Ultrasound (CEUS) in the Liver-Update 2020 WFUMB in Cooperation with EFSUMB, AFSUMB, AIUM, and FLAUS

The present, updated document describes the fourth iteration of recommendations for the hepatic use of contrast-enhanced ultrasound, first initiated in 2004 by the European Federation of Societies for Ultrasound in Medicine and Biology. The previous updated editions of the guidelines reflected changes in the available contrast agents and updated the guidelines not only for hepatic but also for non-hepatic applications. The 2012 guideline requires updating as, previously, the differences in the contrast agents were not precisely described and the differences in contrast phases as well as handling were not clearly indicated. In addition, more evidence has been published for all contrast agents. The update also reflects the most recent developments in contrast agents, including U.S. Food and Drug Administration approval and the extensive Asian experience, to produce a truly international perspective. These guidelines and recommendations provide general advice on the use of ultrasound contrast agents (UCAs) and are intended to create standard protocols for the use and administration of UCAs in liver applications on an international basis to improve the management of patients.

Use of Contrast-Enhanced Ultrasonography for the Characterization of Tumor Thrombi in Seven Dogs

Simple Summary

Some neoplasia—such as adrenal and thyroid glands tumors—have been associated with “tumor thrombi” both in humans and dogs. The detection and characterization of these venous tumor thrombi is important for both surgical planning and prognosis. In human medicine, contrast-enhanced ultrasonography (CEUS) is considered an accurate diagnostic technique for differentiating malignant from benign portal vein thrombosis in hepatocellular carcinomas. Data regarding the characteristics of tumor thrombi in dogs are currently lacking. Therefore, the aim of this study was to assess the feasibility of CEUS for the characterization of malignant venous thrombosis in dogs. On the basis of our results, CEUS appeared to be useful in the detection of malignant intravascular invasion; contrast uptake of the thrombus was present in all cases. In addition, CEUS may clearly detect newly formed vessels within the thrombus, and arterial-phase enhancement and washout in the venous phase were the main features in malignant thrombosis in our dogs. As CEUS is an easy to perform, noninvasive technique, its application in the detection of malignant thrombosis in dogs may be used to improve the diagnosis in oncological canine patients.

Abstract

Tumors of adrenal and thyroid glands have been associated with vascular invasions—so-called tumor thrombi, both in humans and dogs. The detection and characterization of venous thrombi is an important diagnostic step in patients with primary tumors for both surgical planning and prognosis. The aim of this study was to describe the use of contrast-enhanced ultrasonography (CEUS) for the characterization of tumor thrombi. Dogs with tumor thrombus who underwent bi-dimensional ultrasound (B-mode US) and CEUS were included. Seven dogs were enrolled in this retrospective case series. On B-mode US, all thrombi were visualized, and vascular distension and thrombus-tumor continuity were seen in three and two cases, respectively. On color Doppler examination, all thrombi were identified, seemed non-occlusive and only two presented vascularity. On CEUS, arterial-phase enhancement and washout in the venous phase were observed in all cases. Non-enhancing areas were identified in the tumor thrombi most likely representing non-vascularized tissue that could potentially be embolized in the lungs after fragmentation of the tumor thrombi. On the basis of these preliminary study, CEUS appeared to be useful for the characterization of malignant intravascular invasion.

MRI-Based Radiomics Signature: A Potential Biomarker for Identifying Glypican 3-Positive Hepatocellular Carcinoma

BACKGROUND

Glypican 3 (GPC3) expression has proved to be a critical risk factor related to prognosis in hepatocellular carcinoma (HCC) patients.

PURPOSE

To investigate the performance of MRI-based radiomics signature in identifying GPC3-positive HCC.

STUDY TYPE

Retrospective.

POPULATION

An initial cohort of 293 patients with pathologically confirmed HCC was involved in this study, and patients were randomly divided into training (195) and validation (98) cohorts.

FIELD STRENGTH/SEQUENCES

Contrast-enhanced T₁ -weight MRI was performed with a 1.5T scanner.

ASSESSMENT

A total of 853 radiomic features were extracted from the volume imaging. Univariate analysis and Fisher scoring were utilized for feature reduction. Subsequently, forward stepwise feature selection and radiomics signature building were performed based on a support vector machine (SVM). Incorporating independent risk factors, a combined nomogram was developed by multivariable logistic regression modeling.

STATISTICAL TESTS

The predictive performance of the nomogram was calculated using the area under the receive operating characteristic curve (AUC). Decision curve analysis (DCA) was applied to estimate the clinical usefulness.

RESULTS

The radiomics signature consisting of 10 selected features achieved good prediction efficacy (training cohort: AUC = 0.879, validation cohort: AUC = 0.871). Additionally, the combined nomogram integrating independent clinical risk factor α-fetoprotein (AFP) and radiomics signature showed improved calibration and prominent predictive performance with AUCs of 0.926 and 0.914 in the training and validation cohorts, respectively.

DATA CONCLUSION

The proposed MR-based radiomics signature is strongly related to GPC3-positive. The combined nomogram incorporating AFP and radiomics signature may provide an effective tool for noninvasive and individualized prediction of GPC3-positive in patients with HCC. J. MAGN. RESON. IMAGING 2020;52:1679-1687.

Imaging and implications of tumor thrombus in abdominal malignancies: reviewing the basics

Extension of tumor tissue within a vein is a recognized prognostic factor in abdominal malignancy because of its influence on tumor staging and selection of therapeutic management. With the advent of newer surgical techniques, and variable treatment strategies, imaging plays a crucial role in categorizing patients according to the tumor resectability and vascular reconstruction techniques during surgery. Understanding the clinical impact of tumor thrombus increases the awareness of the radiologist about the key findings in tumor staging and decision-making of surgical approach. Ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MRI) can be used individually and in combination to accurately assess the tumor thrombus. In our pictorial review, we will discuss the imaging findings and clinical consequences of tumor thrombosis in abdominal malignancies, including hepatocellular carcinoma, pancreatic neuroendocrine tumor, renal cancer, and adrenal cortical carcinoma.

Grading of hepatocellular carcinoma based on diffusion weighted images with multiple b-values using convolutional neural networks

PURPOSE

To effectively grade hepatocellular carcinoma (HCC) based on deep features derived from diffusion weighted images (DWI) with multiple b-values using convolutional neural networks (CNN).

MATERIALS AND METHODS

Ninety-eight subjects with 100 pathologically confirmed HCC lesions from July 2012 to October 2018 were included in this retrospective study, including 47 low-grade and 53 high-grade HCCs. DWI was performed for each subject with a 3.0T MR scanner in a breath-hold routine with three b-values (0,100, and 600 s/mm² ). First, logarithmic transformation was performed on original DWI images to generate log maps (logb0, logb100, and logb600). Then, a resampling method was performed to extract multiple 2D axial planes of HCCs from the log map to increase the dataset for training. Subsequently, 2D CNN was used to extract deep features of the log map for HCCs. Finally, fusion of deep features derived from three b-value log maps was conducted for HCC malignancy classification. Specifically, a deeply supervised loss function was devised to further improve the performance of lesion characterization. The data set was split into two parts: the training and validation set (60 HCCs) and the fixed test set (40 HCCs). Four-fold cross validation with 10 repetitions was performed to assess the performance of deep features extracted from single b-value images for HCC grading using the training and validation set. Receiver operating characteristic curve (ROC) and area under the curve (AUC) values were used to assess the characterization performance of the proposed deep feature fusion method to differentiate low-grade and high-grade in the fixed test set.

RESULTS

The proposed fusion of deep features derived from logb0, logb100, and logb600 with deeply supervised loss function generated the highest accuracy for HCC grading (80%), thus outperforming the method of deep feature derived from the ADC map directly (72.5%), the original b0 (65%), b100 (68%), and b600 (70%) images. Furthermore, AUC values of the deep features of the ADC map, the deep feature fusion with concatenation, and the proposed deep feature fusion with deeply supervised loss function were 0.73, 0.78, and 0.83, respectively.

CONCLUSION

The proposed fusion of deep features derived from the logarithm of the three b-value images yields high performance for HCC grading, thus providing a promising approach for the assessment of DWI in lesion characterization.

Tumor thrombus: incidence, imaging, prognosis and treatment

Intravascular tumor extension, also known as tumor thrombus, can occur in many different types of cancer. Those with the highest proclivity include Wilm's tumor, renal cell carcinoma (RCC), adrenal cortical carcinoma (ACC) and hepatocellular carcinoma (HCC). The presence of tumor thrombus markedly worsens prognosis and impacts treatment approach. Imaging plays a key role in its diagnosis. Endovascular methods also play a large role in treatment.

Superparamagnetic iron oxide-enhanced magnetic resonance imaging is useful in predicting malignant potential of vascular transformation of hypointense hypovascular nodules on gadoxetic acid-enhanced magnetic resonance imaging

AIM

To examine whether superparamagnetic iron oxide (SPIO)-enhanced magnetic resonance imaging (MRI) can be used to assess the malignant potential of hepatic hypovascular nodules showing hypointensity during the hepatobiliary phase (HBP) on gadoxetic acid (Gd-EOB-DTPA)-enhanced MRI.

METHODS

The study included 42 patients with chronic liver disease who had small hypovascular nodules (5-15 mm) showing hypointensity during the HBP on Gd-EOB-DTPA-enhanced MRI. The SPIO-enhanced T2-weighted MRI analyzed whether the signal intensity of each nodule was high. Nodules were prospectively followed up until hypervascularization by periodic Gd-EOB-DTPA-enhanced MRI. Initial MRI findings and clinical variables were used to analyze predictive factors for hypervascularization.

RESULTS

We analyzed 77 nodules, of which 19 (25%) showed hypervascularization during the observation period. The cumulative rates for hypervascularization were 11% and 22% at 1 and 2 years, respectively. Hyperintensity was observed in 12 nodules (16%) on SPIO-enhanced T2-weighted MRI; among these, 7 (58%) showed hypervascularization, whereas 12 (18%) of the remaining 65 nodules without hyperintensity showed hypervascularization (P = 0.007). A Cox model revealed that independent predictors of hypervascularization included hyperintense nodules on SPIO-enhanced MRI (P < 0.001). The cumulative rates for hypervascularization in hyperintense nodules on SPIO-enhanced MRI were 52% at 1 year, whereas these rates were 3% for non-hyperintense nodules.

CONCLUSION

Superparamagnetic iron oxide-enhanced MRI is useful for predicting the malignant potential of vascular transformation of hypovascular nodules with hypointensity observed in the HBP on Gd-EOB-DTPA-enhanced MRI.

Percutaneous electrochemotherapy in the treatment of portal vein tumor thrombosis at hepatic hilum in patients with hepatocellular carcinoma in cirrhosis: A feasibility study

AIM

To treated with electrochemotherapy (ECT) a prospective case series of patients with liver cirrhosis and Vp3-Vp4- portal vein tumor thrombus (PVTT) from hepatocellular carcinoma (HCC), in order to evaluate the feasibility, safety and efficacy of this new non thermal ablative technique in those patients.

METHODS

Six patients (5 males and 1 female), aged 61-85 years (mean age, 70 years), four in Child-Pugh A and two in Child-Pugh B class, entered our study series. All patients were studied with three-phase computed tomography (CT), contrast enhanced ultrasound (CEUS) and ultrasound-guided percutaneous biopsy of the thrombus before ECT. All patients underwent ECT treatment (Cliniporator Vitae^®, IGEA SpA, Carpi, Modena, Italy) of Vp3-Vp4 PVTT in a single session. At the end of the procedure a post-treatment biopsy of the thrombus was performed. Scheduled follow-up in all patients entailed: CEUS within 24 h after treatment; triphasic contrast-enhanced CT and CEUS at 3 mo after treatment and every six months thereafter.

RESULTS

Post-treatment CEUS showed complete absence of enhancement of the treated thrombus in all cases. Post-treatment biopsy showed apoptosis and necrosis of tumor cells in all cases. The follow-up ranged from 9 to 20 mo (median, 14 mo). In 2 patients, the follow-up CT and CEUS demonstrated complete patency of the treated portal vein. Other 3 patients showed a persistent avascular non-tumoral shrinked thrombus at CEUS and CT during follow-up. No local recurrence was observed at follow-up CT and CEUS in 5/6 patients. One patient was lost to follow-up because of death from gastrointestinal hemorrage 5 wk after ECT.

CONCLUSION

In patients with cirrhosis, ECT seems effective and safe for curative treatment of Vp3-Vp4 PVTT from HCC.

Malignancy characterization of hepatocellular carcinomas based on texture analysis of contrast-enhanced MR images

PURPOSE

To investigate the performance of texture analysis in characterizing malignancy of hepatocellular carcinomas (HCCs) based on contrast-enhanced magnetic resonance imaging (MRI).

MATERIALS AND METHODS

Gd-DTPA contrast-enhanced MRI data of 46 consecutive subjects with resected HCC were retrieved. The mean intensity and gray-level run-length nonuniformity (GLN) were quantified as the discriminative features based on the arterial phase images and compared between groups with different histological grading using independent Student's t-test or Welch-Satterthwaite approximate t-test for data following a normal distribution and Mann-Whitney U-test for data violating the normal distribution. The performance of texture features in differentiating the biological aggressiveness of HCC was assessed using receiver operating characteristic (ROC) analysis. P < 0.05 was set as the significance level.

RESULTS

Low-grade HCCs had increased mean intensity and decreased GLN in four directions, as compared with high-grade HCCs (P < 0.0005). A cutoff value of 739.37 for the average intensity resulted in an optimal sensitivity of 76% and specificity of 100% for histological grading discrimination. Cutoff values of 34.18, 66.59, 36.82, and 80.31 for the GLN in four directions (0°, 45°, 90°, 135°) resulted in an optimal sensitivity of 92%, 84%, 68%, 76% and specificity 66.70%, 71.40%, 85.70%, 76.20%, respectively. The areas under the ROC curve for the average intensity and GLN in four directions were 0.918, 0.846, 0.836, 0.827, and 0.838, respectively.

CONCLUSION

Texture features indexed by mean and GLN based on the arterial phase images reflect biologic aggressiveness, and may have potential applications in predicting the histological grading of HCC preoperatively. Evidence level: 4 J. MAGN. RESON. IMAGING 2017;45:1476-1484.

Clinical implications for imaging of vascular invasion in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the second largest cause of cancer mortality in the world, with vascular invasion being one of the most important prognostic factors. HCC with tumor thrombus was traditionally considered to have very limited treatment options. However, multiple promising treatment strategies have emerged in recent years, with diagnostic and interventional radiologists playing a major role in patient management. We provide a comprehensive update on the diagnosis and management of HCC with vascular invasion and the role of the radiologist in this condition.

Differentiating malignant from benign thrombosis in hepatocellular carcinoma: contrast-enhanced ultrasound

BACKGROUND

To determine the accuracy of contrast-enhanced ultrasonography (CEUS) in differentiating malignant and benign venous thrombosis complicating hepatocellular carcinoma (HCC).

METHODS

Fifty patients (M:F = 41:9; age range 46-83 years) with HCC and venous thrombosis [portal vein (PV) in 45 and hepatic vein (HV) in 5] detected on CT or MR scan were evaluated with CEUS. Reference standard of malignant and benign thrombosis was based on serial clinicoradiologic follow-up (n = 43) or pathology (n = 7). Two independent, blinded readers retrospectively recorded the enhancement features of the venous thrombosis and diagnosed as benign or malignant thrombosis with a five-point confidence scale. Receiver operating characteristic (ROC) curves were calculated to determine the diagnostic performance of CEUS in differentiating malignant from benign thrombosis. Confidence level ratings were also used to calculate the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for the diagnosis of malignant thrombosis. Inter-reader agreement was calculated using κ statistics in each assessed finding. Gray scale and Doppler characteristics of primary tumor and thrombosis were also assessed.

RESULTS

Of the 50 patients, 37 were malignant (33 with PV thrombosis and 4 with HV thrombosis) and 13 were benign (12 with PV thrombosis and 1 with HV thrombosis). In ROC curve analysis for differentiating malignant from benign thrombosis, Az was 0.947 (CI 0.841-0.991) for reader 1 and 0.958 (CI 0.861-0.995) for reader 2 with excellent inter-reader agreement (κ = 0.86). When the confidence level ratings of 1 or 2 were considered malignant thrombosis, the sensitivity, specificity, PPV, and NPV in differentiating malignant from benign thrombosis were 100%, 83%, 95%, and 100% for reader 1 and 100%, 92%, 97%, and 100% for reader 2.

CONCLUSION

CEUS is useful to differentiate malignant and benign venous thrombosis associated with HCC with high diagnostic accuracy.

Considerations regarding current diagnosis and prognosis of hepatocellular carcinoma

Hepatocellular carcinoma is a major health issue, ranked the fifth most common tumor and currently being responsible for a third of the cancer-related deaths globally, with an ever-increasing number of fatalities. Current advances in contrast-enhanced imaging techniques such as contrast-enhanced ultrasonography, multi-detector computed tomography and diffusion-weighted magnetic resonance imaging are improving the rate of hepatocellular carcinoma diagnosis. Contrast-enhanced ultrasonography has widely become the first choice in liver tumor assessment, as it is faster, simpler and safer than other forms of diagnostic imaging. On the other hand, cross sectional computed tomography is frequently employed when a hepatic formation is suspected of malignancy and allows a more accurate characterization of lesions through multiphasic multi-detector computed tomography technology. Diffusion weighted magnetic resonance imaging represents another addition to the wide range of diagnostic and prognostic techniques available for patients with hepatocellular carcinoma and is currently regarded as one of the best tools for the characterization of these lesions. Furthermore, groundbreaking biomarkers for hepatocellular carcinoma are being discovered, although alpha-fetoprotein remains one of the most frequently used serum test in the early stages. Nonetheless, further advances are required for the detection of small liver carcinomas.

FDG-Avid Portal Vein Tumor Thrombosis from Hepatocellular Carcinoma in Contrast-Enhanced FDG PET/CT

OBJECTIVES

In this study, we aimed to describe the characteristics of portal vein tumor thrombosis (PVTT), complicating hepatocellular carcinoma (HCC) in contrast-enhanced FDG PET/CT scan.

METHODS

In this retrospective study, 9 HCC patients with FDG-avid PVTT were diagnosed by contrast-enhanced fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT), which is a combination of dynamic liver CT scan, multiphase imaging, and whole-body PET scan. PET and CT DICOM images of patients were imported into the PET/CT imaging system for the re-analysis of contrast enhancement and FDG uptake in thrombus, the diameter of the involved portal vein, and characteristics of liver tumors and metastasis.

RESULTS

Two patients with previously untreated HCC and 7 cases with previously treated HCC had FDG-avid PVTT in contrast-enhanced FDG PET/CT scan. During the arterial phase of CT scan, portal vein thrombus showed contrast enhancement in 8 out of 9 patients (88.9%). PET scan showed an increased linear FDG uptake along the thrombosed portal vein in all patients. The mean greatest diameter of thrombosed portal veins was 1.8 ± 0.2 cm, which was significantly greater than that observed in normal portal veins (P<0.001). FDG uptake level in portal vein thrombus was significantly higher than that of blood pool in the reference normal portal vein (P=0.001). PVTT was caused by the direct extension of liver tumors. All patients had visible FDG-avid liver tumors in contrast-enhanced images. Five out of 9 patients (55.6%) had no extrahepatic metastasis, 3 cases (33.3%) had metastasis of regional lymph nodes, and 1 case (11.1%) presented with distant metastasis. The median estimated survival time of patients was 5 months.

CONCLUSION

The intraluminal filling defect consistent with thrombous within the portal vein, expansion of the involved portal vein, contrast enhancement, and linear increased FDG uptake of the thrombus extended from liver tumor are findings of FDG-avid PVTT from HCC in contrast-enhanced FDG PET/CT.

Guidelines and good clinical practice recommendations for Contrast Enhanced Ultrasound (CEUS) in the liver - update 2012: A WFUMB-EFSUMB initiative in cooperation with representatives of AFSUMB, AIUM, ASUM, FLAUS and ICUS

Initially, a set of guidelines for the use of ultrasound contrast agents was published in 2004 dealing only with liver applications. A 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 non-liver applications. Time has moved on, and the need for international guidelines on the use of CEUS in the liver has become apparent. The present document describes the third iteration of recommendations for the hepatic use of contrast enhanced ultrasound (CEUS) using contrast specific imaging techniques. This joint WFUMB-EFSUMB initiative has implicated experts from major leading ultrasound societies worldwide. These liver CEUS guidelines are simultaneously published in the official journals of both organizing federations (i.e., Ultrasound in Medicine and Biology for WFUMB and Ultraschall in der Medizin/European Journal of Ultrasound for EFSUMB). These guidelines and recommendations provide general advice on the use of all currently clinically available ultrasound contrast agents (UCA). They are intended to create standard protocols for the use and administration of UCA in liver applications on an international basis and improve the management of patients worldwide.

Portal vein thrombosis with contrast-enhanced ultrasound in a patient with hepatocellular carcinoma: a case study

Portal vein thrombosis (PVT) is the presence of thrombus in the portal vein that causes partial or complete occlusion. It is prevalent in hepatocellular carcinoma (HCC), where it can be either bland or malignant depending on the presence of invasion. Recent studies have identified contrast-enhanced ultrasound (CEUS) as the most reliable method of imaging to make this distinction. The arterial neovascularisation that is evident in a neoplastic thrombus can be visualised on CEUS with enhancement and pulsation, witnessed in real-time. This case study describes the use of contrast-enhanced ultrasound used as a non-invasive method to define the bland and malignant components of portal vein thrombosis in a 76-year-old male with hepatocellular carcinoma and cirrhosis.

Prediction of microvascular invasion of hepatocellular carcinoma: usefulness of peritumoral hypointensity seen on gadoxetate disodium-enhanced hepatobiliary phase images

PURPOSE

To determine whether peritumoral hypointensity seen on hepatobiliary phase images of preoperative gadoxetate disodium-enhanced magnetic resonance imaging (EOB-MRI) is useful for predicting microvascular invasion of hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

This study was approved by the Institutional Review Board. In all, 104 HCC masses in 104 patients who had undergone EOB-MRI and liver surgery within 1 month after EOB-MRI were evaluated. Two radiologists independently recorded the presence of a peritumoral hypointensity on hepatobiliary phase. Interobserver agreement was assessed and consensus records were used. Tumor size was measured. A chi-square test and independent t-test were used for univariate analysis. Multiple logistic regression was performed to determine factors for predicting microvascular invasion. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of peritumoral hypointensity were calculated.

RESULTS

Sixty HCCs had microvascular invasion and 44 did not. Interobserver agreement in determining peritumoral hypointensity was excellent (κ = 0.83). By univariate analysis, peritumoral hypointensity and tumor size were significant for predicting microvascular invasion of HCC. On multiple logistic regression analysis, only peritumoral hypointensity was significant in predicting microvascular invasion of HCC (P = 0.013). The sensitivity, specificity, PPV, and NPV of peritumoral hypointensity were 38.3%, 93.2%, 88.5%, and 52.6%, respectively.

CONCLUSION

Peritumoral hypointensity on the hepatobiliary phase of EOB-MRI is not sensitive but has high specificity for predicting microvascular invasion of HCC.

Validation of an extension of the international non-invasive criteria for the diagnosis of hepatocellular carcinoma to the characterization of macroscopic portal vein thrombosis

BACKGROUND AND AIM

We aimed to validate the non-invasive criteria for the characterization of portal vein thrombosis (PVT) in patients with cirrhosis and hepatocellular carcinoma (HCC). In a prospective study, we examined the impact of arterial hypervascularity, as established by the European Association for the Study of the Liver and the American Association for the Study of Liver Diseases recommendations for the non-invasive diagnosis of HCC, as a criterion for characterizing macroscopic PVT (EASL/AASLD extension criteria).

METHODS

A total of 96 cases of PVT detected using ultrasonography in patients with cirrhosis and HCC were included in the study. When coincidental arterial hypervascularity was detected by contrast perfusional ultrasonography and helical computed tomography, the thrombus was considered malignant according to our EASL/AASLD extension criteria. In all cases, an ultrasound-guided biopsy examination of the thrombus was performed.

RESULTS

Coincidental hypervascularity was found in 54 of 96 nodules (56.2%), and all were malignant upon biopsy (100% positive predictive value). Twenty-four (25%) had negative results with both techniques (non-vascular thrombus). Biopsies showed HCC in five non-vascular thrombi (5.3% of all thrombi) and in 13 of 18 thrombi with a hypervascularity result from only one technique.

CONCLUSIONS

The EASL/AASLD extension criteria for non-invasive diagnosis of malignant thrombosis were satisfied in 75.2% of malignant thrombi; thus, a biopsy is frequently required in this setting. However, in the presence of coincidental hypervascularity of a thrombus with both techniques, a biopsy is not required (absolute positive predictive value for malignancy). Relying on imaging techniques in thrombi could miss the diagnosis of malignant portal invasion in up to 24.9% of cases.

APASL and AASLD Consensus Guidelines on Imaging Diagnosis of Hepatocellular Carcinoma: A Review

Consensus guidelines for radiological diagnosis of hepatocellular carcinoma (HCC) have been drafted by several large international working groups. This article reviews the similarities and differences between the most recent guidelines proposed by the American Association for Study of Liver Diseases and the Asian Pacific Association for the Study of the Liver. Current evidence for the various imaging modalities for diagnosis of HCC and their relevance to the consensus guidelines are reviewed.

Gd-EOB-DTPA-enhanced magnetic resonance images of hepatocellular carcinoma: correlation with histological grading and portal blood flow

OBJECTIVE

To retrospectively investigate enhancement patterns of hepatocellular carcinoma (HCC) and dysplastic nodule (DN) in the hepatobiliary phase of gadolinium-ethoxybenzyl-diethylenetriamine (Gd-EOB-DTPA)-enhanced MRI in relation to histological grading and portal blood flow.

METHODS

Sixty-nine consecutive patients with 83 histologically proven HCCs and DNs were studied. To assess Gd-EOB-DTPA uptake, we calculated the EOB enhancement ratio, which is the ratio of the relative intensity of tumorous lesion to surrounding nontumorous area on hepatobiliary phase images (post-contrast EOB ratio) to that on unenhanced images (pre-contrast EOB ratio). Portal blood flow was evaluated by CT during arterial portography.

RESULTS

Post-contrast EOB ratios significantly decreased as the degree of differentiation declined in DNs (1.00 ± 0.14) and well, moderately and poorly differentiated HCCs (0.79 ± 0.19, 0.60 ± 0.27, 0.49 ± 0.10 respectively). Gd-EOB-DTPA uptake, assessed by EOB enhancement ratios, deceased slightly in DNs and still more in HCCs, while there was no statistical difference in the decrease between different histological grades of HCC. Reductions in portal blood flow were observed less frequently than decreases in Gd-EOB-DTPA uptake in DNs and well-differentiated HCCs.

CONCLUSIONS

Reduced Gd-EOB-DTPA uptake might be an early event of hepatocarcinogenesis, preceding portal blood flow reduction. The hepatobiliary phase of Gd-EOB-DTPA-enhanced MRI may help estimate histological grading, although difficulties exist in differentiating HCCs from DNs.