Unclear focal liver lesions in contrast-enhanced ultrasonography--lessons to be learned from the DEGUM multicenter study for the characterization of liver tumors

Intra-individual comparison of Sonazoid contrast-enhanced ultrasound and SonoVue contrast-enhanced ultrasound in diagnosing hepatocellular carcinoma

PURPOSE

To assess whether the diagnostic performance of Sonazoid contrast-enhanced ultrasound (SZUS) is non-inferior to that of SonoVue contrast-enhanced ultrasound (SVUS) in diagnosing hepatocellular carcinoma (HCC) in individuals with high risk.

MATERIALS AND METHODS

This prospective study was conducted from October 2020 to May 2022 and included participants with a high risk of HCC who underwent SZUS and SVUS. All lesions were confirmed by clinical or pathological diagnosis. Each nodule was classified according to the Contrast-Enhanced Ultrasound Liver Imaging Reporting and Data System version 2017 (CEUS LI-RADS v2017) for SVUS and SZUS and the modified CEUS LI-RADS (using Kupffer phase defect instead of late and mild washout) for SZUS. The diagnostic performance of both two modalities for all observations was compared. Analysis of the vascular phase and Kupffer phase imaging characteristics of CEUS was performed.

RESULTS

One hundred and fifteen focal liver lesions from 113 patients (94 HCCs, 12 non-HCC malignancies, and 9 benign lesions) were analysed. According to CEUS LI-RADS (v2017), SVUS and SZUS showed similar sensitivity (71.3% vs. 72.3%) and specificity (85.7% vs. 81.0%) in HCC diagnosis. However, the modified CEUS LI-RADS did not significantly improve the diagnostic efficacy of Sonazoid compared to CEUS LI-RADS v2017, having equivalent sensitivity (73.4% vs. 72.3%) and specificity (81.0% vs. 81.0%). The agreement between SVUS and SZUS for all observations was 0.610 (95% CI 0.475, 0.745), while for HCCs it was 0.452 (95% CI 0.257, 0.647).

CONCLUSION

Using LI-RADS v2017, SZUS and SVUS showed non-inferior efficacy in evaluating HCC lesions. In addition, adding Kupffer phase defects to SZUS does not notably improve its diagnostic efficacy.

The diagnostic value of Doppler Resistive Index in the differential diagnosis of focal liver lesions

Aim

To investigate the diagnostic value of resistance index (RI) in differentiating focal liver lesions.

Patients and methods

In this retrospective study, a total of 576 patients with histologically confirmed focal liver lesions were included. Each patient underwent B-mode ultrasound examination and color Doppler ultrasound examination. The RI values of different focal liver lesions were recorded and compared.

Results

The mean RI value of benign lesions was significantly lower than that of malignant lesions (0.54 ± 0.10 vs. 0.71 ± 0.12) (p <0.05). In malignant lesions, the RI value of intrahepatic cholangiocarcinoma was significantly lower than that of hepatocellular carcinoma lesions. Furthermore, in hepatocellular carcinoma lesions, the RI of large lesions (group 4: >10 cm) was significantly lower than that of small lesions (group 1: ≤2 cm, group 2: 2-5 cm) (p <0.05). Taken RI of 0.615 as a cutoff value to differentiate malignant and benign lesions, the sensitivity, specificity, positive predictive value and negative predictive value were 82.80%, 81.00%, 81.34% and 82.48%, respectively.

Conclusion

Color Doppler ultrasound examination is a valuable imaging method in detecting blood flow signal within liver lesions. The RI parameter should be helpful in differentiating malignant and benign liver tumors.

Imaging of pediatric liver tumors: A COG Diagnostic Imaging Committee/SPR Oncology Committee White Paper

Primary hepatic malignancies are relatively rare in the pediatric population, accounting for approximately 1%-2% of all pediatric tumors. Hepatoblastoma and hepatocellular carcinoma are the most common primary liver malignancies in children under the age of 5 years and over the age of 10 years, respectively. This paper provides consensus-based imaging recommendations for evaluation of patients with primary hepatic malignancies at diagnosis and follow-up during and after therapy.

Incidental Findings in Pediatric Patients: How to Manage Liver Incidentaloma in Pediatric Patients

The World Federation for Ultrasound in Medicine and Biology (WFUMB) is addressing the issue of incidental findings (IFs) with a series of publications entitled "Incidental imaging findings-the role of ultrasound". IFs in the liver of newborns and children are rare and much less commonly encountered than in adults; as a result, they are relatively much more frequently malignant and life-threatening, even when they are of benign histology. Conventional B-mode ultrasound is the well-established first line imaging modality for the assessment of liver pathology in pediatric patients. US technological advances, resulting in image quality improvement, contrast-enhanced ultrasound (CEUS), liver elastography and quantification tools for steatosis have expanded the use of ultrasound technology in daily practice. The following overview is intended to illustrate incidentally detected liver pathology covering all pediatric ages. It aims to aid the examiner in establishing the final diagnosis. Management of incidentally detected focal liver lesions (FLL) needs to take into account the diagnostic accuracy of each imaging modality, the patient's safety issues (including ionizing radiation and nephrotoxic contrast agents), the delay in diagnosis, the psychological burden on the patient and the cost for the healthcare system. Moreover, this paper should help the pediatric clinician and ultrasound practitioner to decide which pathologies need no further investigation, which ones require interval imaging and which cases require further and immediate diagnostic procedures.

Focal Liver Lesions other than Hepatocellular Carcinoma in Cirrhosis: Diagnostic Challenges

Liver cirrhosis is associated with regenerative nodules and an increased risk of developing hepatocellular carcinoma (HCC). However, other benign and malignant liver lesions may also occur. Differentiating the other lesions from HCC is important for further therapeutic decisions. This review discusses the characteristics of non-HCC liver lesions in cirrhosis and their consequent appearance on contrast-enhanced ultrasonography (CEUS) with consideration of other imaging. Knowledge of this data would be helpful in avoiding misdiagnoses.

Modified contrast-enhanced ultrasonography with the new high-resolution examination technique of high frame rate contrast-enhanced ultrasound (HiFR-CEUS) for characterization of liver lesions: First results

AIM

To examine to what extent the high frame rate contrast-enhanced ultrasound (HiFR) diagnostic enables the conclusive diagnosis of liver changes with suspected malignancy.

MATERIAL/METHODS

Ultrasound examinations were performed by an experienced examiner using a multifrequency probe (SC6-1) on a high-end ultrasound system (Resona 7, Mindray) to clarify liver changes that were unclear on the B-scan. A bolus of 1-2.4 ml of the Sulphur hexafluoride ultrasound microbubbles contrast agent SonoVue™ (Bracco SpA, Italy) was administered with DICOM storage of CEUS examinations from the early arterial phase (5-15 s) to the late phase (5-6 min). Based on the image files stored in the PACS, an independent reading was performed regarding image quality and finding-related diagnostic significance (0 not informative/non-diagnostic to 5 excellent image quality/confident diagnosis possible). References were clinical follow-up, if possible, comparison to promptly performed computed tomography or magnetic resonance imaging, in some cases also to histopathology.

RESULTS

We examined 100 patients (42 women, 58 men, from 18 years to 90 years, mean 63±13 years) with different entities of focal and diffuse liver parenchymal changes, which could be detected in all cases with sufficient image quality with CEUS and with high image quality with HiFR-CEUS. Proportionally septate cysts were found in n = 19 cases, scars after hemihepatectomy with local reduced fat in n = 5 cases, scars after microwave ablation in n = 19 cases, hemangiomas in n = 9 cases, focal nodular hyperplasia in n = 8 cases, colorectal metastases in n = 15 cases, hepatocellular carcinoma (HCC) in n = 11 cases, Osler disease in n = 8 cases. The size of lesions ranged from 5 mm to 200 mm with a mean value of 33.1±27.8 mm. Conclusive diagnoses could be made by the experienced investigator in 97/100 cases with CEUS, confirmed by reference imaging, in parts by histopathology or follow-up. The image quality for HiFR CEUS was rated with a score of 3 to 5; 62 cases were assessed with an average of good (4 points), 27 cases with very good (5 points), and in 11 cases (3 points) still satisfactory despite aggravated acoustic conditions. The specificity of HIFR-CEUS was 97%, the sensitivity 97%, the positive predictive value 94%, the negative predictive value 99% and the accuracy 97%.

CONCLUSION

HIFR-CEUS has demonstrated has demonstrated an improved image quality resulting in a high diagnostic accuracy. In the hands of an experienced investigator, HiFR-CEUS allows the assessment of focal and diffuse unclear liver parenchymal changes on B-scan and dynamic assessment of microcirculation in solid and vascular changes.

When Benign Behaves Badly: Atypical Hemangiomas on Contrast-Enhanced Ultrasonography

ABSTRACT

Hemangioma is the most common benign liver tumor and is frequently encountered as an incidental finding on imaging. The classic enhancement pattern of hemangioma is diagnostic on contrast-enhanced ultrasound (CEUS), and it follows the same pattern of enhancement on computed tomography and magnetic resonance imaging. However, there is a subset of hemangiomas that demonstrate atypical enhancement patterns on CEUS. The ability to recognize the different enhancement patterns and discern when additional imaging or biopsy may be necessary is essential to accurately interpret an atypical hemangioma on CEUS. This article reviews various enhancement patterns of hemangioma on CEUS to avoid pitfalls in characterization of focal liver lesions on CEUS.

Multiparametric Ultrasound Approach Using a Tree-Based Decision Classifier for Inconclusive Focal Liver Lesions Evaluated by Contrast Enhanced Ultrasound

BACKGROUND

Multiparametric ultrasound (MPUS) is a concept whereby the examiner is encouraged to use the latest features of an ultrasound machine. The aim of this study was to reanalyze inconclusive focal liver lesions (FLLs) that had been analyzed via contrast enhanced ultrasound (CEUS) using the MPUS approach with the help of a tree-based decision classifier.

MATERIALS AND METHODS

We retrospectively analyzed FLLs that were inconclusive upon CEUS examination in our department, focusing our attention on samples taken over a period of two years (2017-2018). MPUS reanalysis followed a three-step algorithm, taking into account the liver stiffness measurement (LSM), time-intensity curve analysis (TIC), and parametric imaging (PI). After processing all steps of the algorithm, a binary decision tree classifier (BDTC) was used to achieve a software-assisted decision.

RESULTS

Area was the only TIC-CEUS parameter that showed a significant difference between malign and benign lesions with a cutoff of >-19.3 dB for washout phenomena (AUROC = 0.58, Se = 74.0%, Sp = 45.7%). Using the binary decision tree classifier (BDTC) algorithm, we correctly classified 71 out of 91 lesions according to their malignant or benignant status, with an accuracy of 78.0% (sensitivity = 62%, specificity = 45%, and precision = 80%).

CONCLUSIONS

By reevaluating inconclusive FLLs that had been analyzed via CEUS using MPUS, we managed to determine that 78% of the lesions were malignant and, in 28% of them, we established the lesion type.

Contrast-enhanced ultrasonography for the evaluation of malignant focal liver lesions

In this review, the authors address the analysis of different types of malignant focal liver lesions (FLLs) using contrast-enhanced ultrasonography (CEUS). The specific enhancing patterns of hepatocellular carcinoma, cholangiocarcinoma, and metastases are discussed and exemplified with images. In addition, the use of CEUS in malignant portal vein thrombosis is discussed. The advantages and limitations of CEUS for the analysis of malignant FLLs are also discussed.

Current Opinion about Hepatocellular Carcinoma <10 mm

BACKGROUND

Early detection of hepatocellular carcinoma (HCC) is important. Advances in liver imaging techniques have facilitated the detection of HCC at an early stage. However, there is a controversial discussion on how to diagnose very small HCC by imaging. The aim of the current review is to present current published data on HCC ≤10 mm and discuss on how to best diagnose and treat such lesions.

SUMMARY

It is still challenging, however, to accurately characterize HCC <10 mm. The accuracy of contrast-enhanced ultrasound may be critical for early treatment decisions for cancer patients, particularly when CECT and/or CEMRI are inconclusive. Key Messages: The characterization of focal liver lesions <10 mm is frequently delayed until a follow-up imaging procedure demonstrates growth or stability. A repetition of ultrasound examination after 3 months for new nodules <1 cm should be recommended.

Quantitative Analysis of the Time-Intensity Curve of Contrast-Enhanced Ultrasound of the Liver: Differentiation of Benign and Malignant Liver Lesions

Background: To evaluate the diagnostic accuracy of quantitative perfusion parameters in contrast-enhanced ultrasound to differentiate malignant from benign liver lesions. Methods: In this retrospective study 134 patients with a total of 139 focal liver lesions were included who underwent contrast enhanced ultrasound (CEUS) between 2008 and 2018. All examinations were performed by a single radiologist with more than 15 years of experience using a second-generation blood pool contrast agent. The standard of reference was histopathology (n = 60), MRI or CT (n = 75) or long-term CEUS follow up (n = 4). For post processing regions of interests were drawn both inside of target lesions and the liver background. Time–intensity curves were fitted to the CEUS DICOM dataset and the rise time (RT) of contrast enhancement until peak enhancement, and a late-phase ratio (LPR) of signal intensities within the lesion and the background tissue, were calculated and compared between malignant and benign liver lesion using Student’s t-test. Quantitative parameters were evaluated with respect to their diagnostic accuracy using receiver operator characteristic curves. Both features were then combined in a logistic regression model and the cumulated accuracy was assessed. Results: RT of benign lesions (14.8 ± 13.8 s, p = 0.005), and in a subgroup analysis, particular hemangiomas (23.4 ± 16.2 s, p < 0.001) differed significantly to malignant lesions (9.3 ± 3.8 s). The LPR was significantly different between benign (1.59 ± 1.59, p < 0.001) and malignant lesions (0.38 ± 0.23). Logistic regression analysis with RT and LPR combined showed a high diagnostic accuracy of quantitative CEUS parameters with areas under the curve of 0.923 (benign vs. malignant) and 0.929 (hemangioma vs. malignant. Conclusions: Quantified CEUS parameters are helpful to differentiate malignant from benign liver lesions, in particular in case of atypical hemangiomas.

Diagnostic value of contrast-enhanced ultrasound versus computed tomography for hepatocellular carcinoma: a retrospective, single-center evaluation of 234 patients

OBJECTIVE

Hepatocellular carcinoma (HCC) is the most common cause of primary liver cancer. A major part of diagnostic HCC work-up is based on imaging findings from sonography, computed tomography (CT), or magnetic resonance imaging (MRI) scans. Contrast-enhanced ultrasound (CEUS) allows for the dynamic assessment of the microperfusion pattern of suspicious liver lesions. This study aimed to evaluate the diagnostic value of CEUS compared with CT scans for assessing HCC.

METHODS

We performed a retrospective, single-center study between 2004 and 2018 on 234 patients with suspicious liver lesions who underwent CEUS and CT examinations. All patients underwent native B-mode, color Doppler and CEUS after providing informed consent. Every CEUS examination was performed and interpreted by a single experienced radiologist (European Federation of Societies for Ultrasound in Medicine and Biology level 3).

RESULTS

CEUS was performed on all included patients without occurrence of any adverse effects. CEUS showed a sensitivity of 94%, a specificity of 70%, a positive predictive value of 93% and a negative predictive value of 72% for analyzing HCC compared with CT as the diagnostic gold standard.

CONCLUSIONS

CEUS has an excellent safety profile and shows a high diagnostic accuracy in assessing HCC compared with corresponding results from CT scans.

[Current state of research in abdominal ultrasonography at German university hospitals. A panel study over 20 years]

BACKGROUND

 The state of research in the field of abdominal ultrasonography has been deficient for years at German university hospitals. Neither research activity nor funding are appropriate given the actual clinical importance of this method.

OBJECTIVE

 In analogy to studies conducted in 1999 and 2009, this study aims to provide a survey into the state of research in the field of abdominal ultrasonography at German university hospitals. It focuses on the topics of research activity, research funding, publication rate and the development of structural conditions.

METHODS

 Chief gastroenterologists from Germany's 34 university hospitals were invited to respond to a postal survey asking about the aforementioned topics. We asked them to forward the survey in case somebody else was responsible for the respective tasks. The response rate was 79 %.

RESULTS

 The amount of hospitals doing research has roughly remained the same with 77 % compared to 74 % in 2009 and 80 % in 1999. On average, however, there are less research projects per department with 3.2 at the moment compared to 3.5 in 1999 and 3.6 in 2009, and research funding has continued to worsen. 75 % of the heads of departments state that they have not received any funding in addition to the usual budget. Funding by producers of ultrasound machines has also reached a low with 11 % compared to 45 % in 2009 and 31 % in 1999. Only public and university funding show a positive trend. The Deutsche Forschungsgemeinschaft (German Research Foundation) is currently not funding any research projects in the field of abdominal ultrasonography. 13 university hospitals provided information about their publication rate in 1999, 2009 and 2019. Whereas the rate had generally remained constant in the previous studies, the annual number of publications has continually increased in the current survey period. 75 % of the publications came from university hospitals that have established or are currently planning to establish interdisciplinary ultrasound centers. The previous studies also showed that more and more hospitals publish in English instead of German. This trend continues. During the survey period, 60 % of publications were both in English and German, 37 % in English and only 3 % exclusively in German. Most publications dealt with clinical and only a few technical or basic research questions. This was also the case in the previous studies. There have been less publications on the use of ultrasound contrast agents in the present survey period. There is also a decline in the number of systematic reviews. Similar to 2009, the impact factor of journals devoted to sonography is increasing and it is growing stronger than that of journals dedicated to radiology. However, only 29 % of the heads of departments agreed that ultrasonography was a field of research that improves your career prospects.

CONCLUSIONS

 The present study did not show a significant improvement of research activity in the field of abdominal ultrasonography. However, an increased publication rate indicates a trend towards high-performing research centers. Research funding remains deficient and has worsened in the past 20 years. The demands made by the previous studies for research funding appropriate to the importance of this clinical method remain.

The diagnostic performance of contrast-enhanced ultrasound (CEUS) for evaluating hepatocellular carcinoma (HCC) juxtaposed to MRI findings; a retrospective single-center analysis of 292 patients

BACKGROUND

HCC is the most frequent primary liver cancer entity. Major risk factors comprise chronic HBC and HCV infections, ALD or NAFLD. Apart from the anamnesis, the clinical examination and serologic analysis, an essential part of the diagnostic HCC work-up is due to imaging findings from sonography, CT or MRI scans. HCC lesions feature a distinct vascularization pattern: hyperenhancement during early arterial and hypoenhancement/wash-out during portal venous or delayed phases. CEUS facilitates dynamic assessment of microperfusion patterns of suspicious liver lesions.

PURPOSE

The purpose of the present retrospective single-center study was to determine the diagnostic value of CEUS for assessing HCC by comparison with findings from MRI scans.

MATERIALS AND METHODS

Between 2004-2018 292 patients with suspicious liver lesions underwent CEUS and MRI. All patients underwent native B-mode, Color Doppler and CEUS after given informed consent. The applied contrast agent was a second-generation blood pool agent (SonoVue®, Bracco, Milan, Italy). Every CEUS examination was performed and interpreted by a single experienced radiologist (EFSUMB Level 3).

RESULTS

CEUS was performed on all included patients without occurrence of any adverse effects. CEUS showed a sensitivity of 96%, a specificity of 91%, a PPV of 95% and a NPV of 94% for analyzing HCC in comparison with MRI as the diagnostic gold standard.

CONCLUSION

With a distinguished safety profile CEUS shows a high diagnostic accuracy in assessing HCC compared to corresponding results from MRI scans.

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.

Usefulness of the Contrast-Enhanced Ultrasound Liver Imaging Reporting and Data System in Diagnosing Focal Liver Lesions by Inexperienced Radiologists

OBJECTIVES

To evaluate the usefulness of the contrast-enhanced ultrasound (CEUS) Liver Imaging Reporting and Data System (LI-RADS) in diagnosing focal liver lesions (FLLs) by inexperienced radiologists.

METHODS

Images and clinical data from 258 patients at risk for hepatocellular carcinoma who underwent CEUS were collected retrospectively. Two trained inexperienced radiologists and 2 experienced radiologists reviewed all CEUS clips. Each inexperienced radiologist assigned a CEUS LI-RADS category for each observation and labeled it benign or malignant independently. Each experienced radiologist labeled each lesion malignant or benign independently using a conventional diagnostic method. Interobserver agreement of CEUS LI-RADS was analyzed by the κ test. The overall diagnostic accuracy of the LI-RADS category and conventional diagnosis was described by the sensitivity, specificity, positive predictive value, and negative predictive value. All test results were considered significant at P < .05.

RESULTS

A κ value of 0.774 indicated that the CEUS LI-RADS algorithm resulted in substantial consistency between the inexperienced radiologists. For the diagnosis of hepatocellular carcinoma, the sensitivity, specificity, positive predictive value, and negative predictive value were improved significantly in inexperienced radiologists using the CEUS LI-RADS compared to conventional methods. The overall diagnostic accuracy of the experienced radiologists was almost equal to that of CEUS LI-RADS categories assigned by the inexperienced radiologists.

CONCLUSIONS

The CEUS LI-RADS algorithm can not only obtain substantial consistency among inexperienced radiologists but also have excellent diagnostic efficacy in the differentiation of benign from malignant FLLs compared to conventional methods. As a comprehensive algorithm, the CEUS LI-RADS can act as a guide for trainees in learning how to diagnose FLLs.

Limited added value of contrast-enhanced ultrasound over B-mode for the subtyping of hepatocellular adenomas

PURPOSE

To compare the features of hepatocellular adenoma subtypes (HCAs) in B-mode and contrast-enhanced ultrasound (CEUS).

METHOD

Thirty-three patients (31 women [94 %] and two men [6%], median age [Q1-Q3] 43.5 years old [35-51]) with 44 pathologically proven and subtyped HCAs (including 29 inflammatory HCAs [I-HCA] and 15 HNF1-α inactivated HCAs [H-HCA]) who underwent CEUS were included. The features of HCA on B-mode and CEUS were independently reviewed by two radiologists and compared between HCA subtypes.

RESULTS

I-HCAs were mostly hypoechoic (23/29, 79 %) or isoechoic (4/29, 14 %) with B-mode. Twelve of them (41 %) were heterogeneous. All H-HCAs except one demonstrated homogeneous hyperechogenicity (93 %) (p = 0.001). Moderate or marked liver steatosis was only observed in I-HCAs (12/29, 41 %) (p = 0.001). Arterial hyperenhancement was observed on CEUS in 27/29 (93 %) I-HCAs and in 14/15 (93 %) H-HCAs (p=0.98). Washout was present in 6/29 (21 %) I-HCAs and 1/15 (7%) H-HCAs (p=0.27). A total of 23/29 (79 %) I-HCAs and 15/15 (100 %) HCAs were homogeneous on portal and delayed phase acquisitions (p=0.04). The specificity for identifying an H-HCA was 100 % when the lesion was homogeneous and hyperechoic on B-mode, and the sensibility to rule out an H-HCA was 100 % if neither of these two features was present in a liver with obvious steatosis.

CONCLUSIONS

Most CEUS features, especially enhancement patterns, do not significantly differ between HCA subtypes. When HCA is suspected on CEUS, B-mode features should be considered, and a combination of lesion hyperechogenicity, homogeneity and the absence of obvious liver steatosis may be useful to distinguish H-HCAs from I-HCAs.

[Sonographic diagnostics of liver tumors]

Liver tumors are often incidentally found during ultrasound examinations. The decision on further diagnostic imaging depends on the clinical context and the appearance in B mode ultrasound. This review highlights the role of grey scale and contrast-enhanced ultrasound (CEUS) and summarizes the ultrasonographic key features of the most common benign and malignant liver tumors. Conventional grey scale ultrasound is recommended in several guidelines for screening and follow-up of liver tumors in certain risk populations but its ability to characterize liver tumors is limited in most cases. The CEUS has an excellent tolerability and enables liver tumor characterization with a high sensitivity and specificity. The diagnostic value of CEUS is comparable to magnetic resonance imaging. In the case of unclear lesions, inconclusive findings by different imaging methods or if molecular targeted treatment is pursued, ultrasound-guided biopsy is often mandatory. Ultrasound is a rapidly and ubiquitously available method for the detection of liver tumors and CEUS is the only imaging method that enables real-time examination of all contrast phases in the liver. It should therefore be used as the first line imaging method for liver tumor characterization.

Influence of Data Parsing on Contrast Enhanced Ultrasound Exams

RATIONALE AND OBJECTIVES

To explore the influence of data parsing (either selection of frames at set time intervals or by an experienced sonographer) of contrast-enhanced ultrasound (CEUS) exams on physician diagnoses and confidence levels.

MATERIALS AND METHODS

Forty consecutive CEUS exams consisting of 10 cases each of indeterminate liver lesions, indeterminate renal lesions, renal cell carcinoma postablation follow-up, and hepatocellular carcinoma postchemoembolization follow-up were selected for analysis. Exams were parsed into sets consisting of five images selected by the performing sonographer and sets containing systematically stored frames every 10, 30, and 60 seconds. Three blinded physicians then reviewed the cine loop and each set of images in randomized order and provided a diagnosis and confidence level.

RESULTS

For all clinical applications investigated, no statistically significant differences in diagnostic performance measures or reader confidence were observed between review of the entire cine loop and images selected by the performing sonographer (p > 0.42). Diagnostic performance at 10-second intervals did not show statically significant changes compared to the full cine loop review for all applications (p > 0.18), although reader confidence decreased. At 30-60-second intervals, both diagnostic performance and reader confidence showed statistically significant reduction compared to review of the full cine loop (p < 0.045).

CONCLUSIONS

Transfer and review of large cine loops from CEUS exams represent a potential barrier to adoption within the United States workflows. This study demonstrates that images selected by a performing trained sonographer may provide the same value without the review time and data storage costs needed for full cine loop review. Parsing by time points reduced reader confidence and diagnostic performance.

[Contrast-enhanced ultrasound (CEUS) and image fusion for procedures of liver interventions]

CLINICAL/METHODICAL ISSUE

Contrast-enhanced ultrasound (CEUS) is becoming increasingly important for the detection and characterization of malignant liver lesions and allows percutaneous treatment when surgery is not possible. Contrast-enhanced ultrasound image fusion with computed tomography (CT) and magnetic resonance imaging (MRI) opens up further options for the targeted investigation of a modified tumor treatment.

METHODICAL INNOVATIONS

Ultrasound image fusion offers the potential for real-time imaging and can be combined with other cross-sectional imaging techniques as well as CEUS.

PERFORMANCE

With the implementation of ultrasound contrast agents and image fusion, ultrasound has been improved in the detection and characterization of liver lesions in comparison to other cross-sectional imaging techniques. In addition, this method can also be used for intervention procedures. The success rate of fusion-guided biopsies or CEUS-guided tumor ablation lies between 80 and 100% in the literature.

ACHIEVEMENTS

Ultrasound-guided image fusion using CT or MRI data, in combination with CEUS, can facilitate diagnosis and therapy follow-up after liver interventions.

PRACTICAL RECOMMENDATIONS

In addition to the primary applications of image fusion in the diagnosis and treatment of liver lesions, further useful indications can be integrated into daily work. These include, for example, intraoperative and vascular applications as well applications in other organ systems.

SIUMB guidelines and recommendations for the correct use of ultrasound in the management of patients with focal liver disease

The present document describes the SIUMB (Italian Society of Ultrasound in Medicine and Biology) guidelines for the use of ultrasound in the management of focal liver disease. The aim of the paper is to provide a clinical practice guideline for Italian physicians who are approaching the ultrasound study of a focal liver lesion. In particular, these guidelines provide simple indications, recommendations and general practice advices for the correct use of contrast-enhanced ultrasound (CEUS) in this scenario. They represent the SIUMB position of the ultrasound role in the diagnostic flow charts of the principal focal liver lesions, and are in agreement with other, previously published national and international guidelines.

Atypical appearance of hepatic hemangiomas with contrast-enhanced ultrasound

To describe the atypical enhancement pattern of hepatic hemangiomas on contrast-enhanced sonography. 22 patients with hepatic hemangiomas that were atypical on contrast-enhanced ultrasound were included in the study, all of them were confirmd by biopsy or surgery pathology. Atypical appearance of hepatic hemangiomas on contrast-enhanced ultrasound were divided into seven subtypes: (i) peripheral nodular enhancement in the arterial phase with centripedal filling, hypoechoic change in the delayed phase; (ii) peripheral circular enhancement; (iii) peripheral nodular enhancement; (iv) none enhancement; (v) septal enhancement; (vi) a central enhancing focus in the arterial phase, followed by a centrifugal enhancement in the portal venous phase, hypoechoic change in the delayed phase; (vii) slowly spoke wheel enhancement. Atypical appearance of hepatic hemangiomas were various. Radiologists should be aware. Establishing knowledge of the entire spectrum of atypical hepatic hemangiomas may benefit the rational approach to future cases.

How to perform Contrast-Enhanced Ultrasound (CEUS)

"How to perform contrast-enhanced ultrasound (CEUS)" provides general advice on the use of ultrasound contrast agents (UCAs) for clinical decision-making and reviews technical parameters for optimal CEUS performance. CEUS techniques vary between centers, therefore, experts from EFSUMB, WFUMB and from the CEUS LI-RADS working group created a discussion forum to standardize the CEUS examination technique according to published evidence and best personal experience. The goal is to standardise the use and administration of UCAs to facilitate correct diagnoses and ultimately to improve the management and outcomes of patients.

A Model-Based Prediction of the Probability of Hepatocellular Adenoma and Focal Nodular Hyperplasia Based on Characteristics on Contrast-Enhanced Ultrasound

Contrast-enhanced ultrasound (CEUS) is an emerging imaging technique that is increasingly used to diagnose liver lesions. It is of the utmost importance to differentiate between the two most common solid focal liver lesions (i.e., hepatocellular adenoma [HCA] and focal nodular hyperplasia [FNH]), because their management and follow-up differ greatly. The main objective of this study was to determine how frequently the specific CEUS features of HCA and FNH are visible on CEUS and to define their predictive value for discrimination between HCA and FNH. We included 324 CEUS examinations performed on patients with FNH (n = 181) or HCA (n = 143). Patients with HCA and FNH significantly differed with respect to age and CEUS features of steatosis, echogenicity, homogeneity, the presence of a central scar, central artery, arterial enhancement pattern, necrosis or thrombus and enhancement in the late venous phase.

Intrasurgical dignity assessment of hepatic tumors using semi-quantitative strain elastography and contrast-enhanced ultrasound for optimisation of liver tumor surgery

OBJECTIVE

To evaluate the efficacy of strain elastography (SE) using semi-quantitative measurement methods compared to constrast enhanced ultrasound during liver tumor surgery (Io-CEUS) for dignity assessment of focal liver lesions(FLL).

MATERIAL AND METHODS

Prospective data acquisition and retrospective analysis of US data of 100 patients (116 lesions) who underwent liver tumor surgery between 10/2010 and 03/2016. Retrospective reading of SE color patterns was performed establishing groups depending on dominant color (>50% blue = stiff, inhomogenous, >50% yellow/red/green = soft tissue). Semi-quantitative analysis was performed by Q-analysis based on a scale from 0 (soft) to 6 (stiff). 2 ROIs were placed centrally, 5 ROIs in the lesion's surrounding tissue. Io-CEUS was performed by bolus injection of 5-10 ml sulphurhexaflourid microbubbles evaluating wash-in- and -out- kinetics in arterial, portal venous and late phase. Histopathology after surgical resection served as goldstandard.

RESULTS

100 patients (m: 65, f: 35, mean age 60.5 years) with 116 liver lesions were included. Lesion's size ranged from 0.5 to 8.4 cm (mean 2.42 cm SD±1.44 cm). Postoperative histology showed 105 malignant and 11 benign lesions. Semi-quantitative analysis showed central indurations of >2.5 in 76/105 cases suggesting malignancy. 7 benign lesions displayed no central indurations correctly characterized benign by SE. ROC-analysis and Youden index showed a sensitivity of 72.4% and specificity of 63.6% assuming a cut-off of 2.5. Io-CEUS correctly characterized 103/105 as malignant. Sensitivity was 98%, specificity 72.7%.

CONCLUSION

Strain elastography is a valuable tool for non-invasive characterization of FLLs. Semi-quantitative intratumoral stiffness values of >2.5 suggested malignancy. However, sensitivity of Io-CEUS in detecting malignant lesions was higher compared to SE. In conclusion SE should be considered for routine use during intraoperative US in addition to Io-CEUS for optimization of curative liver surgery.

Contrast-enhanced ultrasound features of histologically proven small (≤20 mm) liver metastases

OBJECTIVE

We analyzed contrast-enhanced ultrasound (CEUS) features of histologically proved small (≤20 mm) liver metastases, in comparison to small (≤20 mm) hepatocellular carcinomas (HCC), to define the differentiate diagnoses value of CEUS in clinical practice.

MATERIAL AND METHODS

Eighty-two cases of small (≤20 mm) liver metastases and 84 cases of small (≤20 mm) HCC were retrospectively reviewed. All patients had CEUS images. Two radiologists assessed CEUS enhancement pattern and time of enhancement in consensus. Statistical analyses were performed using SPSS v.19.0 (SPSS Inc., Chicago, IL). The χ² test and the independent sample t-test were used to compare the differences.

RESULTS

Comparing to small HCCs, rapid rim-like hyper-enhancement in arterial phase (56.1% in liver metastases vs. 2.3% in HCCs, p < .01), rapid wash-out and become hypo-enhancement in late arterial phase or early portal venous phase (96.4% in liver metastases vs. 22.6% in HCCs, p < .01) with central non-enhanced area in late phase were characteristic CEUS features of small metastases.

CONCLUSIONS

CEUS imaging enhancement findings reliably offer typical signs of small liver metastases, differentiate effectively with small HCCs. CEUS can help to improve the diagnostic confidence of small liver metastases.

Contrast-enhanced ultrasound of histologically proven hepatic epithelioid hemangioendothelioma

AIM: To analyze contrast-enhanced ultrasound (CEUS) features of histologically proven hepatic epithelioid hemangioendothelioma (HEHE) in comparison to other multilocular benign focal liver lesions (FLL).

METHODS: Twenty-five patients with histologically proven HEHE and 45 patients with histologically proven multilocular benign FLL were retrospectively reviewed. Four radiologists assessed the CEUS enhancement pattern in consensus.

RESULTS: HEHE manifested as a single (n = 3) or multinodular (n = 22) FLL. On CEUS, HEHE showed rim-like (18/25, 72%) or heterogeneous hyperenhancement (7/25, 28%) in the arterial phase and hypoenhancement (25/25, 100%) in the portal venous and late phases (PVLP), a sign of malignancy. Eighteen patients showed central unenhanced areas (18/25, 72%); in seven patients (7/25, 28%), more lesions were detected in the PVLP. In contrast, all patients with hemangioma and focal nodular hyperplasia showed hyperenhancement as the most distinctive feature (P < 0.01).

CONCLUSION: CEUS allows for characterization of unequivocal FLL. By analyzing the hypoenhancement in the PVLP, CEUS can determine the malignant nature of HEHE.

International guidelines for contrast-enhanced ultrasonography: ultrasound imaging in the new millennium

The intent of this review is to discuss and comment on common clinical scenarios in which contrast-enhanced ultrasonography (CEUS) may play a decisive role and to illustrate important points with typical cases. With the advent of CEUS, the scope of indications for ultrasonography has been dramatically extended, and now includes functional imaging and tissue characterization, which in many cases enable tumor diagnosis without a biopsy. It is virtually impossible to imagine the practice of modern medicine as we know it in high-income countries without the use of imaging, and yet, an estimated two thirds of the global population may receive no such care. Ultrasound imaging with CEUS has the potential to correct this inequity.

[Ultrasound elastography]

Noninvasive, ultrasound-based methods for visualizing and measuring tissue elasticity are becoming more and more common in routine practice. Using hepatic shear wave elastography, cut-off levels can help to detect the degree of relevant fibrosis (F ≥ 2) with a diagnostic accuracy using the area under the reader operating characteristic (AUROC) of 87 % and cirrhosis (F = 4, AUROC 93 %). Normal values virtually exclude liver cirrhosis (negative predictive value up to 97 %) and high shear wave velocities predict complications in the course of primary sclerosing cholangitis, liver cirrhosis and chronic hepatitis B or C. Elastography is of no relevant help in the differentiation of the dignity of hepatic lesions. Concerning thyroid or breast lesions, low shear wave velocities are indicative of benign lesions and in contrast, high velocities of malignant lesions. A differentiation between benign and malignant thyroid nodules is performed by elastography with a sensitivity of 89 % and a specificity of 82 %. In breast lesions a differentiation of nodes can be improved with elastography compared to B-mode ultrasound alone with a sensitivity of 97 % and a specificity of 83 %. Invasive biopsy punctures can therefore be specifically performed or can be omitted. Due to several influencing factors, in particular during liver elastography, the measurements need to be interpreted in the clinical context. In summary, ultrasound-based elastography provides helpful information for the detection of hepatic fibrosis and for further characterization of thyroid or breast lesions in addition to classical techniques, such as B-mode imaging and color Doppler.

A new automated quantification algorithm for the detection and evaluation of focal liver lesions with contrast-enhanced ultrasound

PURPOSE

Detect and classify focal liver lesions (FLLs) from contrast-enhanced ultrasound (CEUS) imaging by means of an automated quantification algorithm.

METHODS

The proposed algorithm employs a sophisticated segmentation method to detect and contour focal lesions from 52 CEUS video sequences (30 benign and 22 malignant). Lesion detection involves wavelet transform zero crossings utilization as an initialization step to the Markov random field model toward the lesion contour extraction. After FLL detection across frames, time intensity curve (TIC) is computed which provides the contrast agents' behavior at all vascular phases with respect to adjacent parenchyma for each patient. From each TIC, eight features were automatically calculated and employed into the support vector machines (SVMs) classification algorithm in the design of the image analysis model.

RESULTS

With regard to FLLs detection accuracy, all lesions detected had an average overlap value of 0.89 ± 0.16 with manual segmentations for all CEUS frame-subsets included in the study. Highest classification accuracy from the SVM model was 90.3%, misdiagnosing three benign and two malignant FLLs with sensitivity and specificity values of 93.1% and 86.9%, respectively.

CONCLUSIONS

The proposed quantification system that employs FLLs detection and classification algorithms may be of value to physicians as a second opinion tool for avoiding unnecessary invasive procedures.

Gray scale and contrast-enhanced ultrasound imaging of malignant liver tumors of vascular origin

OBJECTIVES

Malignant vascular tumors of the liver are rare. The aim of this study was to investigate the applicability of gray scale and contrast-enhanced ultrasonography in patients with epithelioid hemangioendothelioma (EHE) of the liver and hepatic angiosarcoma (HA) and to describe the clinical presentation.

METHODS

We retrospectively analyzed all patients with epithelioid hemangioendothelioma or hemangiosarcoma of the liver from 1998 to 2011, who underwent ultrasound investigation. We describe the findings in gray scale and contrast-enhanced ultrasound and the clinical course of the disease of seven patients with EHE and five patients with HA.

RESULTS

Ultrasound investigation in EHE showed mostly multiple hypoechoic irregular lesions close to the liver capsule and with a halo in some cases. Contrast enhancement revealed inhomogeneously and through all contrast phases vascularized tumors with a rim enhancement in 50%, with or without early wash out. All tumors had avascular parts. HA presented as multiple and irregular hypo-, iso- or hyperechoic lesions. After contrast enhancement, hypervascularization with individual patterns was evident in all patients. Of five, three had liquid parts. Patients with HA were significantly older (58 vs. 37 years, p = 0.014) and presented with lower thrombocyte counts (84 vs. 264, p = 0.0025) and with higher CEA levels (4.6 vs. 1.5, p = 0.03).

CONCLUSION

EHE and HA are inhomogeneous tumors, explaining the high inter-individual variability and heterogeneity in ultrasound examination. The presence of multifocal lesions, heterogeneity and undefined margins may differentiate EHE or HA from hemangioma. A biopsy is essential in the diagnosis of vascular tumors.

Contrast-enhanced ultrasound of focal nodular hyperplasia: a matter of size

OBJECTIVES

To assess the contrast-enhanced ultrasound (CEUS) frequencies of centrifugal enhancement, spoke-wheel sign and central scar in focal nodular hyperplasia (FNH) as a function of lesion size.

METHODS

Ninety-four FNHs were retrospectively reviewed to assess their largest diameter and enhancement pattern, including centrifugal enhancement from one central artery, spoke-wheel sign, diffuse or centripetal enhancement, central scar and late-phase washout.

RESULTS

Mean FNH-lesion size was 3.7 ± 2.1 cm. Only 43.6 % of FNHs had centrifugal enhancement, with a spoke-wheel pattern (23.4 %) or without (20.2 %), while 56.4 % showed diffuse or centripetal enhancement. Centrifugal enhancement was observed in 73.9 % of FNHs ≤3.1 cm and 14.6 % of FNHs >3.1 cm (P < 10(-4)). Size and frequency of centrifugal enhancement were negatively correlated (r = -0.57, P < 10(-4)). The spoke-wheel pattern was also seen more frequently in smaller (37 %) than in larger FNHs (10.4 %) (P < 10(-3)). Late-phase washout was described in 5.3 % of FNHs and was not size-dependent. Lesions with a central scar were larger than those without, respectively, 5.7 ± 1.7 and 3.6 ± 2.0 cm (P = 0.012).

CONCLUSIONS

Typical centrifugal enhancement yielding a confident FNH diagnosis is seen significantly more frequently when the lesion is ≤3.1 cm.

KEY POINTS

• CEUS yields confident diagnoses of FNHs ≤3.1 cm • The larger the FNH, the lower the diagnostic sensitivity of CEUS • Final diagnosis of FNHs >3.1 cm should be obtained with MRI not CEUS.

Indeterminate solid hepatic lesions identified on non-diagnostic contrast-enhanced computed tomography: assessment of the additional diagnostic value of contrast-enhanced ultrasound in the non-cirrhotic liver

OBJECTIVE

To assess the additional diagnostic value of contrast-enhanced ultrasound (CEUS) in the characterization of indeterminate solid hepatic lesions identified on non-diagnostic contrast-enhanced computed tomography (CT).

METHODS

Fifty-five solid hepatic lesions (1-4 cm in diameter) in 46 non-cirrhotic patients (26 female, 20 male; age±SD, 55±10 years) underwent CEUS after being detected on contrast-enhanced CT which was considered as non-diagnostic after on-site analysis. Two blinded independent readers assessed CT and CEUS scans and were asked to classify retrospectively each lesion as a malignant or benign based on reference diagnostic criteria for the different hepatic lesion histotypes. Diagnostic accuracy and confidence (area--Az--under ROC curve) were assessed by using gadobenate dimeglumine-enhanced magnetic resonance (MR) imaging (n=30 lesions), histology (n=7 lesions), or US follow-up (n=18 lesions) as the reference standards.

RESULTS

Final diagnoses included 29 hemangiomas, 3 focal nodular hyperplasias, 1 hepatocellular adenoma, and 22 metastases. The additional review of CEUS after CT images improved significantly (P<.05) the diagnostic accuracy (before vs after CEUS review=49% [20/55] vs 89% [49/55]--reader 1 and 43% [24/55] vs 92% [51/55]--reader 2) and confidence (Az, 95% Confidence Intervals before vs after CEUS review=.773 [.652-.895] vs .997 [.987-1]--reader 1 and .831 [.724-.938] vs .998 [.992-1]--reader 2).

CONCLUSIONS

CEUS improved the characterization of indeterminate solid hepatic lesions identified on non-diagnostic contrast-enhanced CT by identifying some specific contrast enhancement patterns.

Liver unidentified bright object in a septic patient

The typical sonographic appearance of liver hemangiomas is a well-demarcated hyperechoic mass with homogeneous echodensity. Focal liver lesions may change their ultrasound characteristics over time. We present a case of dynamic pattern of liver hemangiomas during a state of systemic inflammation.

Contrast-enhanced sonography in the diagnosis of hepatic hemangiomas: atypical appearance due to the washout of microbubbles

Contrast-enhanced sonography (CEUS) examination permits identification of hemangioma of the liver in most cases. This method is particularly useful when the ultrasound pattern is atypical on standard grayscale examination. CEUS appearances suggestive of hemangioma are peripheral globular enhancement, progression of enhancement toward the center of the nodule, and persistence of enhancement in the late phase. We present seven cases of hemangioma, which were atypical on CEUS examination due to washout during the portal and late phases, resulting in a hypoenhanced appearance compared with the adjacent liver parenchyma.

Fortuitously discovered liver lesions

The fortuitously discovered liver lesion is a common problem. Consensus might be expected in terms of its work-up, and yet there is none. This stems in part from the fact that there is no preventive campaign involving the early detection of liver tumors other than for patients with known liver cirrhosis and oncological patients. The work-up (detection and differential diagnosis) of liver tumors comprises theoretical considerations, history, physical examination, laboratory tests, standard ultrasound, Doppler ultrasound techniques, contrast-enhanced ultrasound (CEUS), computed tomography and magnetic resonance imaging, as well as image-guided biopsy. CEUS techniques have proved to be the most pertinent method; these techniques became part of the clinical routine about 10 years ago in Europe and Asia and are used for a variety of indications in daily clinical practice. CEUS is in many cases the first and also decisive technical intervention for detecting and characterizing liver tumors. This development is reflected in many CEUS guidelines, e.g., in the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) guidelines 2004, 2008 and 2012 as well as the recently published World Federation for Ultrasound in Medicine and Biology-EFSUMB guidelines 2012. This article sets out considerations for making a structured work-up of incidental liver tumors feasible.

Contrast-Enhanced Ultrasound for the differentiation of benign and malignant focal liver lesions: a meta-analysis

BACKGROUND

International guidelines of Ultrasound recommend the performance of contrast-enhanced ultrasound (CEUS) as the first method of choice after conventional ultrasound for the diagnostic work-up of focal liver lesions. However, these recommendations are based on the results of multiple single studies and only few large multicentre studies.

AIMS

The rationale of the present systematic review and meta-analysis was to assess the overall sensitivity and specificity of CEUS for the diagnosis of malignant liver lesions.

METHODS

Literature databases were searched up to March 2012. Inclusion criteria were evaluation of CEUS, assessment of sensitivity and specificity of CEUS for the diagnosis of malignant liver lesions. The meta-analysis was performed using the random-effects model based on the DerSimonian Laird method. Quality analyses were carried out to assess sources of heterogeneity.

RESULTS

A total of 45 studies with 8147 focal liver lesions were included in the analysis. Overall sensitivity and specificity of CEUS for the diagnosis of malignant liver lesions was 93% (95%-CI: 91-95%) and 90% (95%-CI: 88-92%) respectively. Significant heterogeneity was found between studies. However, subanalysis revealed no significant difference when evaluating studies using histology for all liver lesions, when comparing high-quality and low-quality studies, and blinded vs non-blinded studies.

CONCLUSION

The results of this meta-analysis support the international recommendations on CEUS for the diagnostic work-up of focal liver lesions selecting patients who need further diagnostics.

Role of contrast-enhanced ultrasonography in percutaneous radiofrequency ablation of liver metastases and efficacy evaluation

OBJECTIVE

To retrospectively investigate the role of contrast-enhanced ultrasonography (CEUS) in percutaneous radiofrequency ablation (RFA) in patients with liver metastases and evaluate the therapeutic efficacy of RFA assisted by CEUS.

METHODS

From May 2004 to September 2010, 136 patients with 219 liver metastatic lesions received CEUS examination 1 h before RFA (CEUS group), and other 126 patients with 216 lesions without CEUS examination in the earlier period were served as a historical control group. The mean tumor size was 3.2 cm and the mean tumor number was 1.6 in the CEUS group, while 3.4 cm and 1.7 in the control group, respectively (P>0.05). The clinical characteristics, recurrence results and survival outcomes were compared between two groups.

RESULTS

In the CEUS group, two isoechoic tumors were not demonstrated on unenhanced ultrasonography (US), and 63 (47%) of 134 tumors examined with CEUS were 0.3 cm larger than with unenhanced US. Furthermore, in 18.4% of 136 patients, additional 1-3 tumors were detected on CEUS. The CEUS group showed higher early tumor necrosis and lower intrahepatic recurrence than the control group. The 3-year overall survival (OS) rate and the 3-year local recurrence-free survival (LRFS) rate in the CEUS group were 50.1% and 38.3%, in contrast to 25.3% and 19.3% in the control group, respectively (P=0.002 and P<0.001).

CONCLUSIONS

CEUS provides important information for RFA treatment in patients with liver metastases and better therapeutic effect could be attained.

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.

Vascularisation pattern of chronic pancreatitis compared with pancreatic carcinoma: results from contrast-enhanced endoscopic ultrasound

Discriminating between focal chronic pancreatitis and pancreatic cancer is always a challenge in clinical medicine. Contrast-enhanced endoscopic ultrasound using Doppler techniques can uniquely reveal different vascularisation patterns in pancreatic tissue alterated by chronic inflammatory processes and even allows a discrimination from pancreatic cancer. This paper will describe the basics of contrast-enhanced high mechanical index endoscopic ultrasound (CEHMI EUS) and contrast enhanced low mechanical index endoscopic ultrasound (CELMI EUS) and explain the pathophysiological differences of the vascularisation of chronic pancreatitis and pancreatic carcinoma. Furthermore it will discuss how to use these techniques in daily clinical practice.