Contrast-enhanced ultrasound allows for interventions of hepatic lesions which are invisible on convential B-mode

Increasing utilization of contrast-enhanced ultrasound during abdominal biopsies: impact of an educational training program

RATIONAL AND OBJECTIVES

To increase utilization of contrast-enhanced ultrasound (CEUS) during ultrasound-guided targeted liver biopsies.

MATERIAL AND METHODS

Two educational training interventions performed to increase use of CEUS. First, 14 radiologists (fellowship-trained in Abdominal Imaging) given didactic teaching and case presentations on the use of CEUS. Second, hands-on teaching on how to use CEUS provided to the same group. To determine the efficacy of these two interventions, radiologists completed anonymous surveys to determine the level of understanding and acceptability of using CEUS before and 6 months after CEUS training. In addition, the percentage of CEUS assisted liver biopsies was compared for the 6 months before and 6 months after the training.

RESULTS

Pre-training survey completed by 11 radiologists and post-training survey completed by 9 radiologists. Before training, 11% survey responders use CEUS routinely, whereas 89% never or rarely used it. After training, 54% of respondents were new users and 100% reported they planned to use CEUS in the future. Unfamiliarity (71%) was the main reason for not using it. After training, 25% reported lack of comfort with using CEUS as the main reason for not using CEUS. During six months before training, CEUS was administered in 6% (10/172) of targeted liver biopsies. Six months after training, CEUS was used nearly twice as often (10%, 16/160, P = 0.09, 1-sided Boschloo test). The number of radiologists using CEUS increased to 57% (8/14) after training compared to 20% (3/14, P = 0.03, 1-sided Boschloo) before training.

CONCLUSION

Educational training intervention increases use of CEUS during ultrasound-guided targeted liver biopsies.

Contrast-Enhanced Ultrasound for Image-Guided Procedures

Contrast-enhanced ultrasound (CEUS) uses intravenously injected gas microbubbles as a pure blood pool contrast agent to demonstrate blood flow and tissue perfusion at a much higher sensitivity than color Doppler and power Doppler ultrasound. CEUS has gained traction in abdominal diagnostic imaging for improved lesion detection and characterization and a complementary problem-solving tool to CT and MRI. In addition to its diagnostic applications, CEUS has also proven useful for pre-procedure planning, procedure guidance, and post-procedure evaluation. This review provides a practical overview and guides to the application of CEUS in percutaneous, ultrasound-guided, needle-driven procedures, focusing on 2 common procedures, which illustrate the many benefits of CEUS- core needle biopsy (CNB) and percutaneous hepatic lesion ablation.

A Multicenter Randomized Controlled Study of Contrast-enhanced US versus US-guided Biopsy of Focal Liver Lesions

Background Retrospective or single-center prospective studies with relatively small samples have shown that contrast-enhanced US (CEUS) can improve the diagnostic accuracy of percutaneous biopsy, but larger prospective studies are lacking. Purpose To assess the diagnostic performance of CEUS-guided biopsy (CEUS-GB) of focal liver lesions (FLLs) compared with US-guided biopsy (US-GB) in a prospective multicenter study. Materials and Methods In this randomized controlled study conducted in nine hospitals in China between March 2016 and August 2019, adult participants with FLLs detected with US, CT, or MRI and planned for percutaneous biopsy were randomly assigned to undergo either US-GB or CEUS-GB. Lesions diagnosed as malignant at histopathologic analysis were considered true-positive findings. Benign or indeterminate lesions required further confirmation with either repeat biopsy or clinical follow-up at 6 months or later. The primary endpoint was the diagnostic accuracy rate, and comparison between groups was made using the χ² test. Results In this study, 2056 participants (1297 men, 759 women; mean age, 58 years ± 11 [SD]) were analyzed: 1030 underwent biopsy with US guidance and 1026 underwent biopsy with CEUS guidance. The overall diagnostic accuracy rate of CEUS-GB was 96% (983 of 1026) versus 93% (953 of 1030) for US-GB (P = .002), CEUS-GB enabled correct identification in 96% of participants (983 of 1026) compared with 92% (953 of 1030) with US-GB (P = .002). The negative predictive value (NPV) for both biopsy methods was moderate but significantly higher for CEUS-GB than for US-GB (74% vs 57%, P = .001). The difference was remarkable for lesions smaller than 2.0 cm, with CEUS-GB showing higher diagnostic accuracy (96% vs 88%, P = .004) and sensitivity (95% vs 87%, P = .007) than US-GB. Among lesions smaller than 2.0 cm, the accuracy of CEUS-GB and US-GB for detection of hepatocellular carcinoma was 93% and 80%, respectively (P = .008), while it was comparable for liver metastases (98% vs 95%, P = .63). Conclusion Contrast-enhanced US-guided biopsy of focal liver lesions is an effective and safe procedure with a higher diagnostic accuracy than US-guided biopsy, especially for lesions smaller than 2.0 cm and for hepatocellular carcinoma diagnosis. Clinical trial registration no. NCT02413437 © RSNA, 2022 Online supplemental material is available for this article.

The benefit of contrast-enhanced ultrasound in biopsies for focal liver lesions: a retrospective study of 820 cases

OBJECTIVE

This study compared the performance between ultrasound (US)- and contrast-enhanced US (CEUS)-guided liver biopsies and evaluated the benefit of CEUS in percutaneous biopsy for focal liver lesions (FLLs).

METHODS

We performed a retrospective study of 820 patients with FLLs, who underwent percutaneous liver biopsy in our center between 2017 and 2019. The patients were divided into two groups based on whether US (n = 362) or CEUS (n = 458) used before a biopsy. The two groups were compared based on specimen adequacy for pathological diagnosis and diagnostic accuracy of liver biopsy. Stratification analysis was performed based on lesion and protocol characteristics to provide detailed information for selecting the imaging guidance for biopsy.

RESULTS

Compared with the US group, the CEUS group yielded more acceptable samples (97.6% vs. 99.4%, p < 0.05) and improved diagnostic accuracy (92.6% vs. 96.4%, p < 0.05), and achieved better sensitivity (92.5% vs. 96.2%, p < 0.05) for liver biopsies, especially in FLLs ≥ 5 cm, heterogeneous hypoechoic FLLs, or FLLs with an obscure boundary. The CEUS group showed significantly higher accuracy compared with the US group pertaining to single-puncture biopsies (100% vs. 92.7%, p < 0.05) or biopsies with punctures ≤ 2 (97.6% vs. 94.3%, p < 0.05).

CONCLUSION

CEUS achieved an enhanced success rate for sampling and diagnostic accuracy of liver biopsies, especially in FLLs ≥ 5 cm, heterogeneous hypoechoic FLLs, or FLLs with an obscure boundary. CEUS can be used to decrease the number of punctures needed, which might increase the safety of liver biopsy.

KEY POINTS

• CEUS can help confirm an adequate biopsy site, increasing the sampling success rate and diagnostic accuracy of the liver biopsy. • CEUS can be used to decrease the number of punctures needed to improve the safety of liver biopsy. • It is recommended to use CEUS guidance for liver biopsies, especially with FLLs ≥ 5 cm, heterogeneous hypoechoic FLLs, or FLLs with an obscure boundary.

Contrast-enhanced ultrasonography to guide diagnostic and therapeutic interventional procedures

Although not necessary for the vast majority of ultrasound-guided procedures, intravenous contrast agents can be useful for procedures aimed at lesions that require contrast enhancement to be seen on ultrasonography. Using contrast-enhanced ultrasonography to guide procedures has two drawbacks: first, because enhancement from ultrasound contrast agents is short lived, it is often necessary to plan several injections; second, because the needle is poorly seen on contrast-enhanced ultrasonography, a dual image display format is necessary. Contrast-enhanced ultrasonography can be used for planning and monitoring diagnostic and therapeutic procedures, for guiding the procedures, and for follow-up. Using contrast-enhanced ultrasonography enables better results in both types of procedures; moreover, it can be used within cavities.

Contrast enhancement for ultrasound-guided interventions: when to use it and what to expect?

The use of contrast-enhanced ultrasonography (CEUS) has recently become synonymous with high-standard ultrasonography (US). From expanding the reach of US diagnostics to improving the precision of various invasive procedures, CEUS is rapidly becoming a standard in numerous niches. However, proficiency in CEUS comes with a cost, both from a learning curve and material standpoint, and as every growing field, lacks firm evidence and standardization. Therefore, in the current paper, we aim to provide an evidence-based review of available methods and to discuss the advantages and pitfalls of CEUS in interventional procedures, trying to provide strong evidence whenever available, or at least an educated expert opinion if data are lacking.

Contrast -Enhanced Ultrasound: State of the Art in North America

The Society of Radiologists in Ultrasound convened a panel of specialists in contrast-enhanced ultrasound (CEUS) to produce a white paper on noncardiac CEUS in North America. The panel met in Chicago, Illinois, on October 24 and 25, 2017. The recommendations are based on analysis of current literature and common practice strategies and are thought to represent a reasonable approach to introduce the advantages of this safe and noninvasive technique for the benefit of our patients. Characterization of liver nodules, and pediatric vascular and intravesicular applications comprise the approved indications for CEUS in the United States. They, along with the very successful off-label use of CEUS for the kidney, are included in this publication.Other off-label uses are presented with emphasis on their value and literature support in the online version.

Role of contrast-enhanced ultrasound guidance in core-needle biopsy for diagnosis of cervical tuberculous lymphadenitis

OBJECTIVE

To investigate the diagnostic value of core-needle biopsy (CNB) guided by contrast-enhanced ultrasound (CEUS) in cervical tuberculous lymphadenitis (CTL).

METHODS

178 patients with pathological confirmation of CTL were retrospectively enrolled. All of them had undergone CNB prior to the final surgery. According to the different ways of puncture guidance, they were divided into two groups: conventional ultrasound (US) group (n = 81) and CEUS group (n = 97). The comparison of diagnostic efficacy between two groups was compared and analyzed.

RESULTS

Among the 178 patients, 146 were directly diagnosed as CTL by CNB, including 59 patients in CEUS group and 87 patients in US group. The diagnostic accuracy were 89.7% (87/97) and 72.8% (59/81), respectively (P < 0.01). For subgroup analyses, differences among diagnostic efficacy ascribed to the different guiding methods were significant in medium size group (>2.0 cm and ≤3.0 cm) and large size group (>3.0 cm), 91.7% for CEUS group vs. 69.0% for US group (P < 0.05) and 84.4% for CEUS group vs. 57.7% for US group (P < 0.05), respectively.

CONCLUSIONS

In the diagnosis of CTL, compared with the US-guided CNB, CEUS-guided CNB have certain advantages, especially for larger lymph nodes.

Contrast-enhanced US for the Interventional Radiologist: Current and Emerging Applications

US is a powerful and nearly ubiquitous tool in the practice of interventional radiology. Use of contrast-enhanced US (CEUS) has gained traction in diagnostic imaging given the recent approval by the U.S. Food and Drug Administration (FDA) of microbubble contrast agents for use in the liver, such as sulfur hexafluoride lipid-type A microspheres. Adoption of CEUS by interventional radiologists can enhance not only procedure guidance but also preprocedure patient evaluation and assessment of treatment response across a wide spectrum of oncologic, vascular, and nonvascular procedures. In addition, the unique physical properties of microbubble contrast agents make them amenable as therapeutic vehicles in themselves, which can lay a foundation for future therapeutic innovations in the field in drug delivery, thrombolysis, and vascular flow augmentation. The purpose of this article is to provide an introduction to and overview of CEUS aimed at the interventional radiologist, highlighting its role before, during, and after frequently practiced oncologic and vascular interventions such as biopsy, ablation, transarterial chemoembolization, detection and control of hemorrhage, evaluation of transjugular intrahepatic portosystemic shunts (TIPS), detection of aortic endograft endoleak, thrombus detection and evaluation, evaluation of vascular malformations, lymphangiography, and percutaneous drain placement. Basic physical principles of CEUS, injection and scanning protocols, and logistics for practice implementation are also discussed. Early adoption of CEUS by the interventional radiology community will ensure rapid innovation of the field and development of future novel procedures. Online supplemental material is available for this article. ^©RSNA, 2020.

Contrast-enhanced ultrasonography to guide diagnostic and therapeutic interventional procedures

Although not necessary for the vast majority of ultrasound-guided procedures, intravenous contrast agents can be useful for procedures aimed at lesions that require contrast enhancement to be seen on ultrasonography. Using contrast-enhanced ultrasonography to guide procedures has two drawbacks: first, because enhancement from ultrasound contrast agents is short lived, it is often necessary to plan several injections; second, because the needle is poorly seen on contrast-enhanced ultrasonography, a dual image display format is necessary. Contrast-enhanced ultrasonography can be used for planning and monitoring diagnostic and therapeutic procedures, for guiding the procedures, and for follow-up. Using contrast-enhanced ultrasonography enables better results in both types of procedures; moreover, it can be used within cavities.

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.

Contrast-Enhanced Ultrasound Guidance for Interventional Procedures

Since its introduction, contrast-enhanced ultrasound (CEUS) has gained an important role in the diagnosis and management of abdominal and pelvic diseases. Contrast-enhanced ultrasound can improve lesion detection rates as well as success rates of interventional procedures when compared to conventional ultrasound alone. Additionally, CEUS enables the interventionalist to assess the dynamic enhancement of different tissues and lesions, without the adverse effects of contrast-enhanced computed tomography, such as exposure to ionizing radiation and nephrotoxicity from iodinated contrast material. This review article describes the various applications and advantages of the use of CEUS to enhance performance of ultrasound-guided interventions in the abdomen and pelvis.

The Role of US Contrast Agents in US-Guided Biopsy of Focal Liver Lesions: A Pictorial Review

US-guided percutaneous biopsy of focal liver lesions (FLL) is a classic interventional procedure performed by almost all radiology units. Typically, an incidental focal finding on US or a focal indeterminate lesion diagnosed on CT, MRI or PET/CT is referred for US-guided biopsy for final diagnosis. The introduction of microbubble US contrast agents has overcome some of the limitations of standard US in diagnosing FLLs by displaying the microvasculature together with the US morphology, which has increased both the sensitivity and the specificity. The combination of CEUS and intervention is facilitated by newer US equipment providing split-screen mode, which displays the CEUS mode alongside the standard US mode simultaneously on a single monitor. The puncture line is displayed in both modes as well as on the monitor. The interventional device (i. e., biopsy needle) is typically best visualized in the standard US mode, while the characteristic tissue pattern in an FLL is typically best visualized in CEUS mode. There are 3 main categories in which CEUS has an impact on US-guided biopsy of FLLs: • CEUS improves the visualization of FLLs • CEUS improves the quality of the biopsy specimen from an FLL • CEUS reduces the need for US-guided biopsy of an FLL In the two first categories, CEUS is utilized simultaneously with US-guided biopsy to ensure correct needle targeting. In the last category, US-guided biopsy of the FLL becomes superfluous as a result of the CEUS examination.

Additional value of contrast-enhanced ultrasonography for fusion-guided, percutaneous biopsies of focal liver lesions: prospective feasibility study

PURPOSE

To determine the value of CEUS for real-time, fusion-guided, percutaneous biopsies of focal liver lesions.

MATERIALS AND METHODS

Institutional review board approval and written informed consents were obtained for this study. Forty patients with focal liver lesions identified on CT/MRI were prospectively enrolled. For biopsy planning, real-time fusion of CT/MRI with USG (USG-Fusion) was performed, and subsequently real-time CEUS was fused with CT/MRI (CEUS-Fusion). We evaluated lesion visibility, confidence level of technical success before the procedure, and safety route accessibility on USG-Fusion and CEUS-Fusion. Occurrence of change in the biopsy target was also assessed.

RESULTS

Among 40 target lesions, nine (22.5%) lesions were invisible on USG-Fusion. After applying CEUS-Fusion, seven of nine (77.8%) lesions were visualized. Confidence level of technical success of procedure was significantly increased on CEUS-Fusion compared USG-Fusion (p = 0.02), and presumed target lesions were changed in 16 (40%) patients after CEUS-Fusion. As the lesion is necrotic, presumed target was more frequently changed after CEUS-Fusion (50.0% and 25.0%). Confirmative diagnostic results were reported in 39 (97.5%) patients. Accessibility of the safety route to target lesions did not reach statistical differences.

CONCLUSION

Applying a new, real-time CEUS-Fusion with CT/MRI improved tumor visibility and viable portion assessment, thus leading to higher operator confidence and diagnostic yield, when compared with conventional USG-Fusion.

Contemporary role of liver biopsy in hepatocellular carcinoma

A correct diagnosis of hepatocellular carcinoma (HCC) in cirrhotic patients with focal liver lesions is one of the most important issues nowadays. Probably one of the oldest debates in the hepatology community is whether to perform liver biopsy (LB) in all cirrhotic patients with focal liver lesions. We now face a time when oncology is moving towards personalized medicine. According to the current European Association for the study of Liver diseases HCC guidelines, LB has only a minor role in the management of HCC. However, the current recommendations were made more than five years ago. As time has passed, the development of high-throughput molecular technologies has helped reveal the main molecular mechanism involved in HCC development and progression. Several subtypes of HCC, with both molecular and histological characterization, have been described. Importantly, some of these subtypes have prognostic impact. In the context of personalized treatment, the role of LB will be carefully reconsidered. Until then, it is mandatory to know the various techniques of LB, their performances, complications and limitations. The balance of risk and benefit defines many of the decisions that we make as providers of medical care. In this review, we discuss not only the risks associated with LB, but also the benefits of biopsy in various clinical scenarios. Not long from now, the role of LB will be reconsidered. It is possible that we will go back in time and once again use biopsy for HCC diagnosis. Then again, we may move back to the future to try to improve the use of liquid biopsy in the follow-up of HCC patients after various treatment modalities.

Use of Ultrasound Contrast Agents in Relation to Percutaneous Interventional Procedures: A Systematic Review and Pictorial Essay

The aim of this article is to provide an inventory of the use of contrast-enhanced ultrasound (CEUS) in relation to percutaneous interventional procedures. The article is structured into a systematic literature review followed by a clinical part relating to percutaneous CEUS-guided procedures. A literature search identified 3109 records. After abstract screening, 55 articles were analyzed and supplemented with pictorial material to explain the techniques. In conclusion, the best-evidenced indications for CEUS-guided interventions are biopsy and ablation of inconspicuous or B-mode-invisible tumors, intraprocedural ablation control and follow-up, as well as percutaneous transhepatic cholangiography and drainage procedures.

Contrast-Enhanced Ultrasound of the Liver: Optimizing Technique and Clinical Applications

OBJECTIVE

The purpose of this article is to review the general principles, technique, and clinical applications of contrast-enhanced ultrasound of the liver.

CONCLUSION

Proper technique and optimization of contrast-enhanced ultrasound require a balance between maintaining the integrity of the microbubble contrast agent and preserving the ultrasound signal. Established and emerging applications in the liver include diagnosis of focal lesions, aiding ultrasound-guided intervention, monitoring of therapy, and aiding surgical management.

Contrast enhanced ultrasound guided biopsies of liver lesions not visualized on standard B-mode ultrasound-preliminary experience

Background

To assess the technical success of contrast enhanced ultrasound (CEUS) guided biopsies of liver lesions poorly visualized on B-mode ultrasound.

Methods

Patients were selected during the procedure based on the real-time clinical scenario of unsatisfactory B-mode ultrasound lesion visualization and all patients would have otherwise undergone CT guided liver lesion biopsy. A total of 26 patients underwent CEUS guided biopsy and were included in this retrospective analysis. The review of the patients' files included demographic information, lesion characteristics on imaging, procedural details and pathology outcome. Technical success was defined as concordance between the radiological findings, pathology report and clinical follow-up-demonstrating lack of need for re-biopsy or re-biopsy with identical pathological results. Patients with less than 2 months follow-up were excluded from the study.

Results

CEUS guided liver biopsy was successful in 23 out of 26 patients (88.5%). The average procedure time was 30.7±12.3 minutes and the average lesion size was 2.2±1.7 cm. The majority of lesions (80.8%) were hypoenhancing on the delayed phase of CEUS. The mean number of samples taken from each lesion per procedure was 3.2 (±1.7).

Conclusions

CEUS guidance biopsies of focal liver lesions (FLL) that were difficult to visualize on B-mode ultrasound demonstrated high success rate and may be an evolving image guidance modality in selected patients to avoid CT guided procedures.

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.

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.

Real-time contrast-enhanced ultrasound-guided biopsy of focal hepatic lesions not localised on B-mode ultrasound

OBJECTIVE

To prospectively evaluate the technical feasibility of percutaneous real-time contrast-enhanced ultrasound (CEUS) guided biopsy of focal hepatic lesions that are not confidently localised on B-mode US.

METHODS

The study included 44 patients (mean age, 61.3 years) whose biopsy target could not be confidently localised on B-mode US performed by two independent radiologists. Biopsy was attempted under the guidance of both CEUS and B-mode US simultaneously displayed on a single monitor. Final diagnosis was established based on the pathological examination of the biopsy specimen as well as on clinical and radiological follow-up.

RESULTS

The size and depth of the target lesions were 18.0 +/- 9.0 mm (mean +/- SD) and 41.8 +/- 17.2 mm respectively. Five patients with negative or indistinct CEUS findings did not undergo biopsy, while 39 patients completed the biopsy. In 38 of the 39 patients, the biopsy result was concordant with the final diagnosis. In the remaining one patient, the biopsy failed to prove metastasis. As there were six cases of technical failure, the technical success rate was 86% (38/44). The sensitivity in diagnosing malignancy was 88% (30/34).

CONCLUSION

Real-time CEUS-guided biopsy is technically feasible for hepatic focal lesions that are not confidently localised on B-mode US.

Technology Insight: advances in liver imaging

The role of diagnostic imaging in the assessment of liver disease continues to gain in importance. The classic techniques used for liver imaging are ultrasonography, CT and MRI. In the past decade, there have been significant advances in all three techniques. In this article, we discuss the advances in ultrasonography, CT and MRI that have improved assessment of focal and diffuse liver disease, including the development of hardware, software, processing algorithms and procedural innovations.

CO2-enhanced sonographically guided radiofrequency ablation and transcatheter arterial chemoembolization for small hepatocellular carcinoma poorly defined on conventional sonography

We report a case of hepatocellular carcinoma located just below the right hemidiaphragm that was diagnosed as having hepatitis C virus-related cirrhosis 12 years ago. Although the lesion was not clear on conventional sonography, it was clearly defined on CO(2)-enhanced sonography, allowing safe and accurate radiofrequency ablation. By combining radiofrequency ablation with transcatheter arterial chemoembolization, extensive cauterization and complete tumor necrosis were obtained with only 1 session of treatment. The patient had no serious adverse effects and has shown no recurrence during 35 months of follow-up.

The role of contrast-enhanced sonography of focal liver lesions before percutaneous biopsy

OBJECTIVE

The objective of our study was to evaluate the clinical utility of performing contrast-enhanced sonography before percutaneous biopsy of focal liver lesions.

SUBJECTS AND METHODS

One hundred eighty-six patients with focal liver lesions detected on either sonography or contrast-enhanced CT were randomly divided into two groups: a group who underwent contrast-enhanced sonography and another who underwent unenhanced sonography. The contrast-enhanced sonography group (79 patients, 129 lesions) underwent SonoVue-enhanced sonography before biopsy, and the unenhanced sonography group (107 patients, 143 lesions) did not undergo contrast-enhanced sonography before biopsy. Conventional sonography was used in all patients to guide the biopsy procedures. The pathologic diagnosis was considered definitive and final if the biopsy result was malignant. If the initial biopsy result was benign or negative for malignancy, then the result was either confirmed or denied on the basis of contrast-enhanced CT, MRI, angiography, serum alpha-fetoprotein level, or clinical follow-up over a period of 6 months. In some patients with suspected malignancy, biopsy was repeated when considered necessary during the follow-up. The diagnostic accuracy of the initial biopsy was defined as the percentage of the total number of lesions that were correctly diagnosed at the initial biopsy. The difference in diagnostic accuracy between the two groups was analyzed to evaluate the value of performing contrast-enhanced sonography before biopsy.

RESULTS

Of the 129 lesions in the contrast-enhanced sonography group, 28 (21.7%) were benign and 101 (78.3%) were malignant. Of the 143 lesions in the unenhanced sonography group, 36 (25.2%) were benign and 107 (74.8%) were malignant. There was no significant difference in the distribution of malignant and benign lesions in these two groups (p > 0.05). There was no statistically significant difference in the distribution of lesions by size between the contrast-enhanced and unenhanced sonography groups (chi(2) = 0.619, p > 0.05). The diagnostic accuracy of the initial biopsy was significantly higher in the contrast-enhanced sonography group than in the unenhanced sonography group (95.3% vs 87.4%, respectively; p < 0.05). The diagnostic accuracy of the initial biopsy for malignant lesions < or = 2.0 cm was also significantly higher in the contrast-enhanced sonography group than in the unenhanced sonography group (97.1% vs 78.8%, respectively; p < 0.05). No major complications occurred in our study except one case of pneumothorax in the unenhanced sonography group.

CONCLUSION

Contrast-enhanced sonography before percutaneous focal liver lesion biopsy improved the diagnostic accuracy of the procedure by providing important intralesional information for differentiating viable, denaturalized, or necrotic tissue; consequently, by providing more accurate information about the site of biopsy even in lesions < or = 2.0 cm, contrast-enhanced sonography before biopsy reduced the number of puncture attempts.