Contrast-enhanced ultrasound for the characterization of focal liver lesions--diagnostic accuracy in clinical practice (DEGUM multicenter trial)

On-Site Diagnostic Ability of CEUS/CT/MRI for Hepatocellular Carcinoma (2019-2022): A Multicenter Study

OBJECTIVES

To compare the on-site diagnostic performance of contrast-enhanced ultrasound (CEUS), computed tomography (CECT), and magnetic resonance imaging (CEMRI) for hepatocellular carcinoma (HCC) across diverse practice settings.

METHODS

Between May 2019 and April 2022, a total of 2085 patients with 2320 pathologically confirmed focal liver lesions (FLLs) were enrolled. Imaging reports were compared with results from pathology analysis. Diagnostic performance was analyzed in defined size, high-risk factors for HCC, and hospital volume categories.

RESULTS

Three images achieved similar diagnostic performance in classifying HCC from 16 types of FLLs, including HCC ≤2.0 cm. For HCC diagnosis at low-volume hospitals and HCC with high-risk factors, the accuracy and specificity of CEUS were comparable to CECT and CEMRI, while the sensitivity of CEUS (77.4 and 89.5%, respectively) was inferior to CEMRI (87.0 and 92.8%, respectively). The diagnostic accuracy of CEUS + CEMRI and CEUS + CECT increased by 7.8 and 6.2% for HCC ≤2.0 cm, 8.0 and 5.0% for HCC with high-risk factors, and 7.4 and 5.5% for HCC at low-volume hospitals, respectively, compared with CEMRI/CECT alone.

CONCLUSIONS

Compared with CECT and CEMRI, CEUS provides adequate diagnostic performance in clinical first-line applications at high-volume hospitals. Moreover, a higher diagnostic performance for HCC is achieved by combining CEUS with CECT/CEMRI compared with any single imaging technique.

[Contrast-Enhanced Ultrasound of Fibrolamellar Hepatocellular Carcinoma]

We present the case of a 24-year-old male patient, who was admitted for endoscopy due to sustained pain in the upper abdomen with nausea and postprandial fullness without vomiting for more than 5 months. In the physical examination, an epigastric induration was found. Endoscopy revealed an external impression of the proximal duodenum. Beyond that, normal findings could be ascertained in gastroscopy and ileo-colonoscopy. Abdominal ultrasound identified a large hypoechoic lesion in the left liver lobe with a sharp delineation. Along the upper mesenteric vessels, enlarged lymphnodes were visible with contact to the proximal duodenum. Contrast-enhanced ultrasound (CE-US) was conducted and revealed the typical perfusion pattern of hepatocellular carcinoma. For further assessment, an ultrasound-guided core-biopsy of the lesion was performed. The histopathological evaluations resulted in the diagnosis of a hepatocellular carcinoma of fibrolamellar subtype.With the present case, we want to illustrate the perfusion pattern of a fibrolamellar hepatocellular carcinoma in contrast-enhanced ultrasound. Even though the tumor tissue is surrounded by lamellar bands of fibrosis with collagen-rich fibers, the perfusion pattern is consistent with the previously known appearance of HCC in CE-US.

Quantitative evaluation of colorectal tumour vasculature using contrast-enhanced ultrasound: Correlation with angiogenesis and prognostic significance

BACKGROUND

Ultrasound is a vital tool for the diagnosis and management of colorectal cancer (CRC). Contrast-enhanced ultrasound (CEUS) is a non-invasive, safe, and cost-effective method for evaluating tumour blood vessels, that play a crucial role in tumour growth and progression.

AIM

To explore CEUS's role in the quantitative evaluation of CRC blood vessels and their correlation with angiogenesis markers and prognosis.

METHODS

This study prospectively enrolled 100 patients with CRC confirmed by histopathology. All patients received preoperative CEUS examinations. Quantitative parameters, such as peak intensity (PI), time to peak (TTP), and area under the curve (AUC), were derived from time-intensity curve (TIC) analysis. Tumour tissue samples were obtained during surgery and examined immunohistochemically to assess the expression of angiogenesis markers, including vascular endothelial growth factor (VEGF) and microvessel density (MVD). The correlation between CEUS parameters, angiogenesis markers, and clinicopathological features was evaluated using appropriate statistical tests.

RESULTS

Quantitative CEUS parameters (PI, TTP, and AUC) showed significant correlations with VEGF expression (P < 0.001) and MVD (P < 0.001), indicating a strong link between tumour blood vessels and angiogenesis. Increased PI, reduced TTP, and expanded AUC values were significantly related to higher tumour stage (P < 0.001), lymph node metastasis (P < 0.001), and distant metastasis (P < 0.001). Furthermore, these parameters were recognized as independent predictors of overall survival and disease-free survival in multivariate analysis (P < 0.001).

CONCLUSION

CEUS has a high potential in guiding treatment planning and predicting patient outcomes. However, more comprehensive, multicentre studies are required to validate the clinical utility of CEUS in CRC management.

Ceusia-Breast: computer-aided diagnosis with contrast enhanced ultrasound image analysis for breast lesions

BACKGROUND

In recent years, contrast-enhanced ultrasonography (CEUS) has been used for various applications in breast diagnosis. The superiority of CEUS over conventional B-mode imaging in the ultrasound diagnosis of the breast lesions in clinical practice has been widely confirmed. On the other hand, there have been many proposals for computer-aided diagnosis of breast lesions on B-mode ultrasound images, but few for CEUS. We propose a semi-automatic classification method based on machine learning in CEUS of breast lesions.

METHODS

The proposed method extracts spatial and temporal features from CEUS videos and breast tumors are classified as benign or malignant using linear support vector machines (SVM) with combination of selected optimal features. In the proposed method, tumor regions are extracted using the guidance information specified by the examiners, then morphological and texture features of tumor regions obtained from B-mode and CEUS images and TIC features obtained from CEUS video are extracted. Then, our method uses SVM classifiers to classify breast tumors as benign or malignant. During SVM training, many features are prepared, and useful features are selected. We name our proposed method "Ceucia-Breast" (Contrast Enhanced UltraSound Image Analysis for BREAST lesions).

RESULTS

The experimental results on 119 subjects show that the area under the receiver operating curve, accuracy, precision, and recall are 0.893, 0.816, 0.841 and 0.920, respectively. The classification performance is improved by our method over conventional methods using only B-mode images. In addition, we confirm that the selected features are consistent with the CEUS guidelines for breast tumor diagnosis. Furthermore, we conduct an experiment on the operator dependency of specifying guidance information and find that the intra-operator and inter-operator kappa coefficients are 1.0 and 0.798, respectively.

CONCLUSION

The experimental results show a significant improvement in classification performance compared to conventional classification methods using only B-mode images. We also confirm that the selected features are related to the findings that are considered important in clinical practice. Furthermore, we verify the intra- and inter-examiner correlation in the guidance input for region extraction and confirm that both correlations are in strong agreement.

Artificial intelligence for the classification of focal liver lesions in ultrasound - a systematic review

Focal liver lesions are detected in about 15% of abdominal ultrasound examinations. The diagnosis of frequent benign lesions can be determined reliably based on the characteristic B-mode appearance of cysts, hemangiomas, or typical focal fatty changes. In the case of focal liver lesions which remain unclear on B-mode ultrasound, contrast-enhanced ultrasound (CEUS) increases diagnostic accuracy for the distinction between benign and malignant liver lesions. Artificial intelligence describes applications that try to emulate human intelligence, at least in subfields such as the classification of images. Since ultrasound is considered to be a particularly examiner-dependent technique, the application of artificial intelligence could be an interesting approach for an objective and accurate diagnosis. In this systematic review we analyzed how artificial intelligence can be used to classify the benign or malignant nature and entity of focal liver lesions on the basis of B-mode or CEUS data. In a structured search on Scopus, Web of Science, PubMed, and IEEE, we found 52 studies that met the inclusion criteria. Studies showed good diagnostic performance for both the classification as benign or malignant and the differentiation of individual tumor entities. The results could be improved by inclusion of clinical parameters and were comparable to those of experienced investigators in terms of diagnostic accuracy. However, due to the limited spectrum of lesions included in the studies and a lack of independent validation cohorts, the transfer of the results into clinical practice is limited.

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.

Hydralazine-augmented contrast ultrasound imaging improves the detection of hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) detection with B-mode and contrast-enhanced ultrasound (CUS) imaging often varies between subjects, especially in patients with background cirrhosis. Various factors contribute to this variability, including the tumor blood flow, tumor size, internal echoes, and its location in livers with diffuse fibro-cirrhotic changes.

OBJECTIVE

Towards improving lesion detection, this study evaluates a vasodilator, hydralazine, to enhance the visibility of HCC by reducing its blood flow relative to the surrounding liver tissue.

METHODS

HCC were analyzed for tumor visibility measured for B-mode, CUS, and hydralazine-augmented-contrast ultrasound (HyCUS) in an autochthonous HCC rat model. 21 tumors from 12 rats were studied. B-mode and CUS images were acquired before hydralazine injection. Rats received an intravenous hydralazine injection of 5 mg/kg, then images were acquired 20 min later. Four rats were used as controls. The difference in echo intensity of the lesion and the surrounding tissue was used to determine the visibility index (VI).

RESULTS

The visibility index for HCC was found to be significantly improved with the use of HyCUS imaging compared to traditional B-mode and CUS imaging. The visibility index for HCC was 16.5 ± 2.8 for HyCUS, compared to 5.3 ± 4.8 for B-mode and 4.1 ± 3.8 for CUS. The differences between HyCUS and the other imaging modalities were statistically significant, with p-values of 0.001 and 0.02, respectively. Additionally, when compared to control cases, HyCUS showed higher discrimination of HCC (VI = 6.4 ± 1.2) with a p-value of 0.003, while B-mode (VI = 6.7 ± 1.4, p = 0.5) and CUS (VI = 6.4 ± 1.2, p = 0.3) showed lower discrimination.

CONCLUSION

Vascular blood flow modulation by hydralazine enhances the visibility of HCC. HyCUS offers a potential problem-solving method for detecting HCC when B-mode and CUS are unsuccessful, especially with background fibro-cirrhotic liver disease. Future evaluation of the approach in humans will determine its translatability for clinical applications.

Contrast-Enhanced Ultrasound Findings in Patients with Rare Solitary Necrotic Nodule of the Liver - a Multicenter Report

PURPOSE

 This multicenter retrospective study highlights the contrast-enhanced ultrasound (CEUS) findings in a series of histologically proven solitary necrotic nodules (SNN) of the liver, a poorly understood pathologic entity of uncertain origin that mimics malignancy.

MATERIALS AND METHODS

 22 patients (M/F 13/9; mean age 59.4 years, SD ± 10.7, range 35-81) with histological diagnosis of SNN and CEUS were selected from clinical, imaging, and pathological archives of 7 US interventional centers, each of which provided 1 to 6 cases (mean 2.8). Pathological diagnosis was made on 20 US-guided biopsies and 2 surgical specimens. 2 patients had 2 SNNs with identical CEUS findings so that imaging analysis was carried out on 24 nodules.

RESULTS

 SNN was an incidental finding in healthy people in 10 cases (45.5 %), and it was discovered during follow-up for either known extrahepatic malignancies (9 cases = 41 %) or chronic liver disease (3 cases = 13.5 %). SNNs had a mean size of 19.3 mm (SD ± 6.5, range 9-40). On B-mode US, SNNs appeared hypoechoic in 14 cases (66.7 %), "target-like" in 7 cases (29.2 %), and homogeneously hyperechoic in 1 case (4.1 %). On CEUS, all lesions appeared devoid of contrast enhancement ("punched out" aspect) in the arterial, portal venous, and late phases after US contrast agent injection. A uniformly thin, hyperenhancing ring in the early arterial phase and isoenhanced with the surrounding parenchyma in the portal venous and late phases was found in 10 nodules (41.6 %). Clinical and imaging follow-up (mean duration 42.2 months, SD ± 34.9, range 2-108) was available in 15 patients with 16 SNNs: no changes in size and echostructure were seen.

CONCLUSION

 CEUS can contribute to the diagnosis of SNN when a "punched out" appearance in all vascular phases with or without thin rim enhancement in the very early arterial phase is present in healthy subjects in whom a focal liver lesion is incidentally found. In patients with a history of chronic liver disease or malignancy, US-guided biopsy represents the unavoidable first-line diagnostic modality.

Ultrasound-New Techniques Are Extending the Applications

BACKGROUND

Sonography is often the first imaging procedure to be used in diagnostic investigation of the abdomen. The aim of this article is to provide a new interdisciplinary overview of recent groundbreaking advances in this modality.

METHODS

A selective survey of the literature in PubMed was conducted. The literature search was carried out in 2021-2022 and included publications over the period 2004-2022.

RESULTS

The novel sonographic software techniques can be divided into algorithms that deal with conventional B-scan optimization and new programs that extend the scope of sonographic examination. The latter include elastography, contrast-enhanced sonography, and image fusion in combination with other cross-sectional imaging modalities. Elastography can be used to assess the presence of steatosis, fibrosis, or cirrhosis in patients with liver disease. One study reported diagnostic accuracy of 84-87% for the diagnosis of significant fibrosis (F2), 89-91% for the diagnosis of severe fibrosis (F3), and 92-93% for the diagnosis of liver cirrhosis (F4). Contrast-enhanced sonography is used for evaluation of tumors and trauma. A prospective multicenter study found sensitivity of 95.8% for the characterization of malignant lesions and specificity of 83.1% for benign lesions. Image fusion has the potential to improve the diagnostic assessment of parenchymatous organs, vascular conditions, and the prostate.

CONCLUSION

With continuous improvement of the B-scan and the development of high-frequency probes and novel investigation techniques, sonography has become established as an increasingly autonomous examination procedure.

Imaging strategy for focal nodular hyperplasia in children: long-term experience from two specialist European centres

BACKGROUND

Focal nodular hyperplasia (FNH) in children is a rare but benign tumour, which must be differentiated from malignant entities to avoid unnecessary treatment, leading to potential morbidity.

OBJECTIVES

To provide data on imaging findings of these lesions with a suggested algorithm for diagnosis, sampling and follow-up.

MATERIALS AND METHODS

This retrospective review evaluated imaging of all patients diagnosed with FNH in two tertiary referral centres in Europe between 1975 and 2018.

RESULTS

One hundred and four patients with 137 tumours were reviewed. The mean age at presentation was 8.2 years. The median tumour size was 5 cm (range: 0.3-29 cm). Multiple lesions were seen in 16.3% of patients. The male-to-female ratio was 1:2.

CONCLUSION

FNH with typical features on imaging can be safely followed up once the diagnosis has been established. The use of contrast-enhanced ultrasound and magnetic resonance imaging allows accurate characterisation in most cases. Histological sampling is only advised when there is diagnostic doubt. Atypical arterial enhancement of FNH should prompt the search for a congenital portosystemic shunt.

Shear Wave Dispersion Imaging for the Characterization of Focal Liver Lesions - A Pilot study

PURPOSE

Shear wave dispersion imaging is a novel ultrasound-based technique, which analyzes the speed of different shear wave components depending on their frequency. The dispersion of shear wave speed correlates with the viscosity of the liver parenchyma. The aim of this prospective study was to evaluate the use of shear wave dispersion imaging in focal liver lesions in the non-cirrhotic liver.

METHODS

Patients with unclear focal liver lesions in B-mode ultrasound were prospectively assigned to shear wave dispersion imaging (m/s/kHz). Measurements were conducted within the lesion and in the liver parenchyma of the right liver lobe using an intercostal window. Histology and contrast-enhanced ultrasound served as the reference for the characterization of the lesions.

RESULTS

Out of 46 patients included in this study, 24 had liver metastases and 22 had benign liver lesions. Benign lesions consisted mostly of hemangiomas (n=12) and focal nodular hyperplasia (n=8). Malignant lesions showed significantly lower shear wave dispersion (13.0±2.45 m/s/kHz) compared to benign tumors (15.2±2.74 m/s/kHz, p<0.01). In further subgroup analysis, the difference was significant for hemangiomas (15.32±2.42 m/s/kHz, p=0.04) but not for FNHs (14.98±3.36 m/s/kHz, p=0.38). The dispersion of reference liver parenchyma did not differ significantly between the groups (p=0.54).

CONCLUSION

The quantification of viscosity by shear wave dispersion is a new parameter for the characterization of focal liver lesions with higher dispersion values in hemangiomas and lower dispersion values in metastases. However, it cannot differentiate reliably between benign and malignant lesions.

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.

Effects of Organizational Atmosphere and Organizational Practice on Knowledge, Attitude, and Practice Toward Diffusion and Utilization of Hepatic Contrast-Enhanced Ultrasound Among Physicians

Background

Promoting technology diffusion and utilization is a key measure to address the great disparity in technical capacity within integrated health systems. However, even the effectiveness and appropriateness regarding technology has been widely recognized, its diffusion and utilization are still stagnant. The mechanisms that influence the technology from being recognized to being widely applied in practice remain largely unknown.

Purpose

Taking hepatic contrast-enhanced ultrasound (CEUS) as an example, this study aimed to investigate the comprehensive influencing mechanism of organizational atmosphere and organizational practice on the knowledge, attitude, and practice toward diffusion and utilization of hepatic CEUS in the medical alliance.

Methods

Based on the integration of organizational ready for change (ORC) and knowledge-attitude-practice (KAP), a structured questionnaire was developed. A multistage random sampling method was applied to investigate physicians who directly use CEUS working at the liver disease-related departments of sampled health institutions. Structural equation modeling (SEM) was used to verify the proposed hypotheses, and determine the relationship between the factors.

Results

In total, 292 physicians were included. SEM results demonstrated that knowledge influenced both attitude and practice, while attitude positively predicted practice. Organizational practice and organizational atmosphere associated positively with each other. Organizational atmosphere positively affected the physicians' attitude toward CEUS diffusion and utilization (β = 0.425, p < 0.001), while organizational practice positively affected corresponding knowledge (β = 0.423, p < 0.001) and practice (β = 0.275, p < 0.001). Additionally, there was a partial mediating effect between organizational practice and physicians' CEUS diffusion and utilization behavior.

Conclusion

By verifying the influencing mechanism of organizational atmosphere and organizational practice on the physicians' KAP of hepatic CEUS diffusion and utilization, this study benefit tailoring strategies for promoting technology diffusion and utilization within medical alliance. It is recommended to develop an organizational atmosphere of advocating technology innovation, establish organizational support mechanism (SM) with multiple concrete supporting countermeasures, and so on.

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.

Very Low Frequency Radial Modulation for Deep Penetration Contrast-Enhanced Ultrasound Imaging

Contrast-enhanced ultrasound imaging allows vascular imaging in a variety of diseases. Radial modulation imaging is a contrast agent-specific imaging approach for improving microbubble detection at high imaging frequencies (≥7.5 MHz), with imaging depth limited to a few centimeters. To provide high-sensitivity contrast-enhanced ultrasound imaging at high penetration depths, a new radial modulation imaging strategy using a very low frequency (100 kHz) ultrasound modulation wave in combination with imaging pulses ≤5 MHz is proposed. Microbubbles driven at 100 kHz were imaged in 10 successive oscillation states by manipulating the pulse repetition frequency to unlock the frame rate from the number of oscillation states. Tissue background was suppressed using frequency domain radial modulation imaging (F-RMI) and singular value decomposition-based radial modulation imaging (S-RMI). One hundred-kilohertz modulation resulted in significantly higher microbubble signal magnitude (63-88 dB) at the modulation frequency relative to that without 100-kHz modulation (51-59 dB). F-RMI produced images with high contrast-to-tissue ratios (CTRs) of 15 to 22 dB in a stationary tissue phantom, while S-RMI further improved the CTR (19-26 dB). These CTR values were significantly higher than that of amplitude modulation pulse inversion images (11.9 dB). In the presence of tissue motion (1 and 10 mm/s), S-RMI produced high-contrast images with CTR up to 18 dB; however, F-RMI resulted in minimal contrast enhancement in the presence of tissue motion. Finally, in transcranial ultrasound imaging studies through a highly attenuating ex vivo cranial bone, CTR values with S-RMI were as high as 23 dB. The proposed technique demonstrates successful modulation of microbubble response at 100 kHz for the first time. The presented S-RMI low-frequency radial modulation imaging strategy represents the first demonstration of real-time (20 frames/s), high-penetration-depth radial modulation imaging for contrast-enhanced ultrasound imaging.

The diagnostic value of contrast-enhanced ultrasound LI-RADS for hepatocellular carcinoma in patients with cirrhosis and chronic hepatitis B

PURPOSE

To explore the diagnostic value of American College of Radiology Contrast-Enhanced Ultrasound-Liver Imaging Reporting and Data System (ACR-CEUS-LI-RADS) for hepatocellular carcinoma (HCC) in patients with cirrhosis and chronic hepatitis B.

METHODS

A total of 205 patients at high risk of HCC with solitary hepatic nodule were enrolled and retrospectively analyzed. All patients were over 18 years old and had a single lesion with a diameter < 50 mm. Lesions were categorized according to size and contrast enhancement patterns in the arterial, portal venous and late phases. Diagnostic efficacy of CEUS LI-RADS for HCC, and the rate of non-HCC malignancies in the LR-M class were compared between patients with cirrhosis and chronic hepatitis B.

RESULTS

Of all 205 nodules (median nodule size was 34 mm), 142 (69.3%) were HCC. Of the 127 (61.9%) LR-5 category nodules, 95.8% (92/96) nodules were corresponded to HCC in cirrhosis, while 61.3% (19/31) nodules were corresponded to HCC in chronic hepatitis B (P = 0.000). Positive predictive value (PPV) of LR-5 category for HCC was 95.8% in cirrhosis and 61.3% in chronic hepatitis B (P = 0.000). More category of LR-4 nodules were proved to be HCC in patients with cirrhosis than chronic hepatitis B (80.0% vs 8.3%, P = 0.000). Of 41 LR-M category nodules, more non-HCC malignancies were found in chronic hepatitis B (76.0%) than that in cirrhosis (25.0%, P = 0.001).

CONCLUSIONS

The LR-5 category is highly specific for the diagnosis of HCC in patients with cirrhosis. However, LR-5 category nodules require further CT or MRI examination or histological confirmation in patients with chronic hepatitis B for its unsatisfactory PPV for HCC.

One stop shop approach for the diagnosis of liver hemangioma

Hepatic hemangioma is usually detected on a routine ultrasound examination because of silent clinical behaviour. The typical ultrasound appearance of hemangioma is easily recognizable and quickly guides the diagnosis without the need for further investigation. But there is also an entire spectrum of atypical and uncommon ultrasound features and our review comes to detail these particular aspects. An atypical aspect in standard ultrasound leads to the continuation of explorations with an imaging investigation with contrast substance [ultrasound/ computed tomography/or magnetic resonance imaging (MRI)]. For a clinician who practices ultrasound and has an ultrasound system in the room, the easiest, fastest, non-invasive and cost-effective method is contrast enhanced ultrasound (CEUS). Approximately 85% of patients are correctly diagnosed with this method and the patient has the correct diagnosis in about 30 min without fear of malignancy and without waiting for a computer tomography (CT)/MRI appointment. In less than 15% of patients CEUS does not provide a conclusive appearance; thus, CT scan or MRI becomes mandatory and liver biopsy is rarely required. The aim of this updated review is to synthesize the typical and atypical ultrasound aspects of hepatic hemangioma in the adult patient and to propose a fast, non-invasive and cost-effective clinical-ultrasound algorithm for the diagnosis of hepatic hemangioma.

Comparative the clinical value of contrast-enhanced ultrasonography, enhancement CT and MRI for diagnosing of liver lesions

BACKGROUND

To investigate the accuracy of contrast-enhanced ultrasonography, CT-enhancement and MRI in the diagnosis of liver-occupying lesions.

METHODS

176 patients with suspected liver lesions in our hospital were retrospectively studied from July 2014 to July 2016. All of the 176 patients were diagnosed by contrast-enhanced ultrasonography, enhanced CT and MRI, and the pathological examination was performed. The results of pathological examination were regarded as the results of the diagnosis. The diagnostic accuracywas then compared among contrast-enhanced ultrasound, enhanced CT and MRI of these patients.

RESULTS

The results of contrast-enhanced ultrasonography showed that 164 of the 176 patients had liver-occupying lesions, and the accuracy of the diagnosis was 95.35%, which was significantly higher than that of CT enhancement and MRI (80.23% 84.30%). The accuracy of contrast-enhanced ultrasonography, in the diagnosis of primary liver cancer was significantly higher than that of CT enhancement and MRI (P <  0.05), and the difference was significant difference (P <  0.05).

CONCLUSIONS

The examination of contrast-enhanced ultrasonography is relatively simple, and the patients can get duplicateexamination, so we should choose the contrast-enhanced ultrasonography as the preferred method of diagnosis in liver mass, especially primary liver cancer.

Characterization of Focal Liver Masses: A Multicenter Comparison of Contrast-Enhanced Ultrasound, Computed Tomography, and Magnetic Resonance Imaging

OBJECTIVES

To demonstrate the usefulness of contrast-enhanced ultrasound (CEUS) for the evaluation of focal liver masses via a direct comparison to standard ultrasound and computed tomography/magnetic resonance imaging (CT/MRI).

METHODS

A cohort of 214 patients with previously undiagnosed focal liver masses were included from 5 different centers. Each patient was imaged using CEUS and CT and/or MRI. Anonymized and randomized images were interpreted by 4 separate blind readers from 3 of the participating centers (2 readers for CEUS and 2 readers for CT/MRI). Readers were blinded to patient demographics and past medical history. Readers were asked to decide if the lesion was benign or malignant, provide a final diagnosis for the lesion, and provide a confidence interval. Results were compared to truth standard from pathology or expert consensus.

RESULTS

In determination of malignancy, CEUS had a sensitivity of 95%, specificity of 82%, PPV of 82%, NPV of 95%, statistically better than standard ultrasound (sensitivity 82%, specificity 56%, PPV 60%, NPV 78%) with P < .01 and not statistically different from CT (sensitivity 90%, specificity 73% PPV 81%, NPV 86%) or MRI (sensitivity 85%, specificity 79%, PPV 68%, NPV 91%) with P ≥ .01. In assigning a final diagnosis, CEUS had an accuracy of 78% statistically better than standard ultrasound (46%) with P < .01 and not statistically different from CT (68%) or MRI (71%) with P > .01.

CONCLUSIONS

In the evaluation of focal liver lesions, both for determination of malignancy and in accuracy of final diagnosis, CEUS performs better than standard ultrasound and at least equivalent to both CT and MRI.

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

Background

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

Results

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

Conclusion

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

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.

Contrast enhanced ultrasound in diagnosing liver lesion that spontaneously disappeared: A case report

BACKGROUND

Focal liver lesions (FLLs) are abnormal masses that are distinguishable from the surrounding liver parenchyma, solid or cystic and may be benign or malignant. They are usually detected incidentally on abdominal examinations. The classification of FLLs is very important as it directly determines the diagnosis and treatment of patients.

CASE SUMMARY

A 46-year-old male patient was admitted into the hospital with tarry stool, during the investigation of this issue an incidental FLL was detected. Upon further investigation of this “incidentaloma” computerized tomography and magnetic resonance imaging reached contradictory conclusions. The lesion was then further investigated using contrast-enhanced ultrasound (CEUS) with an initial diagnosis of idiopathic FLL was acquired and observation of the FLL over time need for final diagnosis, however in the follow up the FLL disappeared spontaneously.

CONCLUSION

CEUSs value for characterization of FLLs is undeniable, especially when other methods produce inconsistent results, is undeniable but with its limitations. Why and how the FLL disappeared is not known, and can be only hypothesized it was a pseudolesion.

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.

Intraoperative contrast-enhanced ultrasound can have a crucial role in surgical decision-making during hepato-pancreatico-biliary surgery - Analysis of impact and input

OBJECTIVE

To assess the impact and procedural input of intraoperative ultrasound (IOUS) with contrast-enhanced ultrasound (CEUS) and ultrasound elastography on surgical decision making during the procedure and consequently the outcome after hepato-pancreatico-biliary (HPB) surgery.

MATERIALS AND METHODS

Data of 50 consecutive patients, who underwent HPB surgery from 04/2018 to 07/2018 were prospectively collected for this study. During surgery, IOUS with a high-resolution ultrasound device using CEUS after bolus injection of 2.4-5 ml dulphur hexafluoride microbubbles using a 6-9 MHz probe and a share wave and strain elastography was performed by an experienced examiner. Process and time analysis were carried out using mobile phone timer.

RESULTS

The IOUS with CEUS and elastography correctly identified 42 malignant tumors and 4 benign lesions. In 3 cases, the examination provided false positive result (identifying 3 benign lesions as malignant) and in 1 case a malignant lesion was incorrectly assessed as benign (sensitivity 97,7%, specificity 57,1%, PPV 93,3% and NPV 80%).The specific question by the surgeon could be answered successfully in 98% of the cases. In 76% of the cases, there was a modification (42%) or a fundamental change (34%) of the planned surgical approach due to the information provided by the IOUS. Within the last group, the IOUS had a major impact on therapy outcome. In 7 patients an additional tumor resection was required, in 5 patients the tumor was assessed as inoperable, and in total in 5 patients an intraoperative RFA (4/5) or postoperative RITA (1/5) was required.Regarding procedural input, there was only a slight, but significant difference between the transport and set-up times before the intraoperative use (mean: 14 min 22 s) and the return transport (mean 13 min 6 s), (p = 0,038). The average examination time was 14 minutes, which makes only one third of the overall time demand.

CONCLUSION

Combination of IOUS with CEUS and elastography in oncological HPB surgery provides valuable information that affects surgical decision-making. The procedural input of about 45 minutes seems to be a good investment considering the improvement of the surgical procedure and a significant modification of the therapy approach in the majority of the cases.

Imaging Features of Fibrolamellar Hepatocellular Carcinoma with Contrast-Enhanced Ultrasound

PURPOSE

 Fibrolamellar hepatocellular carcinoma (f-HCC) is a rare primary liver tumor. Imaging plays an important role in diagnosis. The aim of this retrospective study was to analyze contrast-enhanced ultrasound (CEUS) features of histologically proven f-HCC in comparison to benign focal nodular hyperplasia (FNH).

MATERIALS & METHODS

 16 patients with histologically proven f-HCC lesions and 30 patients with FNH lesions were retrospectively reviewed regarding CEUS features to determine the malignant or benign nature of the focal liver lesions (FLL). Five radiologists assessed the CEUS enhancement pattern and came to a consensus using the EFSUMB (European Federation of Societies for Ultrasound in Medicine and Biology) guideline criteria.

RESULTS

 Fibrolamellar hepatocellular carcinoma manifested as a single and huge FLL. On CEUS, f-HCC showed heterogeneous hyperenhancement in the arterial phase and hypoenhancement (16/16, 100 %) in the portal venous and late phases (PVLP) as a sign of malignancy. In contrast to the hypoenhancement of f-HCC in the PVLP, all patients with FNH showed hyperenhancement as the most distinctive feature (P < 0.01). 8 f-HCC lesions showed a central scar as an unenhanced area (8/16, 50.0 %), which could also be detected in 53.3 % (16/30) of FNH lesions (P > 0.05).

CONCLUSION

 By analyzing the hypoenhancement in the PVLP, CEUS imaging reliably diagnosed f-HCC as a malignant FLL. CEUS also showed differentiation between f-HCC and FNH lesions, showing similar non-enhanced central scars, whereas f-HCC lesions showed peripheral hyperenhancement in the arterial phase and early washout in the PVLP.

What factors predict physicians' utilization behavior of contrast-enhanced ultrasound? Evidence from the integration of the Theory of Planned Behavior and Technology Acceptance Model using a structural equation modeling approach

BACKGROUND

The promotion of early diagnosis is undoubtedly effective in reducing the burden of disease. Contrast-enhanced ultrasound (CEUS) is a diagnostic technology for liver cancer, but its implementation faces some challenges. Understanding the influencing factors of CEUS utilization is crucial for its successful implementation. However, such research is rare. The aims of this study were to investigate the status of CEUS utilization and its predictors in China.

METHODS

Through multistage random sampling, a cross-sectional study design was conducted among physicians in charge of direct use of CEUS working at liver disease-related departments of sampled health institutions. To access the potential influencing factors of physicians' CEUS utilization, a structured questionnaire was developed based on the theoretical model, which was developed by integration of the Theory of Planned Behavior (TPB) and Technology Acceptance Model (TAM). Structural equation modeling was used to verify the proposed hypotheses, and analyze the relationship and mechanism between the factors.

RESULTS

A total of 309 physicians were enrolled. The mean score of utilization behavior was 2.04 (SD = 1.07), and 37.22% above the mean. The favorable fitting results demonstrated that the integration of TAM and TPB was an acceptable model. SEM results also identified physicians' intentions to use CEUS was directly associated with utilization behavior (β = 0.287, P < 0.001). Attitude (β = 0.272, P < 0.001), subjective norm (β = 0.172, P = 0.013), perceived behavioral control (β = 0.491, P < 0.001) and perceived usefulness (β = 0.108, P = 0.027) significantly influenced physicians' intentions. Besides, subjective norm (β = 0.065, P = 0.021), perceived behavioral control (β = 0.141, P = 0.003), and perceived ease of use (β = 0.022, P = 0.033) indirectly affected physicians' CEUS utilization.

CONCLUSIONS

The findings provide a reference for understanding the factors associated with physicians' utilization of CEUS. Additionally, the proposed measures such as building innovative and incentive environment, providing high quality and adequate training, etc., will help promote the utilization of CEUS, thereby increasing the detection rate of liver cancer, and improving the survival rate and the quality of life for liver cancer patients.

Potential application of dynamic contrast enhanced ultrasound in predicting microvascular invasion of hepatocellular carcinoma

OBJECTIVE

To investigate the clinical value of dynamic contrast enhanced ultrasound (D-CEUS) in predicting the microvascular invasion (MVI) of hepatocellular carcinoma (HCC).

PATIENTS AND METHODS

In this retrospective study, 16 patients with surgery and histopathologically proved HCC lesions were included. Patients were classified according to the presence of MVI: MVI positive group (n = 6) and MVI negative group (n = 10). Contrast enhanced ultrasound (CEUS) examinations were performed within a week before surgery. Dynamic analysis was performed by VueBox® software (Bracco, Italy). Three regions of interests (ROIs) were set in the center of HCC lesions, at the margin of HCC lesions and in the surrounding liver parenchyma accordingly. Time intensity curves (TICs) were generated and quantitative perfusion parameters including WiR (wash-in rate), WoR (wash-out rate), WiAUC (wash-in area under the curve), WoAUC (wash-out area under the curve) and WiPi (wash-in perfusion index) were obtained and analyzed.

RESULTS

All of HCC lesions showed arterial hyperenhancement (100 %) and at the late phase as hypoenhancement (75%) in CEUS. Among all CEUS quantitative parameters, the WiAUC and WoAUC were higher in MVI positive group than in MVI negative group in the center HCC lesions (P < 0.05), WiAUC, WoAUC and WiPI were higher in MVI positive group than in MVI negative group at the margin of HCC lesions. WiR and WoR were significant higher in MVI positive group.

CONCLUSIONS

D-CEUS with quantitative perfusion analysis has potential clinical value in predicting the existence of MVI in HCC lesions.

Is There a Place for Elastography in the Diagnosis of Hepatocellular Carcinoma?

Background and Aims: Elastography can provide information regarding tissue stiffness (TS). This study aimed to analyze the elastographic features of hepatocellular carcinoma (HCC) and the factors that influence intratumoral elastographic variability in patients with liver cirrhosis. Methods: This prospective study included 115 patients with liver cirrhosis and hepatocellular carcinoma evaluated between June 2016–November 2019. A total of 88 HCC nodules visualized in conventional abdominal ultrasound (US) met the inclusion criteria and underwent elastographic evaluation. Elastographic measurements (EM) were performed in HCC and liver parenchyma using VTQ (Virtual Touch Quantification), a point shear wave elastography (pSWE) technique. In all patients, we performed contrast-enhanced ultrasound (CEUS), and the final diagnosis of HCC was established by contrast-enhanced-CT or contrast-enhanced-MRI. Results: The mean VTQ values in HCCs were 2.16 ± 0.75 m/s. TS was significantly lower in HCCs than in the surrounding liver parenchyma 2.16 ± 0.75 m/s vs. 2.78 ± 0.92 (p < 0.001). We did not find significant differences between the first five and the last five EM, and the intra-observer reproducibility was excellent ICC: 0.902 (95% CI: 0.87–0.950). However, the tumor size, heterogeneity, and depth correlated with higher intralesional stiffness variability (p < 0.001). Conclusions: VTQ brings additional information for HCC characterization. Intra-observer reproducibility for both HCC and liver parenchyma was excellent. Knowing the stiffness of HCC’s might endorse an algorithm-based approach towards focal liver lesions (FLLs) in liver cirrhosis.

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.

Management consensus guideline for hepatocellular carcinoma: 2020 update on surveillance, diagnosis, and systemic treatment by the Taiwan Liver Cancer Association and the Gastroenterological Society of Taiwan

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related mortality in Taiwan. The Taiwan Liver Cancer Association and the Gastroenterological Society of Taiwan had established a management consensus guideline in 2016. The current recommendations focus on updating critical issues regarding the management of HCC, including surveillance, diagnosis, and systemic treatment. For surveillance, the updated guideline suggests the role of dynamic computed tomography or magnetic resonance imaging and contrast-enhanced ultrasound (CEUS) in selected patients. For diagnosis, this update incorporates CEUS and recognizes the role of gadoxetic acid-enhanced magnetic resonance imaging. For systemic therapy, the updated guideline summarizes the multiple choices of targeted therapy, immune checkpoint inhibitors, and the combination of both. Through this update of the management consensus guideline, patients with HCC can benefit from receiving optimal diagnostic and therapeutic modalities.

Paediatric gastrointestinal and hepatobiliary radiology: why do we need subspecialists, and what is new?

We present the case for subspecialisation in paediatric gastrointestinal and hepato-pancreatico-biliary radiology. We frame the discussion around a number of questions: What is different about the paediatric patient and paediatric gastrointestinal system? What does the radiologist need to do differently? And finally, what can be translated from these subspecialty areas into everyday practice? We cover conditions that the sub-specialist might encounter, focusing on entities such as inflammatory bowel disease and hepatic vascular anomalies. We also highlight novel imaging techniques that are a focus of research in the subspecialties, including contrast-enhanced ultrasound, MRI motility, magnetisation transfer factor, and magnetic resonance elastography.

Congenital heart disease-associated liver disease: a narrative review

Congenital heart diseases (CHD) can be associated with liver dysfunction. The cause for liver impairment can result out of a wide spectrum of different causes, including liver congestion, hypoxemia or low cardiac output. Fortunately, most CHD show a good long-term outcome from a cardiac perspective, but great attention should be paid on non-cardiac health problems that develop frequently in patients suffering from CHD. The treatment of liver dysfunction in CHD requires a close multidisciplinary management in a vulnerable patient collective. Unfortunately, structured recommendations on the management of liver dysfunction in patients with CHD are scarce. The objective of this review is to provide insights on the pathophysiology and etiologies of liver dysfunction as one of the most relevant non-cardiac problems related to CHD. Furthermore, we advise here on the management of liver disease in CHD with special attention on assessment of liver dysfunction, management of portal hypertension as well as on surveillance and management of hepatocellular carcinoma (HCC). A multidisciplinary perspective may help to optimize morbidity and mortality in the long-term course in these patients. However, as evidence is low in many aspects, we encourage the scientific community to perform prospective studies to gain more insights in the treatment of liver dysfunction in patients with CHD.

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

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

[A supposed hepatocellular adenoma turns out to be intrahepatic splenosis - a case report]

We report the case of a 62-year-old Caucasian male patient who presented with epigastric pain to our outpatient clinic. On abdominal ultrasound we detected a 26 mm oval hypoechoic lesion in segment 2 of the left liver lobe. Performing contrast-enhanced ultrasound this lesion showed an arterial hypervascularization with centripetal filling and a spoke wheel pattern. Due to a hyperenhancement during the portal and late phase this lesion led to the diagnosis of a benign liver tumor, probably a hepatocellular adenoma (HCA). As focal nodular hyperplasia (FNH) was still another possible diagnosis, we decided to perform an MRI, which could not differentiate between HCA and hepatocellular carcinoma (HCC). Therefore, we performed liver biopsy of this lesion. Histology and immunohistochemistry led to the final diagnosis of intrahepatic splenosis. Reassessment of patient history revealed an abdominal trauma with splenic rupture 5 years ago. Intrahepatic splenosis should be considered as an important differential diagnosis in patients with unknown liver tumor and a history of splenic trauma.

Contrast-enhanced ultrasound of benign and malignant liver lesions in children

Contrast-enhanced ultrasound (CEUS) is increasingly being used in children. One of the most common referrals for CEUS performance is characterization of indeterminate focal liver lesions and follow-up of known liver lesions. In this setting, CEUS is performed with intravenous administration of ultrasound contrast agents (UCAs). When injected into a vein, UCA microbubbles remain confined within the vascular network until they dissipate. Therefore, visualization of UCA within the tissues and lesions corresponds to true blood flow. CEUS enables continuous, real-time observation of the enhancement pattern of a focal liver lesion, allowing in most cases for a definite diagnosis and obviating the need for further cross-sectional imaging or other interventional procedures. The recent approval of Lumason (Bracco Diagnostics, Monroe Township, NJ) for pediatric liver CEUS applications has spurred the widespread use of CEUS. In this review article we describe the role of CEUS in pediatric liver applications, focusing on the examination technique and interpretation of main imaging findings of the most commonly encountered benign and malignant focal liver lesions. We also compare the diagnostic performance of CEUS with other imaging modalities for accurate characterization of focal liver lesions.

Diagnostic Value of CEUS Prompting Liver Biopsy: Histopathological Correlation of Hepatic Lesions with Ambiguous Imaging Characteristics

Background: Contrast-enhanced ultrasound (CEUS) allows for dynamic analysis of vascularization patterns of unclear hepatic lesions. Our study aimed to evaluate the diagnostic performance of CEUS for further characterizing suspicious liver lesions by comparing findings from CEUS examinations with corresponding histopathology. Methods: Between 2005 and 2016, 160 patients with unclear liver lesions underwent CEUS followed by liver biopsy. All examinations were performed by an experienced consultant radiologist (EFSUMB Level 3) and included native B-mode ultrasound, Color Doppler, and CEUS. A second-generation blood pool contrast agent was applied for CEUS. Results: CEUS was successfully performed in all patients without occurrence of any adverse side effects. CEUS showed a sensitivity of 94.5%, a specificity of 70.6%, a true positive rate of 87.3%, and a true negative rate of 85.7% compared to histopathological results as the reference standard. Conclusions: CEUS represents a safe imaging modality with a high diagnostic accuracy in assessing both—benign and malignant—liver lesions compared to corresponding histopathological results.

[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.

Diagnostic Accuracy of Contrast-Enhanced Ultrasound Liver Imaging Reporting and Data System (CEUS LI-RADS) for Differentiating Between Hepatocellular Carcinoma and Other Hepatic Malignancies in High-Risk Patients: A Meta-Analysis

OBJECTIVES

 The American College of Radiology (ACR) contrast-enhanced ultrasound liver imaging reporting and data system (CEUS LI-RADS), which includes diagnostic criteria for hepatocellular carcinoma (HCC) and other hepatic malignancies (OM), is increasingly used in clinical practice. This study performed a meta-analysis to assess the diagnostic accuracy of CEUS LI-RADS for differentiating between HCC and OM in high-risk patients.

METHODS

 PubMed, Embase (Ovid), and Cochrane (CENTRAL) were searched for relevant studies. All studies that reported the percentage of HCC and OM in the LI-RADS categories were included. Random-effects models were used to calculate the pooled sensitivity and specificity, diagnostic odds ratio (DOR), and summary receiver operating characteristic (SROC) curve.

RESULTS

 Eight studies involving 4215 focal liver lesions were included in the final analysis. The pooled sensitivity and specificity of the LR-5 criteria for HCC were 0.71 (95 % CI, 0.69-0.72) and 0.88 (0.85-0.91), respectively, the DOR was 18.36 (7.41-45.52), and the area under the SROC curve (AUC) was 0.8128. The pooled sensitivity and specificity of the LR-M criteria for OMs were 0.85 (0.81-0.88) and 0.86 (0.85-0.87), the DOR was 27.82 (11.83-65.40), respectively, and the SROC AUC was 0.9098.

CONCLUSION

 The CEUS LI-RADS can effectively distinguish HCC from other hepatic malignancy in high-risk patients based on LR-5 criteria and LR-M criteria. However, further studies are needed for validation due to the limited number of included studies and the potential heterogeneity among the included studies.

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.

Advanced Fusion Imaging and Contrast-Enhanced Imaging (CT/MRI-CEUS) in Oncology

Simple Summary

Fusion imaging depicts an innovative technique by which previously performed computed tomography/magnetic resonance imaging can be integrated and reconstructed with advanced contrast-enhanced ultrasound using modern ultrasound devices in a real-time manner. Fusion imaging allows for complementing strengths and reducing restrictions of the combined imaging modalities. The visualization of parenchymal and tumoral microperfusion by contrast-enhanced ultrasound can be dynamically fused and assessed with images from previous cross-sectional studies and may help to decipher underlying entities of indeterminate lesions or validate suspicious morphology. The findings from our study demonstrate the benefits of fusion imaging for evaluating focal hepatic and renal lesions. The excellent safety profile, accessibility, repeatability and cost-effectiveness are advantages of fusion imaging which make it a powerful diagnostic tool for the modern radiologist.

Abstract

Fusion imaging depicts an innovative technique that facilitates combining assets and reducing restrictions of advanced ultrasound and cross-sectional imaging. The purpose of the present retrospective study was to evaluate the role of fusion imaging for assessing hepatic and renal lesions. Between 02/2011–08/2020, 92 patients in total were included in the study, of which 32 patients had hepatic lesions, 60 patients had renal lesions. Fusion imaging was technically successful in all patients. No adverse side effects upon intravenous (i.v.) application of SonoVue^® (Bracco, Milan, Italy) were registered. Fusion imaging could clarify all 11 (100%) initially as indeterminate described hepatic lesions by computed tomography/magnetic resonance imaging (CT/MRI). Moreover, 5/14 (36%) initially suspicious hepatic lesions could be validated by fusion imaging, whereas in 8/14 (57%), malignant morphology was disproved. Moreover, fusion imaging allowed for the clarification of 29/30 (97%) renal lesions initially characterized as suspicious by CT/MRI, of which 19/30 (63%) underwent renal surgery, histopathology revealed malignancy in 16/19 (84%), and benignity in 3/19 (16%). Indeterminate findings could be elucidated by fusion imaging in 20/20 (100%) renal lesions. Its accessibility and repeatability, even during pregnancy and in childhood, its cost-effectiveness, and its excellent safety profile, make fusion imaging a promising instrument for the thorough evaluation of hepatic and renal lesions in the future.

Contrast-Enhanced Ultrasonography as a Novel Method for the Dynamic Visualization of Blood Flow and Fiber Blockage in Dialyzers: A Feasibility Study

The capillary dialyzer represents the central element of the extracorporeal blood circuit of a therapy system for hemodialysis. The aim of this study was to assess the blood-flow characteristics of dialyzers with the help of modern ultrasound techniques. Five brand-new dialyzers (FX80 classix, Fresenius Medical Care, Bad Homburg, Germany) and five dialyzers after a dialysis session were analyzed by different ultrasound techniques to detect functional and structural changes. B-mode and Doppler techniques were not suitable to describe differences in brand-new and clinically applied dialyzers. Contrast-enhanced ultrasonography, however, was able to visualize blood-flow profiles in the capillaries. Although dialyzers displayed no signs of clinical dysfunction, contrast-enhanced ultrasonography was able to detect blocked capillaries of varying degrees after a dialysis session in all five examined dialyzers. Consequently, the blood-flow velocity was higher in the remaining unblocked capillaries in comparison to the velocity in the brand-new dialyzers. This information may be helpful for improving the geometric design of dialyzers, including their capillary membranes, and optimizing anti-coagulation strategies in hemodialysis patients.

Diagnostic Value of High Frame Rate Contrast-enhanced Ultrasonography and Post-processing Contrast Vector Imaging for Evaluation of Focal Liver Lesions: A Feasibility Study

This study evaluated the feasibility of contrast vector imaging (CVI) to characterize focal liver lesions. From July to October 2019, we prospectively enrolled 30 patients with focal liver lesions (hepatocellular carcinoma [HCC] [n = 19], metastasis [n = 8], combined HCC-cholangiocarcinoma [CC] [n = 1], intra-hepatic CC [n = 1] and sclerosed hemangioma [n = 1]). Contrast-enhanced ultrasound (CEUS) was performed with high frame rate contrast harmonic imaging technique by one radiologist, and post-processing CVI was obtained and analyzed by two radiologists. On combined CVI with CEUS, the staining pattern was significantly predominant in HCCs (9/11, 81.8%), while peripheral rim was frequent in non-HCCs (5/8, 62.5%) (p = 0.020). HCCs exhibited feeding arteries (8/11, 45.5%) and high velocity variance (10/11, 90.9 %), whereas non-HCCs showed detour pattern (4/8, 50.0%) with either a high or low velocity variance (4/8, 50.0%, both), with no significant inter-group differences (p = 0.052 and 0.080, respectively). In conclusion, CVI was feasible and provided quantitative and multi-parametric information of different types of hepatic tumors.

Ultrasound 2020 - Diagnostics & Therapy: On the Way to Multimodal Ultrasound: Contrast-Enhanced Ultrasound (CEUS), Microvascular Doppler Techniques, Fusion Imaging, Sonoelastography, Interventional Sonography

BACKGROUND

 Ultrasound as a non-ionizing imaging procedure is one of the most important diagnostic procedures in everyday clinical practice. The technology is widely used. Due to constant technical innovations, sonographic procedures, such as contrast-enhanced ultrasound (CEUS), sonoelastography, new microvascular Doppler modalities and, as an example of interventional procedures, sonographically controlled microwave ablation (MWA), are becoming increasingly important in diagnostic imaging and interventional medicine alongside CT and MRI. However, this also requires greater expertise, specialization and qualification on the part of users.

METHOD

 This review article provides information about the range of technical innovations in ultrasound in recent years and describes the underlying technology, the clinical applications, and their diagnostic value. These are presented in the context of the current literature, explaining their advantages and disadvantages and their clinical value.

RESULTS AND CONCLUSION

 Contrast-enhanced ultrasound (CEUS), microvascular Doppler modalities, fusion imaging and elastography complement B-scan ultrasound and conventional Doppler procedures for various problems. Microwave ablation (MWA) has a firm place as an ablative procedure for local tumor therapy in different organ systems and can be performed under ultrasound guidance. Thanks to new developments, the possibilities of ultrasound are now greater than ever. Knowledge of the technology, indications, and possible applications of newer procedures is essential for adequate patient care.

KEY POINTS

  · Contrast-enhanced ultrasound (CEUS) allows an increase in sensitivity and specificity in the assessment of parenchymal lesions.. · CEUS allows the microperfusion to be visualized and quantified. For larger vessels, CEUS is an important instrument in diagnosing endoleak after stenting.. · Microvascular Doppler techniques with clutter suppression algorithms allow a more accurate representation of the smallest vessels than regular color or power Doppler.. · Elastography of the liver in diffuse hepatopathies is a noninvasive diagnostic tool to exclude higher grade fibrosis/cirrhosis.. · Microwave ablation (MWA) also offers sonographically controlled ablation of tumors..

CITATION FORMAT

· Kloth C, Kratzer W, Schmidberger J et al. Ultrasound 2020 - Diagnostics & Therapy: On the Way to Multimodal Ultrasound: Contrast-Enhanced Ultrasound (CEUS), Microvascular Doppler Techniques, Fusion Imaging, Sonoelastography, Interventional Sonography . Fortschr Röntgenstr 2021; 193: 23 - 32.