Contrast-enhanced ultrasound liver imaging reporting and data system: clinical validation in a prospective multinational study in North America and Europe

BACKGROUND AND AIMS

The objective of this study is to determine the diagnostic accuracy of the American College of Radiology Contrast-Enhanced Ultrasound (CEUS) Liver Imaging Reporting and Data System LR-5 characterization for HCC diagnosis in North American or European patients.

APPROACH AND RESULTS

A prospective multinational cohort study was performed from January 2018 through November 2022 at 11 academic and nonacademic centers in North America and Europe. Patients at risk for HCC with at least 1 liver observation not previously treated, identified on ultrasound (US), or multiphase CT or MRI performed as a part of standard clinical care were eligible for the study. All participants were examined with CEUS of the liver within 4 weeks of CT/MRI or tissue diagnosis to characterize up to 2 liver nodules per participant using ACR CEUS Liver Imaging Reporting and Data System. Definite HCC diagnosis on the initial CT/MRI, imaging follow-up, or histology for CT/MRI-indeterminate nodules were used as reference standards. A total of 545 nodules had confirmed reference standards in 480 patients, 73.8% were HCC, 5.5% were other malignancies, and 20.7% were nonmalignant. The specificity of CEUS LR-5 for HCC was 95.1% (95% CI 90.1%-97.7%), sensitivity 62.9% (95% CI 57.9%-67.7%), positive predictive value 97.3% (95% CI 94.5%-98.7%), and negative predictive value 47.7% (95% CI 41.7%-53.8%). In addition, benign CEUS characterization (LR-1 or LR-2) had 100% specificity and 100% positive predictive value for nonmalignant liver nodules.

CONCLUSIONS

CEUS Liver Imaging Reporting and Data System provides an accurate categorization of liver nodules in participants at risk for HCC.

Diversity of current ultrasound practice within and outside radiology departments with a vision for 20 years into the future: a position paper of the ESR ultrasound subcommittee

Ultrasound practice is a longstanding tradition for radiology departments, being part of the family of imaging techniques. Ultrasound is widely practiced by non-radiologists but becoming less popular within radiology. The position of ultrasound in radiology is reviewed, and a possible long-term solution to manage radiologist expectations is proposed. An international group of experts in the practice of ultrasound was invited to describe the current organisation of ultrasound within the radiology departments in their own countries and comment on the interaction with non-radiologists and training arrangements. Issues related to regulation, non-medical practitioners, and training principles are detailed. A consensus view was sought from the experts regarding the position of ultrasound within radiology, with the vision of the best scenario for the continuing dominance of radiologists practising ultrasound. Comments were collated from nine different countries. Variable levels of training, practice, and interaction with non-radiologist were reported, with some countries relying on non-physician input to manage the service. All experts recognised there was a diminished desire to practice ultrasound by radiologists. Models varied from practising solely ultrasound and no other imaging techniques to radiology departments being central to the practice of ultrasound by radiologists and non-radiologist, housed within radiology. The consensus view was that the model favoured in select hospitals in Germany would be the most likely setup for ultrasound radiologist to develop and maintain practice. The vision for 20 years hence is for a central ultrasound section within radiology, headed by a trained expert radiologist, with non-radiologist using the facilities.Critical relevance statement The future of ultrasound within the radiology department should encompass all ultrasound users, with radiologists expert in ultrasound, managing the ultrasound section within the radiology department. The current radiology trainees must learn of the importance of ultrasound as a component of the 'holistic' imaging of the patient.Key points: 1. Ultrasound imaging within radiology departments precedes the introduction of CT and MR imaging and was first used over 50 years ago.2. Non-radiology practitioners deploy ultrasound examinations to either 'problem solve' or perform a comprehensive ultrasound examination; radiologists provide comprehensive examinations or use ultrasound to direct interventional procedures.3. Radiology does not 'own' ultrasound, but radiologists are best placed to offer a comprehensive patient-focused imaging assessment.4. A vision of the future of ultrasound within the radiology department is encompassing all ultrasound users under radiologists who are experts in ultrasound, positioned within the radiology department.5. The current radiology trainee must be aware of the importance of ultrasound as a component of the 'holistic' imaging of the patient.

Assessment of arterial-phase hyperenhancement and late-phase washout of hepatocellular carcinoma-a meta-analysis of contrast-enhanced ultrasound (CEUS) with SonoVue® and Sonazoid®

OBJECTIVES

The recognition of arterial phase hyperenhancement (APHE) and washout during the late phase is key for correct diagnosis of hepatocellular carcinoma (HCC) with contrast-enhanced ultrasound (CEUS). This meta-analysis was conducted to compare SonoVue®-enhanced and Sonazoid®-enhanced ultrasound in the assessment of HCC enhancement and diagnosis.

METHODS

Studies were included in the analysis if they reported data for HCC enhancement in the arterial phase and late phase for SonoVue® or in the arterial phase and Kupffer phase (KP) for Sonazoid®. Forty-two studies (7502 patients) with use of SonoVue® and 30 studies (2391 patients) with use of Sonazoid® were identified. In a pooled analysis, the comparison between SonoVue® and Sonazoid® CEUS was performed using chi-square test. An inverse variance weighted random-effect model was used to estimate proportion, sensitivity, and specificity along with 95% confidence interval (CI).

RESULTS

In the meta-analysis, the proportion of HCC showing APHE with SonoVue®, 93% (95% CI 91-95%), was significantly higher than the proportion of HCC showing APHE with Sonazoid®, 77% (71-83%) (p < 0.0001); similarly, the proportion of HCC showing washout at late phase/KP was significantly higher with SonoVue®, 86% (83-89%), than with Sonazoid®, 76% (70-82%) (p < 0.0001). The sensitivity and specificity for the detection of APHE plus late-phase/KP washout detection in HCC were also higher with SonoVue® than with Sonazoid® (sensitivity 80% vs 52%; specificity 80% vs 73% in studies within unselected patient populations).

CONCLUSION

APHE and late washout in HCC are more frequently observed with SonoVue® than with Sonazoid®. This may affect the diagnostic performance of CEUS in the diagnosis of HCCs.

CLINICAL RELEVANCE STATEMENT

Meta-analysis data show the presence of key enhancement features for diagnosis of hepatocellular carcinoma is different between ultrasound contrast agents, and arterial hyperenhancement and late washout are more frequently observed at contrast-enhanced ultrasound with SonoVue® than with Sonazoid®.

KEY POINTS

• Dynamic enhancement features are key for imaging-based diagnosis of HCC. • Arterial hyperenhancement and late washout are more often observed in HCCs using SonoVue®-enhanced US than with Sonazoid®. • The existing evidence for contrast-enhanced US may need to be considered being specific to the individual contrast agent.

Multiparametric Ultrasound for Diagnosing Testicular Lesions: Everything You Need to Know in Daily Clinical Practice

BACKGROUND

Ultrasonography (US) represents the gold standard imaging method for the assessment of testicular lesions (TL). The gray-scale (GSUS) and color-Doppler (CDUS) ultrasound examination allow sonographers to investigate the size, margins, echotexture, and vascular features of TLs with the aim to differentiate benign from malignant lesions. Recently, the use of contrast-enhanced US (CEUS) and sonoelastography (SE) has led to further improvements in the differential diagnosis of TL. Although GSUS and CDUS are often sufficient to suggest the benign or malignant nature of the TL, CEUS can be decisive in the differential diagnosis of unclear findings, while SE can help to strengthen the diagnosis. The contemporary combination of GSUS, CDUS, CEUS, and SE has led to a new diagnostic paradigm named multiparametric US (mp-US), which is able to provide a more detailed characterization of TLs than single techniques alone. This narrative and pictorial review aimed to describe the mp-US appearance of several TLs.

METHODS

An extensive Medline search was performed to identify studies in the English language focusing on the mp-US evaluation of TLs.

RESULTS

A practical mp-US "identity card" and iconographic characterization of several benign and malignant TLs is provided herein.

CONCLUSIONS

The mp-US characterization of TL reported herein can be useful in daily clinical practice.

Ultrasonic Sound Speed Estimation for Liver Fat Quantification: A Review by the AIUM-RSNA QIBA Pulse-Echo Quantitative Ultrasound Initiative

Non-alcoholic fatty liver disease (NAFLD) is a significant cause of diffuse liver disease, morbidity and mortality worldwide. Early and accurate diagnosis of NALFD is critical to identify patients at risk of disease progression. Liver biopsy is the current gold standard for diagnosis and prognosis. However, a non-invasive diagnostic tool is desired because of the high cost and risk of complications of tissue sampling. Medical ultrasound is a safe, inexpensive and widely available imaging tool for diagnosing NAFLD. Emerging sonographic tools to quantitatively estimate hepatic fat fraction, such as tissue sound speed estimation, are likely to improve diagnostic accuracy, precision and reproducibility compared with existing qualitative and semi-quantitative techniques. Various pulse-echo ultrasound speed of sound estimation methodologies have been investigated, and some have been recently commercialized. We review state-of-the-art in vivo speed of sound estimation techniques, including their advantages, limitations, technical sources of variability, biological confounders and existing commercial implementations. We report the expected range of hepatic speed of sound as a function of liver steatosis and fibrosis that may be encountered in clinical practice. Ongoing efforts seek to quantify sound speed measurement accuracy and precision to inform threshold development around meaningful differences in fat fraction and between sequential measurements.

Utility of contrast enhanced ultrasound (CEUS) in penile trauma

Penile traumatic injuries are rare with potentially severe consequences, with clinical assessment challenging due to pain and swelling. Ultrasound is the primary imaging modality for assessing the penis. It has a high spatial resolution and rapid availability and is portable. Contrast enhanced ultrasound is an advanced ultrasound technique that adds real-time dynamic vascular imaging safely, increasing diagnostic precision and confidence, allowing for better therapeutic management of traumatic penile injuries. Contrast enhanced ultrasound helps to delineate the extent of a haematoma, distinguishing this from the herniated corpus cavernosum, detecting the point of rupture of the tunica albuginea, showing vascular abnormalities, localising a dislocated penis and determining penile viability. The integrity of the urethra may be assessed with intracavitary contrast enhanced ultrasound. Additionally, contrast enhanced ultrasound allows monitoring of the response to endovascular and surgical treatment. This review aims to detail the anatomy and pathogenesis of penile trauma, to give guidance on optimising the contrast enhanced ultrasound technique and to obtain diagnostic examinations. Illustration of the spectrum of aspects of penile trauma will be complemented with a literature review.Critical relevance statement Contrast enhanced ultrasound is a safe and efficient imaging modality that allows for highly accurate diagnoses, helping achieve more successful and conservative treatments of penile trauma complications.Key points• Ultrasound is an accurate and safe imaging test for penile trauma.• CEUS adds dynamic vascular imaging in real-time increasing diagnostic confidence.• CEUS can delineate penile haematomas, locate fractures and demonstrate vessel integrity.• CEUS potentially allows for more conservative treatment of penile trauma complications.

Ultrasound simulation training to meet the 2021 Royal College of Radiologists' curriculum for radiology trainees: South East London experience

AIM

To enhance ultrasound teaching delivery to radiology trainees using a simulation course matched to the 2021 Royal College of Radiologists (RCR) curriculum.

MATERIAL AND METHODS

An ultrasound simulation training course was designed for specialty trainees (ST) 1 in radiology, which was based on the 2021 RCR curriculum and covered the top ultrasound training priorities. The course was piloted initially on two occasions in a 1-day format to the August 2021 and the March 2022 ST1 intake trainees. Based on the feedback, a comprehensive 4-day course was developed and delivered between October and December 2022 for the August 2022 ST1 intake, funded by Health Education England. The outcomes measured were subjective trainee feedback using numerical scores and free text.

RESULTS

All King's College Hospital NHS Foundation Trust radiology ST1 trainees from the August 2021 to the August 2022 intake participated in ultrasound simulation training. The training matched the RCR curriculum and increased the trainees' confidence and competency in medical ultrasound.

CONCLUSIONS

Ultrasound simulation training can be successfully delivered to ST1 trainees to match the 2021 RCR curriculum and enhance training in medical ultrasound for radiologists.

EFSUMB Clinical Practice Guidelines for Point-of-Care Ultrasound: Part One (Common Heart and Pulmonary Applications) SHORT VERSION

OBJECTIVE

 To evaluate the evidence and produce a summary and recommendations for the most common heart and lung point-of-care ultrasound (PoCUS).

METHODS

 We reviewed 10 clinical domains/questions related to common heart and lung applications of PoCUS. Following review of the evidence, a summary and recommendations were produced, including assigning levels of evidence (LoE) and grading of recommendation, assessment, development, and evaluation (GRADE). 38 international experts, the expert review group (ERG), were invited to review the evidence presented for each question. A level of agreement of over 75 % was required to progress to the next section. The ERG then reviewed and indicated their level of agreement of the summary and recommendation for each question (using a 5-point Likert scale), which was approved in the case of a level of agreement of greater than 75 %. A level of agreement was defined as a summary of "strongly agree" and "agree" on the Likert scale responses.

FINDINGS AND RECOMMENDATIONS

 One question achieved a strong consensus for an assigned LoE of 3 and a weak GRADE recommendation (question 1), the remaining 9 questions achieved broad agreement with an assigned LoE of 4 and a weak GRADE recommendation (question 2), three achieved an LoE of 3 with a weak GRADE recommendation (questions 3-5), three achieved an LoE of 3 with a strong GRADE recommendation (questions 6-8) and the remaining two were assigned an LoE of 2 with a strong GRADE recommendation (questions 9 and 10).

CONCLUSION

 These consensus-derived recommendations should aid clinical practice and highlight areas of further research for PoCUS in acute settings.

EFSUMB Clinical Practice Guidelines for Point-of-Care Ultrasound: Part One (Common Heart and Pulmonary Applications) LONG VERSION

AIMS

 To evaluate the evidence and produce a summary and recommendations for the most common heart and lung applications of point-of-care ultrasound (PoCUS).

METHODS

 We reviewed 10 clinical domains/questions related to common heart and lung applications of PoCUS. Following review of the evidence, a summary and recommendation were produced, including assignment of levels of evidence (LoE) and grading of the recommendation, assessment, development, and evaluation (GRADE). 38 international experts, the expert review group (ERG), were invited to review the evidence presented for each question. A level of agreement of over 75 % was required to progress to the next section. The ERG then reviewed and indicated their level of agreement regarding the summary and recommendation for each question (using a 5-point Likert scale), which was approved if a level of agreement of greater than 75 % was reached. A level of agreement was defined as a summary of "strongly agree" and "agree" on the Likert scale responses.

FINDINGS AND RECOMMENDATIONS

 One question achieved a strong consensus for an assigned LoE of 3 and a weak GRADE recommendation (question 1). The remaining 9 questions achieved broad agreement with one assigned an LoE of 4 and weak GRADE recommendation (question 2), three achieving an LoE of 3 with a weak GRADE recommendation (questions 3-5), three achieved an LoE of 3 with a strong GRADE recommendation (questions 6-8), and the remaining two were assigned an LoE of 2 with a strong GRADE recommendation (questions 9 and 10).

CONCLUSION

 These consensus-derived recommendations should aid clinical practice and highlight areas of further research for PoCUS in acute settings.

Comparison Between Different Manufacturers' 2-D and Point Shear Wave Elastography Techniques in Staging Liver Fibrosis in Chronic Liver Disease Using Liver Biopsy as the Reference Standard: A Prospective Study

The purpose of this study was to assess the utility of 2-D shear wave elastography (SWE) in assessing liver fibrosis in patients with chronic liver disease by comparing its performance with that of point shear wave elastography (pSWE) using liver histological staging as the reference standard. In this ethics committee-approved, single-institution prospective study, pSWE and 2-D SWE velocity measurements were obtained in 121 adult patients (age: 18-70 y, median: 45 y) immediately before a liver biopsy for chronic liver disease. Shear wave velocity (SWV) and Ishak scores were compared using the Kruskal-Wallis test, Spearman's correlation and receiver operating characteristic (ROC) curve analysis. Youden's index was used to determine the optimal cutoff point. There was no technical failure using pSWE and 2-D SWE. The mean difference for SWV between pSWE and 2-D SWE was 0.0223 (limits of agreement: -1.1009, 1.1145). Values for both pSWE and 2-D SWE were significantly correlated with fibrosis stage (Spearman's ρ = 0.606, p < 0.0001; ρ = 0.722, p < 0.001 respectively). The area under the ROC curve differentiating F ≥3 was 0.855 (95% confidence interval: 0.778-0.932) for pSWE and 0.884 (95% CI: 0.817-0.951) for 2-D SWE. The AUC for differentiating F ≥5 was 0.890 (95% CI: 0.826-0.954) for pSWE and 0.926 (95% CI: 0.88-0.973) for 2-D SWE. This study indicates that 2-D SWE provides feasible and accurate assessment of liver fibrosis, comparable to that provided by pSWE from two different manufacturers' machines.

Professional Standards in Medical Ultrasound - EFSUMB Position Paper (Short Version) - General Aspects

This first position paper of the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) on professional standards presents a common position across the different medical professions within EFSUMB regarding optimal standards for the performing and reporting of ultrasound examinations by any professional ultrasound operator. It describes general aspects of professionality that ensure procedure quality, effectiveness, efficiency, and sustainability in virtually all application fields of medical ultrasound. Recommendations are given related to safety and indication of ultrasound examinations, requirements for examination rooms, structured examination, systematic reporting of results, and management, communication and archiving of ultrasound data. The print version of this article is a short version. The long version is published online.

Professional Standards in Medical Ultrasound - EFSUMB Position Paper (Long Version) - General Aspects

This first position paper of the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) on professional standards presents a common position across the different medical professions within EFSUMB regarding optimal standards for the performing and reporting of ultrasound examinations by any professional ultrasound operator. It describes general aspects of professionality that ensure procedure quality, effectiveness, efficiency, and sustainability in virtually all application fields of medical ultrasound. Recommendations are given related to safety and indication of ultrasound examinations, requirements for examination rooms, structured examination, systematic reporting of results, and management, communication and archiving of ultrasound data. The print version of this article is a short version. The long version is published online.

Contrast-enhanced US of Segmental Testicular Infarction

Online supplemental material is available for this article.

Point-of-care contrast enhanced lung ultrasound and COVID-19

OBJECTIVES

Bedside lung ultrasound has been indispensable during the coronavirus disease 2019 (COVID-19) pandemic, allowing us to rapidly assess critically unwell patients. We demonstrate the unique application of contrast-enhanced ultrasound with the aim of further understanding this disease.

METHODS

Patient demographics were recorded alongside recent cross-sectional imaging and inflammatory markers. Ultrasound was conducted by experienced operators in a portable setting. Conventional six-point lung ultrasound method was used to evaluate B-lines, small (subpleural) consolidation and the pleura. Areas of small consolidation were targeted after intravenous administration of ultrasound contrast.

RESULTS

The areas of small consolidations, a potential sign of pneumonia on B-mode lung ultrasound, usually enhance on contrast-enhanced ultrasound. Our study revealed these areas to be avascular, indicating an underlying thrombotic/infarction process. Findings were present in 100% of the patients we examined. We have also shown that the degree of infarction correlates with CT severity (r = 0.4) and inflammatory markers, and that these areas improve as patients recover.

CONCLUSIONS

We confirmed the theory of immune thrombus by identifying the presence of microthrombi in the lungs of 100% of our patients, despite 79% having had a recent negative CT pulmonary angiogram study. contrast-enhanced ultrasound can be utilised to add confidence to an uncertain COVID-19 diagnosis and for prognosticating and monitoring progress in confirmed COVID-19 patients. Contrast-enhanced ultrasound is clearly very different to CT, the gold standard, and while there are specific pathologies that can only be detected on CT, contrast-enhanced ultrasound has many advantages, most notability the ability to pick up microthrombi at the periphery of the lungs.

Development of and Gathering Validity Evidence for a Theoretical Test in Contrast-Enhanced Ultrasound

Contrast-enhanced ultrasound (CEUS) is an imaging modality applied in a broad field of medical specialties for diagnostic uses, guidance during biopsy procedures and ablation therapies and sonoporation therapy. Appropriate training and assessment of theoretical and practical competencies are recommended before practicing CEUS, but no validated assessment tools exist. This study was aimed at developing a theoretical multiple-choice question-based test for core CEUS competencies and gathering validity evidence for the test. An expert team developed the test via a Delphi process. The test was administered to medical doctors with varying CEUS experience, and the results were used to evaluate test items, internal-consistency reliability, ability to distinguish between different proficiency levels and to establish a pass/fail score. Validity evidence was gathered according to Messick's framework. The final test with 47 test items could distinguish between operators with and without CEUS experience with acceptable reliability. The pass/fail score led to considerable risk of false positives and negatives. The test may be used as an entry test before learning practical CEUS competencies but is not recommended for certification purposes because of the risk of false positives and negatives.

Multiparametric ultrasound imaging characteristics of multiple testicular adrenal rest tumours in congenital adrenal hyperplasia

INTRODUCTION

Testicular adrenal rest cell tumours (TART) are rare benign adrenocorticotropic hormone-dependent testicular tumours, which can develop in patients with congenital adrenal hyperplasia. If left untreated, they can cause testicular tissue damage and infertility. Ultrasound is the imaging modality of choice allowing for non-invasive diagnosis provided that characteristic features are seen. In recent times, magnetic resonance imaging characteristics have also been described to aid diagnosis.

CASE REPORT

This case describes the imaging features of multiple bilateral TART in a young patient with congenital adrenal hyperplasia. Traditional greyscale and colour Doppler ultrasound demonstrated intratesticular, predominantly hypoechoic areas, with increased surrounding colour Doppler flow. In addition, contrast-enhanced ultrasound and strain elastography were performed, showing increased TART vascularisation and increased stiffness in the hypoechoic areas. Subsequent magnetic resonance imaging confirmed bilateral lobulated, well demarcated, intratesticular lesions, which appeared predominantly isointense on T1-weighted imaging, hypointense on T2-weighted imaging, with heterogeneous enhancement following gadolinium administration.

DISCUSSION

This case illustrates the sonographic features including greyscale, colour Doppler, contrast and elastography ultrasound of TART in a patient with congenital adrenal hyperplasia. Both contrast-enhanced ultrasound and elastography can provide information about tissue properties not normally derived from conventional ultrasound and aid accurate diagnosis. Additional magnetic resonance imaging is not normally required with typical ultrasound appearances. The unusual findings seen on the ultrasound examination were likely secondary to poor compliance with treatment.

CONCLUSION

Familiarity and recognition of characteristic and uncommon imaging features of these tumours are important to avoid misdiagnosis and surgical intervention.

The role of lung ultrasound in COVID-19 disease

This statement summarises basic settings in lung ultrasonography and best practice recommendations for lung ultrasonography in COVID-19, representing the agreed consensus of experts from the Ultrasound Subcommittee of the European Society of Radiology (ESR). Standard lung settings and artefacts in lung ultrasonography are explained for education and training, equipment settings, documentation and self-protection.

European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB): An Update on the Pediatric CEUS Registry on Behalf of the "EFSUMB Pediatric CEUS Registry Working Group"

The European Federation of Ultrasound in Medicine and Biology (EFSUMB) created the "EFSUMB Pediatric Registry" (EFSUMB EPR) with the purpose of collecting data regarding the intravenous application of pediatric contrast-enhanced ultrasound (CEUS). The primary aim was to document the current clinical practice and usefulness of the technique and secondarily to assess CEUS safety in children. We issue the preliminary results of this database and examine the overall practice of CEUS in children in Europe.

Contrast-Enhanced Ultrasound Quantification Assessment of Focal Fatty Variations in Liver Parenchyma: Challenging the Traditional Qualitative Paradigm of Uniform Enhancement With Adjacent Parenchyma

OBJECTIVES

The purpose of this study was to quantify contrast-enhanced ultrasound enhancement of focal fatty sparing (FFS) and focal fatty infiltration (FFI) and compare it with adjacent liver parenchyma.

METHODS

This was a retrospective observational study yielding 42 cases in the last 4 years. Inclusion criteria were a focal liver lesion, adequate video availability, and an established diagnosis of FFS or FFI based on clinical or imaging follow-up or a second modality. Contrast-enhanced ultrasound examinations were performed with a standard low-mechanical index technique. Commercially available software calculated quantitative parameters for a focal liver lesion and a reference area of liver parenchyma, producing relative indices.

RESULTS

In total, 42 patients were analyzed (19 male) with a median age of 18 (interquartile range, 42) years and a median lesion diameter of 30 (interquartile range, 16) mm. The cohort included 26 with FFS and 16 with FFI. Subjectively assessed, 27% of FFS and 25% of FFI were hypoenhancing in the arterial phase, and 73% of FFS and 75% of FFI were isoenhancing. In the venous and delayed phases, all lesions were isoenhancing. The peak enhancement (P = .001), wash-in area under the curve (P < .01), wash-in rate (P = .023), and wash-in perfusion index (P = .001) were significantly lower in FFS compared with adjacent parenchyma but not the mean transit time. In the FFI subgroup, no significant difference was detected. Comparing relative parameters, only the wash-in rate was significantly (P = .049) lower in FFS than FFI. The mean follow-up was 2.8 years.

CONCLUSIONS

Focal fatty sparing shows significantly lower and slower enhancement than the liver parenchyma, whereas FFI enhances identically. Focal fatty sparing had a significantly slower enhancement than FFI.

Paediatric focal nodular hyperplasia: A case study of typical contrast-enhanced ultrasound findings with quantitative analysis and correlated with magnetic resonance imaging

Introduction

Focal nodular hyperplasia, a benign liver tumour, is the second most common focal benign liver lesion, after a cavernous haemangioma. Contrast-enhanced ultrasound is used increasingly for the diagnostic work up and follow-up of focal liver lesions in adults, but is particularly valuable in the paediatric population, with the ability to reduce radiation and the nephrotoxic contrast agents used in computed tomography or magnetic resonance imaging. Confident recognition of focal nodular hyperplasia is important; it is benign, usually asymptomatic, of no clinical significance, of no clinical consequence or malignant potential. We present a case of focal nodular hyperplasia of the liver with its characteristic findings on conventional ultrasound, contrast-enhanced ultrasound with quantitative analysis and correlated with magnetic resonance imaging.Case presentation: A 15-year-old female with right upper quadrant abdominal pain was referred for liver ultrasound. A focal liver lesion was detected on B-mode ultrasound examination, and colour Doppler demonstrated no specific features. Contrast-enhanced ultrasound examination demonstrated early arterial enhancement, with a characteristic spoke-wheel pattern, centrifugal uniform filling of the lesion on the late arterial phase and sustained enhancement on the portal venous phase. Quantitative contrast-enhanced ultrasound has been performed, showing a typical curve of enhancement, as well as characteristic parametric images, supporting the interpretation of contrast-enhanced ultrasound and assisting the diagnosis. Magnetic resonance imaging demonstrated a central T2 hyperintense scar and similar enhancement characteristics as contrast-enhanced ultrasound on T1 gadolinium-enhanced sequences.

Conclusion

Contrast-enhanced ultrasound is a useful technique for the differentiation of benign from malignant liver lesions and has the potential to establish the diagnosis of focal nodular hyperplasia, based on the enhancement pattern, which is similar to that observed on magnetic resonance imaging but can be better appreciated with superior temporal, contrast and spatial resolution of contrast-enhanced ultrasound.

Paratesticular lesions: Aetiology and appearances on ultrasound

BACKGROUND

Ultrasound (US) is the primary modality for the investigation of scrotal pathology, including both intra- and paratesticular abnormalities.

OBJECTIVE

To describe the abnormalities of the paratesticular space.

MATERIALS/METHODS

The paratesticular space contains the epididymis, spermatic cord and the tunica vaginalis cavity and is affected by a variety of inflammatory or tumoral entities. Differential diagnosis based on US criteria is frequently problematic, as the findings are non-specific.

RESULTS

Some general rules apply: (i) unlike testicular lesions, extra-testicular entities are usually benign in the adult, (ii) the first steps to accurate diagnosis include careful localization of the lesion and assessment of its consistency (solid or cystic) and (iii) magnetic resonance imaging can be useful for further tissue characterization of lesions suspected to contain fat, but surgical biopsy will often provide the definite diagnosis. Contrast-enhanced ultrasound (CEUS) has been applied with limited experience indicating a narrow role, primarily for the differential diagnosis of echogenic cystic entities and the delineation of a necrotic abscess from a solid neoplasm.

DISCUSSION

The various abnormalities are discussed and illustrated.

CONCLUSION

This manuscript summarizes the literature on paratesticular lesions and the value of US in diagnosis.

EFSUMB 2020 Proposal for a Contrast-Enhanced Ultrasound-Adapted Bosniak Cyst Categorization - Position Statement

The well-established Bosniak renal cyst classification is based on contrast-enhanced computed tomography determining the malignant potential of cystic renal lesions. Ultrasound has not been incorporated into this pathway. However, the development of ultrasound contrast agents coupled with the superior resolution of ultrasound makes it possible to redefine the imaging of cystic renal lesions. In this position statement, an EFSUMB Expert Task Force reviews, analyzes, and describes the accumulated knowledge and limitations and presents the current position on the use of ultrasound contrast agents in the evaluation of cystic renal lesions.

Nonscrotal Causes of Acute Scrotum

Acute scrotum is characterized by intense acute scrotal pain, which may be associated with other symptoms and signs such as abdominal pain, inflammation, and fever. Many pathologic conditions can present in this way, most which involve the scrotal contents. Nonscrotal conditions, however, can rarely present clinically only as acute scrotum: among them, renal colic, aneurysm rupture or other causes of retroperitoneal hemorrhage, primary abdominal or pelvic tumors and metastases, pancreatitis, pelvic inflammation, and muscle injuries. The pathophysiologic characteristics of the clinical presentation, clues for diagnosis, and imaging features of a series of nonscrotal lesions presenting clinically with acute scrotal pain are herein reported and illustrated. In patients presenting with acute scrotal symptoms and normal scrotal ultrasound findings, nonscrotal causes of acute scrotal pain should be considered in the differential diagnosis. Therefore, an ultrasound investigation of the abdomen, groin, and thighs is indicated.

A pictorial review of the utility of CEUS in thoracic biopsies

Lung cancer is one of the commonest malignancies worldwide and necessitates both early and personalised treatment. A key requirement is histological sampling with immunohistochemistry obtained usually from percutaneous biopsy. Conventionally thoracic biopsies are performed using CT guidance, but more recently, there has been development of physician led ultrasound biopsy for pleural lesions. Contrast-enhanced ultrasound (CEUS) has been increasingly used in interventional procedures and is able to offer benefits for thoracic biopsies including improving lesional visualisation and characterisation, targeting viable tissue and avoiding critical vascular structures as well as evaluating for the presence of post-procedural complications. This educational review aims to benefits of the role of CEUS in thoracic biopsies.

Escalation and de-escalation of the radiology response to COVID-19 in a tertiary hospital in South London: The King's College Hospital experience

The pandemic of COVID-19 presented an enormous challenge to the medical world in terms of diagnosis, treatment and health-care management as well as service organisation and provision. This novel virus and its spread affected every aspect of modern medical practice, ranging from investigating transmission of this new pathogen, antigen testing of symptomatic patients, imaging, assessing different treatment regimens and the production of a new vaccine. Imaging played a crucial role in the diagnosis of COVID-19-related lung disease, with plain radiography and CT being the main diagnostic modalities, with ultrasound a useful bedside imaging tool. The accurate and early diagnosis of the disease was not the only issue faced by Radiology Departments across the world; prevention of nosocomial infection, creating capacity with elective imaging suspension, management and protection of the workforce being few of the numerous challenges. The purpose of this manuscript is to present the steps that the Radiology Department of a large urban tertiary facility with a local vulnerable population, undertook to adapt the imaging service and structure, both initially escalating and then de-escalating a response to the COVID-19 pandemic. A step-by-step management strategy, effective and sustained staff deployment, imaging management are presented and discussed, to provide a guide for managing a major incident in a radiology department.

Vascularity of Intra-testicular Lesions: Inter-observer Variation in the Assessment of Non-neoplastic Versus Neoplastic Abnormalities After Vascular Enhancement With Contrast-Enhanced Ultrasound

The aim of this study is to assess the additional benefit of contrast-enhanced ultrasound (CEUS) over conventional ultrasonography (US) in identifying intra-testicular abnormalities among observers of different experiences. In this study, 91 focal testicular lesions (46 neoplastic, 45 non-neoplastic) imaged with gray-scale US/Doppler US and CEUS were classified using a 5-point scale. Three experienced and four inexperienced observers rated each lesion using gray-scale/color Doppler US alone and then with the addition of CEUS. Improved diagnostic specificity and accuracy with the addition of CEUS was observed for both experienced (specificity: 71.1% vs. 59.3%, p = 0.005; accuracy: 83.5% vs. 76.9%, p = 0.003) and inexperienced observers (specificity: 75.6% vs. 51.7%, p = 0.005; accuracy: 80.2% vs. 72.0%, p < 0.001). Significant inter-observer variability between the experienced and inexperienced observers when assessing conventional US alone was eliminated with the addition of CEUS. CEUS improves diagnostic accuracy of focal intra-testicular lesions for both experienced and inexperienced observers and reduces inter-observer variability in inexperienced operators.

Ultrasound-based liver elastography: current results and future perspectives

Chronic liver disease affects 185 million population worldwide. It encompasses a heterogenous disease spectrum, but all can lead to the development of liver fibrosis. The degree of liver fibrosis is not only a prognosticator, but has also been used to guide the treatment strategy and to evaluate treatment response. Traditionally, staging of liver fibrosis is determined on histological analysis using samples obtained from an invasive liver biopsy. Ultrasound-based liver elastography is a non-invasive method of assessing diffuse liver disease in patients with known chronic liver disease. The use of liver elastography has led to a significant reduction in the number of liver biopsies performed to assess the severity of liver fibrosis and a liver biopsy is now reserved for only select sub-groups of patients. The aim of this review article is to discuss the key findings and current evidence for ultrasound-based elastography in diffuse liver disease as well as the technical challenges and to evaluate the potential research direction.

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.

Extent of pulmonary thromboembolic disease in patients with COVID-19 on CT: relationship with pulmonary parenchymal disease

AIM

To report the severity and extent of pulmonary thromboembolic disease (PTD) in COVID-19 patients undergoing computed tomography pulmonary angiography (CTPA) in a tertiary centre.

MATERIALS AND METHODS

This is a retrospective analysis of COVID-19 patients undergoing CTPA over a period of 27 days. The presence, extent, and severity of PTD were documented. Two observers scored the pattern and extent of lung parenchymal disease including potential fibrotic features, as well as lymph node enlargement and pleural effusions. Consensus was achieved via a third observer. Interobserver agreement was assessed using kappa statistics. Student's t-test, chi-squared, and Mann-Whitney U-tests were used to compare imaging features between PTD and non-PTD sub-groups.

RESULTS

During the study period, 100 patients with confirmed COVID-19 underwent CTPA imaging. Ninety-three studies were analysed, excluding indeterminate CTPA examinations. Overall incidence of PTD was 41/93 (44%) with 28/93 patients showing small vessel PTD (30%). D-dimer was elevated in 90/93 (96.8%) cases. A high Wells' score did not differentiate between PTD and non-PTD groups (p=0.801). The interobserver agreement was fair (kappa=0.659) for parenchymal patterns and excellent (kappa=0.816) for severity. Thirty-four of the 93 cases (36.6%) had lymph node enlargement; 29/34 (85.3%) showed no additional source of infection. Sixteen of the 93 (17.2%) cases had potential fibrotic features.

CONCLUSION

There is a high incidence of PTD in COVID-19 patients undergoing CTPA and lack of a risk stratification tool. The present data indicates a higher suspicion of PTD is needed in severe COVID-19 patients. The concomitant presence of possible fibrotic features on CT indicates the need for follow-up.

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: Development of Syllabus for Core Theoretical and Practical Competencies

Contrast-enhanced ultrasound (CEUS) is dependent on the observer's competencies, and thus, appropriate education and testing of individual competency is essential. The current international curriculum in CEUS is methodologically weak and lacks validated competency assessment tests. In this study, we aimed to develop a syllabus for core competencies in CEUS using the Delphi process and an international panel of experts. A core writing group constructed an initial draft of the syllabus based on the existing literature. Eight international experts in CEUS or medical education were recruited as Delphi panelists. The draft underwent iterative and anonymous Delphi rounds until a pre-defined level of consensus was reached. The final syllabus consisted of 16 items, which were indexed in two main domains and in procedural order. An expert-generated proposal for a syllabus of core CEUS competencies has been constructed via the Delphi process and may serve as framework for future development of a CEUS curriculum, including competency assessment tests.

Contrast imaging ultrasound for the detection and characterization of carotid vulnerable plaque

Not only the degree of luminal narrowing but also the plaque morphology and composition play an important role in risk stratification of carotid atherosclerotic lesions. During the last few years, carotid contrast-enhanced ultrasound (CEUS) has emerged as a valuable imaging tool to assess such vulnerable carotid plaques. This review article discussed the use of CEUS for the detection of carotid plaque irregularities and ulcerations as well as the quantification of intraplaque neovascularization and its correlation with histology and inflammatory biomarkers. Apart from evaluating for markers of vulnerable carotid plaques, CEUS enhancement is directly associated with past cerebrovascular events. More importantly, preliminary evidence has shown that CEUS could be used to predict future cerebrovascular and cardiovascular events. Despite the progress in CEUS imaging for carotid atherosclerotic disease, past studies still suffer from the retrospective nature, small sample size, and a lack of matched, well controlled prospective studies. In the future, large multi-center prospective studies addressing the relationship between CEUS findings and patient clinical outcomes in carotid atherosclerotic disease are warranted.

Correction to: Contrast-enhanced ultrasound (CEUS) of the lung reveals multiple areas of microthrombi in a COVID-19 patient

The original version of this article unfortunately contained two mistakes.

The role of multiparametric ultrasound in the diagnosis of paediatric scrotal pathology

Multiparametric ultrasound (MPUS), combining conventional techniques (greyscale and colour Doppler ultrasound), ultrasound strain elastography, and contrast-enhanced ultrasound (CEUS), has been successfully used in the assessment of adult scrotal pathology. Contrast-enhanced ultrasound can confidently establish testicular tissue vascularity even in the small-volume paediatric testis. Elastography provides further assessment of tissue stiffness, potentially adding useful diagnostic information. In children, ultrasonography is particularly advantageous, being safe, radiation-free and negating the need for sedation or general anaesthesia during the imaging evaluation. In this review article, we aim to familiarise readers with the MPUS scanning protocol used for paediatric scrotal examination and provide an overview of scrotal MPUS features, with particular focus to clinical indications where MPUS may be advantageous over conventional ultrasonography.

The role of contrast-enhanced ultrasound (CEUS) in the evaluation of scrotal trauma: a review

Testicular trauma is common, usually trivial and rarely requires hospital attendance, but if it does, then imaging becomes essential as scrotal assessment may be difficult due to pain and/or scrotal disruption. Ultrasound (US) assumes a crucial role as other cross-sectional modalities have a limited use in the acute presentation. Despite the acceptable accuracy of conventional US techniques, there are limitations which hinder a thorough evaluation, critically the assessment of tissue viability, crucial for clinical management and prognosis. Contrast-enhanced ultrasound (CEUS) has been shown to offer improved flow visualisation and tissue perfusion compared with conventional Doppler techniques. CEUS can accurately and confidently demonstrate the viability of testicular parenchyma, delineate fracture lines and haematomas and guide treatment for testis-sparing surgery or orchidectomy. The purpose of this review is to present the literature, familiarise physicians with the principles of CEUS and findings of scrotal trauma and illustrate the main abnormalities through characteristic and educative cases.

Ultrasound-based liver elastography in the assessment of fibrosis

Ultrasound-based elastography has rapidly replaced the need for liver biopsy in most patients with chronic liver disease in recent years. The technique is now widely supported by many manufacturers. This review will introduce various current ultrasound-based elastography techniques, review the physics and scanning techniques, discuss potential cofounding factors as well as summarising the evidence for its use in staging liver fibrosis using shear-wave elastography among different disease aetiologies. Future challenges and directions will be also be discussed.