Diagnostic performance of ultrasound vs. ultrasound-guided FNAc in thyroid nodules: data from the ElaTION trial.

INTRODUCTION: ElaTION is a large multi-centre pragmatic randomised controlled trial, performed in 18 secondary/tertiary hospitals across England, comparing elastography ultrasound-guided fine needle aspiration cytology (EUS-FNAC) with ultrasound-guided FNAC (US-FNAC) alone in the diagnostic assessment of thyroid nodules. Secondary trial outcomes, reported here, assessed the accuracy of ultrasound-alone (US) compared with US-guided FNAC to inform and update current practice guidelines. METHODS: Adults with single or multiple thyroid nodules who had not undergone previous FNAC were eligible. Radiologists assessed all thyroid nodules using US alone, thereby enabling assessment of its accuracy (sensitivity and specificity) versus US-FNAC. RESULTS: Of the 982 participants, a final definitive diagnosis was obtained in 688, who were included in the final analyses. The sensitivity of US-alone was the same as US-FNAC (0.91, [95% CI 0.85, 0.97] vs 0.87 [95%CI 0.80-0.95], p=0.37). US alone had statistically significant lower specificity than US-FNAC alone (0.48 vs 0.67 respectively, p<0.0001). The malignancy rate on histology in a nodule classified as benign on ultrasound (U2) was 9/263 (3.42%) and on cytology (Thy2) was 15/353 (4.25%), whereas the malignancy rate in a nodule that was benign on both (U2, Thy2) was 3/210 (1.43%). Malignancy risk for U3, U4, and U5 nodules was 68/304 (22.4%), 43/83 (51.8%), and 29/38 (76.3%) respectively (p<0.0001). Yet 80/982 (8%) patients were discharged despite having U3-U5 scans with Thy1 (non-diagnostic) FNAC and no definitive diagnosis.Malignancy risk was higher in smaller nodules: <10mm 23/60 (38.3%), 10-20mm 46/162 (28.4 %), and >20mm 80/466 (17.2%) (p<0.0001). Nodules with indeterminate cytology with atypical features (Thy3a) carried a similar malignancy risk to those with indeterminate cytology (Thy3/3f): 27/95 (28.4%) versus 42/113 (37.2%) respectively (p=0.18). CONCLUSION: Ultrasound alone appears to be an effective diagnostic modality in thyroid nodules, confirming the recommendations of recent guidelines and the BTA classification. However, findings also suggest caution regarding existing recommendations for conservative management of non-diagnostic (Thy1/Bethesda I) and atypical (Thy3a/Bethesda III) nodules. In those cases, ultrasound (U3-5) features may help identify high-risk subgroups for more proactive management.

Real-time ultrasound elastography in the diagnosis of newly identified thyroid nodules in adults: the ElaTION RCT.

Background: Strain and shear wave elastography which is commonly used with concurrent real-time imaging known as real-time ultrasound shear/strain wave elastography is a new diagnostic technique that has been reported to be useful in the diagnosis of nodules in several organs. There is conflicting evidence regarding its benefit over ultrasound-guided fine-needle aspiration cytology alone in thyroid nodules. Objectives: To determine if ultrasound strain and shear wave elastography in conjunction with fine-needle aspiration cytology will reduce the number of patients who have a non-diagnostic first fine-needle aspiration cytology results as compared to conventional ultrasound-only guided fine-needle aspiration cytology. Design: A pragmatic, unblinded, multicentre randomised controlled trial. Setting: Eighteen centres with a radiology department across England. Participants: Adults who had not undergone previous fine-needle aspiration cytology with single or multiple nodules undergoing investigation. Interventions: Ultrasound shear/strain wave elastography-ultrasound guided fine-needle aspiration cytology (intervention arm) - strain or shear wave elastography-guided fine-needle aspiration cytology. Ultrasound-only guided fine-needle aspiration cytology (control arm) - routine ultrasound-only guided fine-needle aspiration cytology (the current standard recommended by the British Thyroid Association guidelines). Main outcome measure: The proportion of patients who have a non-diagnostic cytology (Thy 1) result following the first fine-needle aspiration cytology. Randomisation: Patients were randomised at a 1 : 1 ratio to the interventional or control arms. Results: A total of 982 participants (80% female) were randomised: 493 were randomised to ultrasound shear/strain wave elastography-ultrasound guided fine-needle aspiration cytology and 489 were randomised to ultrasound-only guided fine-needle aspiration cytology. There was no evidence of a difference between ultrasound shear/strain wave elastography and ultrasound in non-diagnostic cytology (Thy 1) rate following the first fine-needle aspiration cytology (19% vs. 16% respectively; risk difference: 0.030; 95% confidence interval -0.007 to 0.066; p = 0.11), the number of fine-needle aspiration cytologies needed (odds ratio: 1.10; 95% confidence interval 0.82 to 1.49; p = 0.53) or in the time to reach a definitive diagnosis (hazard ratio: 0.94; 95% confidence interval 0.81 to 1.10; p = 0.45). There was a small, non-significant reduction in the number of thyroid operations undertaken when ultrasound shear/strain wave elastography was used (37% vs. 40% respectively; risk difference: -0.02; 95% confidence interval -0.06 to 0.009; p = 0.15), but no difference in the number of operations yielding benign histology - 23% versus 24% respectively, p = 0.70 (i.e. no increase in identification of malignant cases) - or in the number of serious adverse events (2% vs. 1%). There was no difference in anxiety and depression, pain or quality of life between the two arms. Limitations: The study was not powered to detect differences in malignancy. Conclusions: Ultrasound shear/strain wave elastography does not appear to have additional benefit over ultrasound-guided fine-needle aspiration cytology in the diagnosis of thyroid nodules. Future work: The findings of the ElaTION trial suggest that further research into the use of shear wave elastography in the diagnostic setting of thyroid nodules is unlikely to be warranted unless there are improvements in the technology. The diagnostic difficulty in distinguishing between benign and malignant lesions still persists. Future studies might examine the role of genomic testing on fine-needle aspiration samples. There is growing use of targeted panels of molecular markers, particularly aimed at improving the diagnostic accuracy of indeterminate (i.e. Thy3) cytology results. The application of these tests is not uniform, and their cost effectiveness has not been assessed in large-scale trials. Study registration: This study is registered as ISRCTN (ISRCTN18261857). Funding: This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: 12/19/04) and is published in full in Health Technology Assessment; Vol. 28, No. 46. See the NIHR Funding and Awards website for further award information.

About half the population will have lumps in their thyroid if examined by an ultrasound scan but may not know they have one. About one in twenty people will feel a thyroid lump in their neck at some time in their life, with about one in twenty of those being malignant. Currently, the recommended way of getting a diagnosis of thyroid nodules is by using ultrasound to guide a needle to get cells from the lump, called ultrasound-guided fine-needle aspiration cytology. These cells are examined to determine the cause of the lump. If there are enough cells, Doctors can then make a diagnosis of whether the lump is benign or malignant. If not, patients will undergo another ultrasound-guided fine-needle aspiration cytology. One in five ultrasound-guided fine-needle aspiration cytologies are non-diagnostic with an overall false-positive rate of approximately 24%. This means one in five patients, with benign disease, may undergo unnecessary diagnostic operations. Thyroid surgery carries risks of complications, which could be avoided if we had better ways to diagnose which patients actually need an operation. We conducted a randomised trial, ElaTION, to determine if a new technology called strain and shear wave elastography, commonly known as real-time elastography, would be better at helping the radiologist take a sufficient sample of cells and reduce the number of non-diagnostic results, reducing the number of fine-needle aspiration cytologies required to make a definitive diagnosis. Nine hundred eighty-two patients were recruited between 2015 and 2018 and followed up until the end of the trial. Patients were randomised into two groups: 489 patients received the standard ultrasound-guided fine-needle aspiration cytology alone, and 493 patients received ultrasound-guided fine-needle aspiration cytology + shear wave elastography. Ultrasound shear/strain wave elastography did not reduce non-diagnostic cytology at first fine-needle aspiration cytology or improve the likelihood of determining whether the lump is benign or malignant. The results of ElaTION do not support the use of shear wave elastography-fine-needle aspiration cytology in the diagnosis of thyroid nodules.

A review of multiparametric ultrasound imaging in the clinical setting: scrotal contents.

The innovative techniques in ultrasound have added a new dimension to investigating superficially located areas such as the contents of the scrotal sac. High frequency transducers, improved technology with the addition of elastography, contrast enhanced ultrasound and microvascular imaging has resulted in a further improvement in diagnostic capabilities. The ability to clearly demonstrate the presence or absence of vascularity within the area under investigation adds an additional dimension to operator confidence in establishing the presence of infarction, global or segmental, or the walls and cavity of an abscess in the testis or epididymis. Increased vascularity of a tumor aids the differential diagnosis based on the flow dynamics of the microbubble contrast, benign lesions likely to retain contrast. Elastography has the ability to ascertain the stiffness of tissue, and when used in conjunction with other ultrasound methods adds to the understanding of the likelihood of a malignant abnormality being present. All the different techniques come under the umbrella term 'multiparametric ultrasound', with the application in the scrotal sac detailed in this article.

Quantitative Ultrasound and Ultrasound-Based Elastography for Chronic Liver Disease: Practical Guidance, From the AJR Special Series on Quantitative Imaging.

Quantitative ultrasound (QUS) and ultrasound-based elastography techniques are emerging as non-invasive effective methods for assessing chronic liver disease. They are more accurate than B-mode imaging alone and more accessible than MRI as alternatives to liver biopsy. Early detection and monitoring of diffuse liver processes such as steatosis, inflammation, and fibrosis play an important role in guiding patient management. The most widely available and validated techniques are attenuation-based QUS techniques and shear-wave elastography techniques that measure shear-wave speed. Other techniques are supported by a growing body of evidence and are increasingly commercialized. This review explains general physical concepts of QUS and ultrasound-based elastography techniques for evaluating chronic liver disease. The first section describes QUS techniques relying on attenuation, backscatter, and speed of sound. The second section discusses ultrasound-based elastography techniques analyzing shear-wave speed, shear-wave dispersion, and shear-wave attenuation. With an emphasis on clinical implementation, each technique's diagnostic performance along with thresholds for various clinical applications are summarized, to provide guidance on analysis and reporting for radiologists. Measurement methods, advantages, and limitations are also discussed. The third section explores developments in quantitative contrast-enhanced and vascular ultrasound that are relevant to chronic liver disease evaluation.

Follow-up of non-palpable testicular incidentalomas under 1 cm: does growth rate differentiate malignant and non-malignant lesions?

OBJECTIVE: To determine whether small, incidentally detected testicular lesions can be safely followed up, by assessing growth rate and volume threshold for benign vs. malignant lesions. METHODS: This retrospective observational study includes a consecutive series of 130 testicular incidentalomas < 1 cm and with negative tumour markers identified from October 2001 to November 2022, which were initially followed up with ultrasound. A total of 39 cases proceeded to surgery during the study period, either due to lesion growth (n = 28) or patient preference/recommendation by the referring urologist (n = 11). For the lesions that were growing, specific growth rate (SGR) and doubling time (DT) were calculated assuming an exponential growth pattern. In addition, the velocity of increase of the average diameter (∆Dav) and of the maximum diameter (∆Dmax) were calculated. RESULTS: Of the 130 nodules that were initially followed up, six disappeared, eight were reduced in size, eighty-eight were stable, and twenty-eight increased in size. For operated nodules all 18 malignant tumours, 8/9 benign tumours, and 2/12 surgically proved non-neoplastic lesions were growing. The best cut-off values of the growth indicators to differentiate between malignant and non-malignant histology were 3.47 × 10-3%volume/day, ≤ 179 days, > 10 × 10-3 mm/day, and > 5 × 10-3 mm/day for SGR, DT, ∆Dmax, ∆Dav, respectively. CONCLUSIONS: Malignant and non-malignant small incidentalomas can be effectively differentiated based on growing parameters, even though overlap exists. An increase of the maximum diameter of about 1 mm and 2 mm in three months and in six months, respectively, suggests malignancy. CLINICAL RELEVANCE STATEMENT: Growing parameters allow an educated assessment of benign and malignant small testicular incidentalomas. Non-aggressive management is justified and safe when follow-up includes self-examination and tumour marker assessment to reduce the risk of interval tumour growth. KEY POINTS: Small, non-palpable and asymptomatic testicular nodules < 1 cm are unexpectedly discovered during scrotal ultrasound. Growth indicators estimate the potential malignancy, even though overlap with non-malignant lesions exists. Non-growing incidentalomas can be safely followed up.

Multiparametric Ultrasound for Focal Testicular Pathology: A Ten-Year Retrospective Review.

Conventional ultrasonography (US), including greyscale imaging and colour Doppler US (CDUS), is pivotal for diagnosing scrotal pathologies, but it has limited specificity. Historically, solid focal testicular abnormalities often led to radical orchidectomy. This retrospective study evaluated the utilisation of contrast-enhanced ultrasound (CEUS) and strain elastography (SE) in investigating intratesticular focal abnormalities. A total of 124 cases were analysed. This study underscored the superior diagnostic capabilities of CEUS in detecting vascular enhancement in all malignant cases, even those with undetectable vascularity by CDUS. It also highlighted the potential of CEUS in identifying distinctive vascular patterns in benign vascular tumours. Definitive confirmation of benignity could be obtained when the absence of enhancement was demonstrated on CEUS. While SE alone offered no distinctive advantage in differentiating between benign and malignant pathologies, we demonstrated that incorporating a combination of CEUS and SE into the evaluation of focal testicular abnormalities could improve diagnostic performance metrics over conventional CDUS. Our findings underscore the role of advanced ultrasound techniques in enhancing the evaluation of focal testicular abnormalities in clinical practice and could aid a shift towards testis-sparing management strategies.

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.

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.

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.

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.

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.

Testicular torsion: an avascular testis at color Doppler ultrasound is not enough to prove the diagnosis.

INTRODUCTION: A Doppler ultrasound (US) of the scrotum is commonly used to improve the diagnostic confidence for testicular torsion in an emergency setting. However, the sensitivity of this investigation to identify torsion varies largely. This is due, in part, to a lack of guidelines on how-to perform the US and therefore training is necessary. EVIDENCE ACQUISITION: The Scrotal and Penile Imaging Working Group of the European Society of Urogenital Radiology (ESUR-SPIWG) and the Section of Urological Imaging of the European Association of Urology (ESUI) established a joint panel of experts to standardize Doppler US investigation of patients with testicular torsion. The panel reviewed the available literature, identified accumulated knowledge and limitations, and released recommendations on how-to perform Doppler US in patients with acute scrotal pain. EVIDENCE SYNTHESIS: Diagnosis of testicular torsion is based on clinical evaluation and investigation of the cord, the testis, and the paratesticular structures. A preliminary clinical evaluation, including history and palpation, is necessary. Grey scale US, color Doppler US and spectral analysis must be performed by a sonologist with at least level 2 competence. Modern equipment with adequate grey-scale and Doppler capabilities are required. CONCLUSIONS: Standardization of Doppler US in suspicious testicular torsion is presented, with the aim to obtain comparable results among different centres, prevent unnecessary operations, and improve patient management.

Microvascular Flow Imaging: A State-of-the-Art Review of Clinical Use and Promise.

Vascular imaging with color and power Doppler is a useful tool in the assessment of various disease processes. Assessment of blood flow, from infarction and ischemia to hyperemia, in organs, neoplasms, and vessels, is used in nearly every US investigation. Recent developments in this area are sensitive to small-vessel low velocity flow without use of intravenous contrast agents, known as microvascular flow imaging (MVFI). MVFI is more sensitive in detection of small vessels than color, power, and spectral Doppler, reducing the need for follow-up contrast-enhanced US (CEUS), CT, and MRI, except when arterial and venous wash-in and washout characteristics would be helpful in diagnosis. Varying clinical applications of MVFI are reviewed in adult and pediatric populations, including its technical underpinnings. MVFI shows promise in assessment of several conditions including benign and malignant lesions in the liver and kidney, acute pathologic abnormalities in the gallbladder and testes, and superficial lymph nodes. Future potential of MVFI in different conditions (eg, endovascular repair) is discussed. Finally, clinical cases in which MVFI correlated and potentially obviated additional CEUS, CT, or MRI are shown.

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.

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.

Contrast-enhanced US of Segmental Testicular Infarction.

Online supplemental material is available for this article.