Transthoracic ultrasound (TUS) is an established imaging modality for the diagnosis and bedside monitoring of pleural effusions, pneumothorax, inflammatory pleural disease, thoracic wall lesions, peripheral pulmonary consolidations, and interstitial lung diseases. Contrast-enhanced ultrasound (CEUS) further improves lesion characterization by differentiating viable inflammatory tissue from necrosis and abscess formation. While the sonographic appearance of common thoracic diseases is well described, ultrasound findings in rare pulmonary and pleural conditions remain insufficiently documented. This review presents the characteristic transthoracic ultrasound (TUS) findings in several uncommon thoracic disorders, including abscessing fire-eater's pneumonia after paraffin aspiration, tracheal hemangioma, thoracic wall hemangioma, biliopleural fistula following percutaneous transhepatic cholangiodrainage (PTCD), bronchial rupture with hemopneumothorax, spontaneous pneumomediastinum, esophagopleural fistula, diaphragmatic cyst, and post-traumatic diaphragmatic paralysis. The sonographic findings are correlated with the clinical presentation and complementary imaging modalities.

Primary cardiac tumors are rare, accounting for less than 0.1% of all neoplasms, whereas secondary cardiac involvement is considerably more frequent, particularly in advanced oncological disease. Although imaging modalities such as echocardiography, cardiac magnetic resonance imaging, computed tomography, and positron emission tomography are routinely used for the diagnosis and characterization of cardiac masses, the role of contrast-enhanced ultrasound (CEUS) has not yet been systematically evaluated. CEUS enables real-time visualization of vascularity and perfusion and offers important advantages for distinguishing tumors from thrombi, characterizing benign and malignant lesions, and detecting embolic sequelae in distant organs. In this review, we summarize current knowledge on the epidemiology, pathology, and clinical presentation of cardiac tumors and provide an overview of imaging strategies with a particular focus on CEUS. We illustrate the application of CEUS in the assessment of benign tumors such as myxomas and papillary fibroelastomas, rare benign entities, malignant cardiac tumors including sarcomas and lymphomas, and secondary cardiac involvement due to metastatic disease. The diagnostic value of CEUS is highlighted through image and video examples, demonstrating its ability to delineate perfused versus non-perfused tissue and to differentiate tumor vascularity patterns. CEUS represents a promising and underutilized imaging technique in the evaluation of cardiac tumors. It complements established imaging modalities, provides unique pathophysiological insights, and has the potential to improve diagnostic accuracy and clinical decision-making in selected patients.

OBJECTIVE:Ultrasound fusion imaging is a hybrid technique that combines real-time ultrasonography (US) with pre-acquired computed tomography (CT) or magnetic resonance imaging (MRI), using electromagnetic (EM) tracking to enable precise spatial correlation between modalities. This technology is increasingly used for liver imaging and interventions, especially when conventional B-mode US fails to provide adequate lesion visualization. The aim of this technical review and position statement is to evaluate the technical accuracy (target registration errors) and lesion visibility of ultrasound fusion imaging based on published evidence and expert consensus. METHODS:This manuscript was designed as the technical component of a two-part World Federation for Ultrasound in Medicine and Biology (WFUMB) position statement. A systematic review was conducted using a PICO framework focused on two core questions: (i) to evaluate EM-tracked fusion target registration errors (PICO T1), and (ii) whether fusion improves visibility of lesions in difficult-to-image liver lesions (PICO T2). Literature from January 2012 to January 2025 was searched across PubMed, Scopus, Embase, and IEEE Xplore, with manual citation tracking and AI-assisted query generation. Eligible studies included research on US/CEUS fusion with CT/MRI, reporting technical accuracy and lesion conspicuity. RESULTS:The technical accuracy of fusion imaging was consistently high, with target registration errors (TRE) of ∼1-3 mm in ideal phantom settings and ∼4-14 mm in clinical studies. Automatic registration methods were faster and similarly accurate as manual registration, possibly reducing operator dependence. Fusion imaging improved the detectability of lesions not visible (occult) on conventional B-mode US, increasing the diagnostic yield and enabling successful interventions (e.g., ablation) in up to 90%-95% of cases. Safety profiles across studies were favorable, with major complication rates generally below 2%. Furthermore, fusion imaging might prove especially beneficial for treating tumors in difficult locations (e.g., caudate lobe, peribiliary lesions). CONCLUSION:Ultrasound fusion imaging significantly enhances the spatial accuracy of liver interventions by aligning real-time US with CT/MRI datasets. It improves interventional procedures guidance and maintains a low complication profile as compared to conventional US alone. Advancements in artificial intelligence (AI) and augmented reality (AR) are expected to further optimize image co-registration workflows and clinical outcomes. This technical review supports the broader adoption of fusion imaging as a key tool in liver imaging and intervention.

Aim:To evaluate the benefit of abdominal ultrasonography performed routinely and thus independently of symptomatology in patients in the intensive care unit, and to assess the value of a portable ultrasound device. Diagnostic yield and documented results with clinical consequences were considered and compared with findings obtained using a high-end ultrasound device. Material and methods:A total of 120 patients of an internal medicine intensive care unit were included over 12 months. The investigator had limited experience in sonography (approximately 300 abdominal sonographies performed). The abdomen and basal portions of the thorax were examined. Results:The most common pathological findings were renal cysts in 34/120 (28.3%), left-sided or right-sided pleural effusions in 33/120 (27.5%) and 29/120 (24.2%) patients, respectively, dilatation of the vena cava in 24/120 (20.0%), and urinary retention in 14/120 (11.7%) patients. In 13/120 (10.8%) patients, the sonographic examination resulted in a diagnostic consequence, while in 38/120 (31.7%) patients in a therapeutic consequence. Among the false-negative findings using the hand-held ultrasound device, no finding was of therapeutic relevance. Four findings that were missed by the hand-held ultrasound device were diagnostically significant: two lesions of the kidney, one lesion of the liver, and one case of urinary stasis kidney. Conclusions:With the hand-held ultrasound device, only 33 of 52 focal lesions were detected. Thus, a high-end ultrasound device cannot be replaced by a hand-held ultrasound device for this purpose, but certain clinical questions can be answered reliably with a hand-held ultrasound device (such as the presence of a puncture-worthy pleural effusion in patients with dyspnea, or verification of the volume status based on the diameter of the vena cava).

EUS has become an essential tool in pediatric gastroenterology for high-resolution imaging of the gastrointestinal tract and surrounding organs. This review describes the clinical applications and outcomes of EUS in diagnosing and managing pediatric gastrointestinal, pancreatic, biliary, and intestinal diseases. EUS is particularly useful in abdominal diseases, offering an accurate and high-resolution imaging method without radiation exposure. Despite its proven efficacy in children, EUS remains underutilized due to technical challenges and limited pediatric-specific expertise. Thus, the study highlights the importance of increasing the availability and training for pediatric EUS to enhance diagnostic precision and therapeutic options in children.

In this 14th document in a series of papers entitled “Controversies in Endoscopic Ultrasound” we discuss various aspects of EUS-guided biliary drainage that are debated in the literature and in practice. Endoscopic retrograde cholangiography is still the reference technique for therapeutic biliary access, but EUS-guided techniques for biliary access and drainage have developed into safe and highly effective alternative options. However, EUS-guided biliary drainage techniques are technically demanding procedures for which few training models are currently available. Different access routes require modifications to the basic technique and specific instruments. In experienced hands, percutaneous transhepatic cholangiodrainage is also a good alternative. Therefore, in this paper, we compare arguments for different options of biliary drainage and different technical modifications.

It is time for a change. CEUS is an established method that should be much more actively included in renal cyst monitoring strategies. This review compares the accuracies, strengths, and weaknesses of CEUS, CECT, and MRI in the classification of renal cysts. In order to avoid overstaging by CEUS, a further differentiation of classes IIF, III, and IV is required. A further development in the refinement of the CEUS-Bosniak classification aims to integrate CEUS more closely into the monitoring of renal cysts and to develop new and complex monitoring algorithms.

In this series of papers on comments and illustrations of the World Federation for Medicine and Biology (WFUMB) guidelines on contrast enhanced ultrasound (CEUS) the topics of non-infectious and non-neoplastic focal liver lesions (FLL) are discussed. Improved detection and characterization of common FLL are the main topics of these guidelines but detailed and illustrating information is missing. The focus in this paper is on non-infectious and non-neoplastic FLL and their appearance on B-mode, Doppler ultrasound and CEUS features. Knowledge of these data should help to raise awareness of these rarer findings, to think of these clinical pictures in the corresponding clinical situation, to interpret the ultrasound images correctly and thus to initiate the appropriate diagnostic and therapeutic steps in time.

ZusammenfassungDie Ultraschalldiagnostik ist in vielen klinischen Situationen das Verfahren der ersten Wahl für die abdominelle Bildgebung. Neben dem Graustufenbild (B-Modus) und den klassischen Dopplerverfahren ermöglichen die kontrastmittelverstärkte Sonografie (CEUS), die Elastografie und die Fettquantifizierung eine multimodale Charakterisierung von Organen und Gewebestrukturen. Panorama- und 3D-Verfahren sowie Bildfusion haben die Befunddarstellung erweitert. Die Entwicklung tragbarer Kleingeräte führt zu einer Erweiterung der Einsatzmöglichkeiten der konventionellen Ultraschalldiagnostik.In dieser Übersichtsarbeit werden moderne sonografisch relevante Verfahren diskutiert sowie Geräteklassen und Stufenkonzepte beschrieben und anhand der wissenschaftlichen Evidenz bewertet. Ferner werden Hinweise zu Qualitätsstandards für die abdominelle Ultraschalldiagnostik vermittelt.

In this series of papers on comments and illustrations of the World Federation for Medicine and Biology (WFUMB) guidelines on contrast enhanced ultrasound (CEUS) the topics of bacterial infections are discussed. Improved detection and characterization of common focal liver lesions (FLL) are the main topics of these guidelines but detailed and illustrating information is missing. The focus in this paper on infectious (bacterial) focal liver lesions is on their appearance on B-mode and Doppler ultrasound and CEUS features. Knowledge of these data should help to raise awareness of these rarer findings, to think of these clinical pictures in the corresponding clinical situation, to interpret the ultrasound images correctly and thus to initiate the appropriate diagnostic and therapeutic steps in time.

A definite pathologic diagnosis of intrapancreatic metastasis is crucial for the management decision, i.e., curative or palliative surgery versus chemotherapy or conservative/palliative therapy. This review focuses on the appearance of intrapancreatic metastases on native and contrast-enhanced transabdominal ultrasound and endoscopic ultrasound. Differences and similarities in relation to the primary tumor, and the differential diagnosis from pancreatic carcinoma and neuroendocrine neoplasms are described. The frequency of intrapancreatic metastases in autopsy studies and surgical resection studies will be discussed. Further emphasis is placed on endoscopic ultrasound-guided sampling to confirm the diagnosis.

Intraductal papillary neoplasm of the bile ducts is a rare tumor. Characteristic features include bile duct dilatation, cystic lesions with communication to the bile ducts, and intraluminal solid nodules arising from the bile duct wall. As in pancreatic intraductal papillary mucinous neoplasia, intestinal, pancreaticobiliary, gastric, and oncocytic types are described. Intraductal papillary neoplasm of the bile ducts has a high potential for malignancy, and patients should be surgically resected when possible. In this review, the complex imaging diagnosis is presented. The main focus is on contrast-enhanced ultrasound, an established method for many other indications whose potential on the biliary system should be better exploited. In the present article, typical contrast-enhanced ultrasound findings in intraductal papillary neoplasm of the bile ducts are demonstrated.

Abstract EUS–guided interventions have become widely accepted therapeutic management options for drainage of peripancreatic fluid collections. Apart from endosonographic skills, EUS interventions require knowledge of the endoscopic stenting techniques and familiarity with the available stents and deployment systems. Although generally safe and effective, technical failure of correct stent positioning or serious adverse events can occur, even in experts' hands. In this article, we address common and rare adverse events in transmural EUS-guided stenting, ways to prevent them, and management options when they occur. Knowing the risks of what can go wrong combined with clinical expertise, high levels of technical skills, and adequate training allows for the safe performance of EUS-guided drainage procedures. Discussing the procedural risks and their likelihood with the patient is a fundamental part of the consenting process.

During the aging process, typical morphological changes occur in the pancreas, which leads to a specific "patchy lobular fibrosis in the elderly." The aging process in the pancreas is associated with changes in volume, dimensions, contour, and increasing intrapancreatic fat deposition. Typical changes are seen in ultrasonography, computed tomography, endosonography, and magnetic resonance imaging. Typical age-related changes must be distinguished from lifestyle-related changes. Obesity, high body mass index, and metabolic syndrome also lead to fatty infiltration of the pancreas. In the present article, age-related changes in morphology and imaging are discussed. Particular attention is given to the sonographic verification of fatty infiltration of the pancreas. Ultrasonography is a widely used screening examination method. It is important to acknowledge the features of the normal aging processes and not to interpret them as pathological findings. Reference is made to the uneven fatty infiltration of the pancreas. The differential diagnostic and the differentiation from other processes and diseases leading to fatty infiltration of the pancreas are discussed.

Endobronchial ultrasound (EBUS) is a minimally invasive highly accurate and safe endoscopic technique for the evaluation of mediastinal lymphadenopathy and mediastinal masses including centrally located lung tumors. The combination of transbronchial and transoesophageal tissue sampling has improved lung cancer staging, reducing the need for more invasive and surgical diagnostic procedures. Despite the high level of evidence regarding EBUS use in the aforementioned situations, there are still challenges and controversial issues such as follows: Should informed consent for EBUS and flexible bronchoscopy be different? Is EBUS able to replace standard bronchoscopy in patients with suspected lung cancer? Which is the best position, screen orientation, route of intubation, and sedation/anesthesia to perform EBUS? Is it advisable to use a balloon in all procedures? How should the operator acquire skills and how should competence be ensured? This Pro-Con article aims to address these open questions.

As part of the aging process, fibrotic changes, fatty infiltration, and parenchymal atrophy develop in the pancreas. The pancreatic duct also becomes wider with age. This article provides an overview of the diameter of the pancreatic duct in different age groups and different examination methods. Knowledge of these data is useful to avoid misinterpretations regarding the differential diagnosis of chronic pancreatitis, obstructive tumors, and intraductal papillary mucinous neoplasia (IPMN).

Abdominal ultrasound is the method of first choice in many clinical situations. Gray scale imaging (B-mode) and conventional Doppler techniques are nowadays complemented by contrast-enhanced ultrasound (CEUS), elastography, fat quantification and further technologies which allow multimodal characterization of organs and tissue structure using panoramic imaging, 3D-techniques and image fusion. The development of small portable devices augments the spectrum for sonographic diagnostics. In this review, we describe the current status of ultrasound technology based on published evidence. In addition, we provide guidance for quality assurance.

Aim: To investigate the diagnostic value of resistance index (RI) in differentiating focal liver lesions. Patients and methods: In this retrospective study, a total of 576 patients with histologically confirmed focal liver lesions were included. Each patient underwent B-mode ultrasound examination and color Doppler ultrasound examination. The RI values of different focal liver lesions were recorded and compared. Results: The mean RI value of benign lesions was significantly lower than that of malignant lesions (0.54 +/- 0.10 vs. 0.71 +/- 0.12) (p <0.05). In malignant lesions, the RI value of intrahepatic cholangiocarcinoma was significantly lower than that of hepatocellular carcinoma lesions. Furthermore, in hepatocellular carcinoma lesions, the RI of large lesions (group 4: >10 cm) was significantly lower than that of small lesions (group 1: <= 2 cm, group 2: 2-5 cm) (p <0.05). Taken RI of 0.615 as a cutoff value to differentiate malignant and benign lesions, the sensitivity, specificity, positive predictive value and negative predictive value were 82.80%, 81.00%, 81.34% and 82.48%, respectively. Conclusion: Color Doppler ultrasound examination is a valuable imaging method in detecting blood flow signal within liver lesions. The RI parameter should be helpful in differentiating malignant and benign liver tumors.

EUS-guided biliary drainage (EUS-BD) has recently gained widespread acceptance as a minimally invasive alternative method for biliary drainage. Even in experienced endoscopy centers, ERCP may fail due to inaccessibility of the papillary region, altered anatomy (particularly postsurgical alterations), papillary obstruction, or neoplastic gastric outlet obstruction. Biliary cannulation fails at first attempt in 5%-10% of cases even in the absence of these factors. In such cases, alternative options for biliary drainage must be provided since biliary obstruction is responsible for poor quality of life and even reduced survival, particularly due to septic cholangitis. The standard of care in many centers remains percutaneous transhepatic biliary drainage (PTBD). However, despite the high technical success rate with experienced operators, the percutaneous approach is more invasive and associated with poor quality of life. PTBD may result in long-term external catheters for biliary drainage and carry the risk of serious adverse events (SAEs) in up to 10% of patients, including bile leaks, hemorrhage, and sepsis. PTBD following a failed ERCP also requires scheduling a second procedure, resulting in prolonged hospital stay and additional costs. EUS-BD may overcome many of these limitations and offer some distinct advantages in accessing the biliary tree. Current data suggest that EUS-BD is safe and effective when performed by experts, although SAEs have been also reported. Despite the high number of clinical reports and case series, high-quality comparative studies are still lacking. The purpose of this article is to report on the current status of this procedure and to discuss the tools and techniques for EUS-BD in different clinical scenarios.