Peripheral Pulmonary Lesions in Confirmed Pulmonary Arterial Embolism: Follow-up Study of B-Mode Ultrasound and of Perfusion Patterns Using Contrast-Enhanced Ultrasound (CEUS).

PURPOSE: This retrospective study aimed to describe the B-mode lung ultrasound (B-LUS) and contrast-enhanced ultrasound (CEUS) follow-up patterns of peripheral pulmonary lesions (PPLs) in patients with confirmed pulmonary embolism (PE). PATIENTS AND METHODS: Data from 27 patients with a confirmed diagnosis of PE and PPLs over 5 mm from October 2009 to November 2018 were included retrospectively in the study. The inclusion criteria were performance of a baseline CEUS examination, a short-term B-LUS and CEUS follow-up, and a long-term B-LUS follow-up of PPLs. The homogeneity of enhancement of PPLs (homogeneous/inhomogeneous/absent) on CEUS and the presence and size of PPLs on B-LUS were evaluated. RESULTS: A total of n = 25/27 (92.6%) lesions showed absent or inhomogeneous enhancement during baseline examination or short-term follow-up, indicating impaired perfusion. On short-term CEUS follow-up, 9/27 cases (33.3%) showed a pattern shift. On B-LUS long-term follow-up, 26/27 lesions (96.3%) were detectable for an average of 10 weeks (range 3-32 weeks). The size of reference lesions was significantly reduced at the time of the final follow-up examination (P < .05). CONCLUSION: B-LUS follow-up showed that, in patients with confirmed PE, PPLs had a delayed regression. On CEUS follow-up examination, various perfusion patterns of PPLs were observed, indicating the different ages and the variable reparative processes of pulmonary infarction. In PPLs independent of the underlying signs and symptoms, follow-up B-LUS and CEUS examinations may be helpful for a possible retrospective diagnosis of peripheral pulmonary infarction suggestive of PE.

Contrast-enhanced ultrasound is helpful for differentiating benign from malignant parietal pleural lesions.

INTRODUCTION: To describe the value of contrast-enhanced ultrasound (CEUS) for the differentiation of malignant from benign parietal pleural lesions (PPLs). MATERIALS AND METHODS: From November 2005 to June 2019, 63 patients with histologically/cytologically confirmed PPLs were investigated by CEUS. On CEUS, the extent of enhancement (EE; marked or reduced/absent) and the homogeneity of enhancement (HE; homogeneous or inhomogeneous) were analyzed retrospectively. RESULTS: In total, 24/63 lesions were benign, and 39/63 lesions were malignant. On CEUS, 11/24 benign and 36/39 malignant lesions showed a marked enhancement. A marked enhancement was significantly more frequently associated with malignancy compared with benign lesions (p < 0.001). In five cases, due to the absence of enhancement, it was not possible to determine the HE. In the remaining cases, 9/20 benign and 19/38 malignant lesions showed an inhomogeneous enhancement (p = 0.79). CONCLUSION: On CEUS, marked enhancement was significantly more frequently associated with malignant compared with benign lesions. However, some benign lesions, such as chronic inflammatory processes, may also show a marked enhancement. Therefore, the interpretation of perfusion patterns in these lesions must always take into account the clinical background of the patient.

Mediastinal Masses in Contrast-Enhanced Ultrasound - Retrospective Analysis of 58 Cases.

OBJECTIVES: To determine contrast enhancing features of mediastinal masses (ML) using transcutaneous contrast-enhanced ultrasound (CEUS). METHODS: Retrospective analysis of n = 58 patients with histologically confirmed ML, which were examined in the period from October 2005 to February 2018 using transcutaneous B-mode ultrasound and CEUS. In n = 29 (50%) histological confirmation was performed by ultrasound guided core-needle biopsy. The lesions were evaluated using CEUS in regard to the enhancement pattern (hyper-, iso-, hypoenhancement, non-enhancement, homogenous, inhomogenous) compared to enhancement of the spleen as an in vivo reference. RESULTS: N = 53 (91.4%) of ML were malignant (m) (lymphoma n = 36, metastasis n = 11, thymoma n = 2, teratoma n = 1, sarcoma n = 2, seminoma n = 1). In n = 5 (8.6%) cases there was a benign (b) histology (thyroid tissue n = 2, thymus residue n = 1, ganglioneurinoma n = 1, scar tissue: n = 1). In ultrasound, n = 53 (91.4%; (48 = m, 5 = b)) were hypoechoic, n = 5 (8.6%, (5 = m,0 = b)) hyperechoic. In CEUS, n = 35 lesions presented an arterial isoenhancement (60.3%; 33 = m, 2 = b). An arterial hypoenhancement had n = 21 (36.2%, (20 = m,1 = b)), and no enhancement showed n = 2 (3.5%, (0 = m, 2 = b) of the ML. A parenchymal isoenhancement was observed in n = 1 (1.7%, (1 = m, 0 = b)), a hypoenhancement in n = 54 (93.1%; 51 = m, 3 = b) of the patients and almost no enhancement in n = 3 ML (5.2%, (1 = m, 2 = b).) The enhancement was homogeneous in n = 26 (44.8%, (25 = m,1 = b)) cases, in n = 31 (53.5%, (28 = m,3 = b)) inhomogeneous and n = 1 (1.7%) benign lesion was exclusively cystic. CONCLUSION: In CEUS, mediastinal tumor formations showed variable arterial enhancement, followed by parenchymal hypoenhancement (wash-out).

Perfusion Patterns of Peripheral Pulmonary Lesions in COVID-19 Patients Using Contrast-Enhanced Ultrasound (CEUS): A Case Series.

PURPOSE: To describe perfusion patterns of peripheral pulmonary lesions (PPLs) in COVID-19 patients using contrast-enhanced ultrasound (CEUS). PATIENTS AND METHODS: From April 2020 until July 2020, 11 consecutive patients with RT-PCR-confirmed COVID-19 and PPLs sized over 5 mm were investigated by B-mode ultrasound (B-US) and CEUS. The homogeneity of enhancement (homogeneous and inhomogeneous) was examined retrospectively using CEUS. An inhomogeneous enhancement was defined as a perfused lesion with coexisting non-perfused areas (NPA). RESULTS: On B-US, all 11 patients showed an interstitial syndrome (B-lines) with PPLs between 0.5 and 6 cm. On CEUS, all cases showed peripheral NPA during the complete CEUS examination. One patient underwent a partial lung resection with subsequent histopathological examination. The histological examination showed vasculitis, microthrombus in the alveolar capillary, and small obliterated vessels. CONCLUSION: In our case series, PPLs in patients with RT-PCR-confirmed COVID-19 infection presented a CEUS pattern with NPA during the complete CEUS examination. Our findings suggest a peripheral pulmonary perfusion disturbance in patients with COVID-19 infection. In 1 case, the histopathological correlation with the perfusion disturbance in the PPL was proven.

Use of Ultrasound in the Diagnostic Work-Up of Adult Intussusception - A Multicenter Retrospective Analysis.

PURPOSE: To evaluate the use of ultrasound (US) in the diagnostic work-up of adult intussusception (AI). METHODS: This multicenter study includes 26 consecutive patients diagnosed with AI between January 2010 and November 2017. A retrospective chart analysis was conducted with a focus on abdominal US findings and diagnostic accuracy of different imaging modalities (ultrasound, computed tomography (CT), magnetic resonance imaging). If available, surgical and pathological findings served as the gold standard (76.9 %). US examiners certified according to DEGUM grade 2 or 3 were classified as experts. Otherwise, they were regarded to have basic skills. RESULTS: During diagnostic work-up, 92.3 % underwent abdominal US. US was the first-line imaging modality in 88.5 % of cases. The accuracy regarding the detection of AI (85 %), correct localization (95 %) and detection of complications (100 %) was excellent and comparable with CT (81 %, 90.5 %, and 91.7 %) when performed by experts. 72.7 % of tumorous lead points were detected by experienced examiners. In contrast, AI was detected in only 45.5 % of cases by examiners with basic skills. AI was diagnosed prior to surgery in all patients. CONCLUSION: US is reliable in the diagnostic work-up of AI when performed by experienced examiners with high-quality equipment. US, CT and MRI should be used in a complementary fashion since combination provides excellent sensitivity regarding the detection and correct localization of AI as well as the detection of complications. The impact of real-time imaging is illustrated by supplementary videos.

Differential diagnosis of small solid pancreatic lesions.

BACKGROUND AND AIMS: Pancreatic ductal adenocarcinoma (PDAC) is typically diagnosed at a late stage. Little is known about the incidental finding of early-stage PDAC. The aim of the current study was to determine the etiology of small solid pancreatic lesions (≤15 mm) to optimize clinical management. METHODS: Inclusion criterion for the retrospective study analysis was the incidental finding of primarily undetermined small solid pancreatic lesions ≤15 mm in 394 asymptomatic patients. Final diagnoses were based on histology or cytology obtained by imaging-guided biopsy (and at least 12-month follow-up) and/or surgery. Contrast-enhanced US or contrast-enhanced EUS was performed in 219 patients. RESULTS: The final diagnoses of 394 patients were as follows: 146 PDACs, 156 neuroendocrine tumors, 28 metastases into the pancreas from other primary sites, and 64 various other etiologies. Contrast-enhanced US allowed differential diagnosis of PDAC and non-PDAC in 189 of 219 patients (86%). CONCLUSIONS: Approximately 40% of patients with small solid pancreatic lesions had very early stage PDAC. Approximately 60% of small solid pancreatic lesions ≤15 mm are not PDAC and, therefore, do not require radical surgery. Without preoperative diagnosis, an unacceptably large proportion of patients would be exposed to radical surgery with significant morbidity and mortality.

Intracavitary contrast-enhanced ultrasound in abscess drainage--feasibility and clinical value.

OBJECTIVE: To evaluate the usefulness of intracavitary-applied contrast-enhanced ultrasound (ICCEUS) with BR1 in ultrasound-guided puncture and drainage of abdominal and pelvic abscesses. MATERIAL AND METHODS: A total of 71 consecutive patients received ICCEUS after placement of a drainage catheter or a needle in abdominal or pelvic abscesses. Portions of 0.1 ml of BR1 and 20 ml of saline were injected through the drainage catheter or needle. Ultrasound recordings were evaluated to answer the following questions: correct placement of the catheter by showing enhancement in the cavity and the drain - ICCEUS findings suggesting incomplete enhancement in all abscess cavities - enhancement in non-abscess structures. RESULTS: About 52% of patients had liver, 14% of patients had intraperitoneal, 11% had subphrenic, 14% had retroperitoneal, 6% had splenic, and 4% had pelvic abscesses. The majority of the patients received drain placement with 10-F using trocar technique. Enhancement in the drain or needle was seen in all patients. In 2% of patients, during the initial approach, a dislodgment of the catheter from the abscess cavity was diagnosed. Due to non-enhancing abscess compartments, in 36% of the patients more than one drainage treatment was necessary at the time of the first approach. In 14% of the patients communication with surrounding structures was diagnosed. Additional treatment resulted in 4% of cases. CONCLUSION: ICCEUS was helpful in all patients to confirm correct placement of drain or puncture needle. In 40% of patients, as a consequence of ICCEUS, additional therapy was scheduled, either additional drainage or abscess puncture, endoscopic retrograde drainage of the biliary or pancreatic duct or thoracic intervention.

Lung Ultrasound and Pleural Artifacts: A Pictorial Review.

Lung ultrasound is a well-established diagnostic approach used in detecting pathological changes near the pleura of the lung. At the acoustic boundary of the lung surface, it is necessary to differentiate between the primary visualization of pleural parenchymal pathologies and the appearance of secondary artifacts when sound waves enter the lung or are reflected at the visceral pleura. The aims of this pictorial essay are to demonstrate the sonographic patterns of various pleural interface artifacts and to illustrate the limitations and pitfalls of the use of ultrasound findings in diagnosing any underlying pathology.

Ultrasound during Advanced Life Support-Help or Harm?

Ultrasound is used in cardiopulmonary resuscitation (CPR) and advanced life support (ALS). However, there is divergence between the recommendations of many emergency and critical care societies who support its use and the recommendations of many international resuscitation organizations who either recommend against its use or recommend it only in limited circumstances. Ultrasound offers potential benefits of detecting reversable causes of cardiac arrest, allowing specific interventions. However, it also risks interfering with ALS protocols and increasing unhelpful interventions. As with many interventions in ALS, the evidence base for ultrasound use is weak, and well-designed randomized trials are needed. This paper reviews the current theory and evidence for harms and benefits.

Controversies in Endoscopic Ultrasound-Guided Biliary Drainage.

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.

WFUMB Guideline/Guidance on Liver Multiparametric Ultrasound: Part 1. Update to 2018 Guidelines on Liver Ultrasound Elastography.

The World Federation for Ultrasound in Medicine and Biology (WFUMB) endorsed the development of this document on multiparametric ultrasound. Part 1 is an update to the WFUMB Liver Elastography Guidelines Update released in 2018 and provides new evidence on the role of ultrasound elastography in chronic liver disease. The recommendations in this update were made and graded using the Oxford classification, including level of evidence (LoE), grade of recommendation (GoR) and proportion of agreement (Oxford Centre for Evidence-Based Medicine [OCEBM] 2009). The guidelines are clinically oriented, and the role of shear wave elastography in both fibrosis staging and prognostication in different etiologies of liver disease is discussed, highlighting advantages and limitations. A comprehensive section is devoted to the assessment of portal hypertension, with specific recommendations for the interpretation of liver and spleen stiffness measurements in this setting.

WFUMB Guidelines/Guidance on Liver Multiparametric Ultrasound. Part 2: Guidance on Liver Fat Quantification.

The World Federation for Ultrasound in Medicine and Biology (WFUMB) has promoted the development of this document on multiparametric ultrasound. Part 2 is a guidance on the use of the available tools for the quantification of liver fat content with ultrasound. These are attenuation coefficient, backscatter coefficient, and speed of sound. All of them use the raw data of the ultrasound beam to estimate liver fat content. This guidance has the aim of helping the reader in understanding how they work and interpret the results. Confounding factors are discussed and a standardized protocol for measurement acquisition is suggested to mitigate them. The recommendations were based on published studies and experts' opinion but were not formally graded because the body of evidence remained low at the time of drafting this document.

The Role of Thoracic Ultrasound for Diagnosis of Diseases of the Chest Wall, the Mediastinum, and the Diaphragm-Narrative Review and Pictorial Essay.

The diagnostic capabilities of ultrasound extend far beyond the evaluation of the pleural space and lungs. Sonographic evaluation of the chest wall is a classic extension of the clinical examination of visible, palpable, or dolent findings. Unclear mass lesions of the chest wall can be differentiated accurately and with low risk by additional techniques such as color Doppler imaging, contrast-enhanced ultrasound, and, in particular, ultrasound-guided biopsy. For imaging of mediastinal pathologies, ultrasound has only a complementary function but is valuable for guidance of percutaneous biopsies of malignant masses. In emergency medicine, ultrasound can verify and support correct positioning of endotracheal tubes. Diaphragmatic ultrasound benefits from the real-time nature of sonographic imaging and is becoming increasingly important for the assessment of diaphragmatic function in long-term ventilated patients. The clinical role of thoracic ultrasound is reviewed in a combination of narrative review and pictorial essay.

The diagnostic value of Doppler Resistive Index in the differential diagnosis of focal liver lesions.

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.

Acoustic Radiation Force Impulse (ARFI) Elastography of Focal Splenic Lesions: Feasibility and Diagnostic Potential.

PURPOSE: Nontraumatic focal splenic lesions (FSL) are rare, and the need for tissue diagnosis must be weighed against the very high risk of bleeding after a splenic biopsy. The aim of this study was to explore the feasibility and diagnostic potential of acoustic radiation force impulse (ARFI) elastography as a noninvasive method for different benign and malignant FSLs. No human studies on the elastographic characteristics of FSL exist. METHODS: This was a retrospective analysis of 34 patients with FSLs, who underwent abdominal B-mode ultrasound (B-US), contrast-enhanced ultrasound (CEUS), and standardized ARFI examinations between October 2021 and December 2022 at our university hospital. The inclusion criteria were: (i) FSL size ≥ 1 cm; (ii) 10 valid ARFI measurements of the FSL, as well as of the normal splenic parenchyma (NSP) as an in vivo reference; and (iii) diagnostic confirmation of FSL etiology based on histological examination (8/34; 23.5%) or clinical evaluation, which included a clinical and sonographic follow-up (FU), CEUS morphology, and/or morphology on cross-sectional imaging (26/34; 76.5%). CEUS was performed on all patients and the FSLs were classified according to the current guidelines; cross-sectional imaging was available for 29/34 (85.3%). The mean FU duration was 25.8 ± 30.5 months. The mean ARFI velocity (MAV) of the FSL (MAVL), the NSP (MAVP), and the ratio of the MAVL to the MAVP (MAVL/P) were calculated and compared. RESULTS: Of the 34 FSLs, 13 (38.2%) were malignant (mFSL) and 21 (61.8%) were benign (bFSL). The MAVL of all 34 FSLs (2.74 ± 0.71 m/s) was lower than the MAVP (3.20 ± 0.59 m/s), p = 0.009, with a mean MAVL/P ratio of 0.90 ± 0.34. No significant differences in the MAVL were observed between the mFSL (2.66 ± 0.67 m/s) and bFSL (2.79 ± 0.75 m/s). There were also no significant differences between the MAVP in patients with mFSL (3.24 ± 0.68 m/s) as compared to that in the patients with bFSL (3.18 ± 0.55 m/s). Likewise, the MAV L/P ratio did not differ between the mFSL (0.90 ± 0.41 m/s) and bFSL (0.90 ± 0.30 m/s) groups. CONCLUSION: ARFI elastography is feasible in evaluating the stiffness of FSLs. The lesions' stiffness was lower than that of the NSP, regardless of the FSL etiology. However, differentiation between benign and malignant FSL with the help of this elastographic method does not appear possible. Larger prospective studies are needed to validate these findings.

Comments and illustrations of the WFUMB CEUS liver guidelines: Rare focal liver lesions - infectious (bacterial).

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.

Comments and illustrations of the WFUMB CEUS liver guidelines: Rare benign focal liver lesion, part II.

It is important to be familiar with the typical imaging features of the uncommon or even extremely rare focal liver lesions (FLL). Current guidelines of the World Federation for Ultrasound in Medicine and Biology (WFUMB) is aimed at assessing the usefulness of contrast enhanced ultrasound (CEUS) in the management of various FLL. In this review, we aim to summarize the ultrasound and CEUS characteristics with literature review of some extremely rare benign FLL, which might be helpful for improving diagnostic efficiency clinically.

Assessment Methods in Medical Ultrasound Education.

Medical schools are increasingly incorporating ultrasound into undergraduate medical education. The global integration of ultrasound into teaching curricula and physical examination necessitates a strict evaluation of the technology's benefit and the reporting of results. Course structures and assessment instruments vary and there are no national or worldwide standards yet. This systematic literature review aims to provide an up-to-date overview of the various formats for assessing ultrasound skills. The key questions were framed in the PICO format (Population, Intervention, Comparator, and Outcome). A review of literature using Embase, PubMed, Medline, Cochrane and Google Scholar was performed up to May 2021, while keywords were predetermined by the authors. Inclusion criteria were as follows: prospective as well as retrospective studies, observational or intervention studies, and studies outlining how medical students learn ultrasound. In this study, 101 articles from the literature search matched the inclusion criteria and were investigated. The most frequently used methods were objective structured clinical examinations (OSCE), multiple choice questions, and self-assessments via questionnaires while frequently more than one assessment method was applied. Determining which assessment method or combination is ideal to measure ultrasound competency remains a difficult task for the future, as does the development of an equitable education approach leading to reduced heterogeneity in curriculum design and students attaining equivalent skills.