[Lung ultrasonography in COVID-19 pneumonia]. / Sonographische Bildgebung der Lunge bei COVID-19.

BACKGROUND: Point-of-care ultrasound (POCUS) of the lung in patients with COVID-19 plays a key role in the emergency room and intensive care unit. Lung ultrasound is able to depict typical pulmonary findings of COVID-19 and is therefore suitable for diagnosis and follow-up of these patients. CLINICAL/METHODOLOGICAL ISSUE: Lung ultrasound in COVID-19 patients in the emergency room and intensive care unit. STANDARD RADIOLOGICAL METHODS: Computed tomography (low-dose CT) and X­ray of the lung. METHODOLOGICAL INNOVATIONS: Lung ultrasound in COVID-19 patients. RECOMMENDATIONS: Lung ultrasound in patients with COVID-19 offers similar performance as CT and is superior when compared to X­ray in evaluating pneumonia and acute respiratory distress syndrome (ARDS). Lung ultrasound plays an important role in the emergency room and intensive care unit. POCUS reduces exposure to radiation, therapy delays, and minimizes transport of high-risk patients. Differential diagnoses can also be clarified.

[Modern sonographic imaging of abdominal neuroendocrine tumors]. / Moderne sonographische Bildgebung bei neuroendokrinen Tumoren des Abdomens.

BACKGROUND: Radiological and nuclear medical diagnostics play an important role in the work-up of patients with gastroenteropancreatic neuroendocrine tumors (GEP-NET). The sonographic examination, including contrast-enhanced examination, depicts an initial imaging modality to screen for NET. This report describes the sonomorphological behavior of ileal and pancreatic NET as well as hepatic metastases from NET. CLINICAL/METHODICAL ISSUE: Sonographic evaluation of NET of the small intestine, pancreas and neuroendocrine hepatic metastases. STANDARD RADIOLOGICAL METHODS: Contrast-enhanced computed tomography (CT) or magnetic resonance imaging (MRI), unenhanced ultrasonography. METHODICAL INNOVATIONS: Contrast-enhanced ultrasound (CEUS). PERFORMANCE: CEUS supports unenhanced ultrasound in the detection of NET and the differential diagnosis of unclear lesions, and is more sensitive for liver metastases (sensitivity according to the literature, 99% vs. 68%) PRACTICAL RECOMMENDATIONS: CEUS allows initial evaluation of NET and differentiation of benign vs. malignant lesions. Nevertheless, CEUS cannot replace more elaborate imaging modalities like CT or MRI for thorough staging examinations.

Evaluation of renal lesions using contrast-enhanced ultrasound (CEUS); a 10-year retrospective European single-centre analysis.

OBJECTIVE: To investigate the usefulness of contrast-enhanced ultrasound (CEUS) in the evaluation of renal masses. METHODS: This study included 255 patients with renal masses. Ages ranged from 18-86 years. CEUS was used for determining malignancy or benignancy and findings were correlated with the histopathological outcome. Out of 255 lesions, 212 lesions were malignant (83.1%) and 43 were benign (16.9%). Diagnostic accuracy was tested using the histopathological diagnosis as the gold standard. RESULTS: CEUS showed a sensitivity of 99.1% [95% confidence interval (CI): 96.7%, 99.9%], a specificity of 80.5% (CI: 65.1%, 91.2%), a positive predictive value of 96.4% (CI: 93.0%, 98.4%) and a negative predictive value of 94.3% (CI: 80.8%, 99.3%). Kappa for diagnostic accuracy was κ = 0.85 (CI: 0.75, 0.94). Of 212 malignant lesions, 200 renal cell carcinomas and 12 other malignant lesions were diagnosed. Out of 43 benign lesions, 10 angiomyolipomas, 3 oncocytomas, 8 renal cysts and 22 other benign lesions were diagnosed. CONCLUSION: CEUS is an useful method to differentiate between malignant and benignant renal lesions. To date, to our knowledge, this is the largest study in Europe for the evaluation of renal lesions using CEUS with a histopathological validation. KEY POINTS: • CEUS helps clinicians detect and characterise unclear solid and cystic renal lesions • CEUS shows a high diagnostic accuracy in the characterization of these lesions • Proper surgical treatment or follow-up can be given with better diagnostic confidence.

[Contrast-enhanced ultrasound (CEUS) and image fusion for procedures of liver interventions]. / Kontrastmittelsonographie (CEUS) und Bildfusion zur Durchführung von Leberinterventionen.

CLINICAL/METHODICAL ISSUE: Contrast-enhanced ultrasound (CEUS) is becoming increasingly important for the detection and characterization of malignant liver lesions and allows percutaneous treatment when surgery is not possible. Contrast-enhanced ultrasound image fusion with computed tomography (CT) and magnetic resonance imaging (MRI) opens up further options for the targeted investigation of a modified tumor treatment. METHODICAL INNOVATIONS: Ultrasound image fusion offers the potential for real-time imaging and can be combined with other cross-sectional imaging techniques as well as CEUS. PERFORMANCE: With the implementation of ultrasound contrast agents and image fusion, ultrasound has been improved in the detection and characterization of liver lesions in comparison to other cross-sectional imaging techniques. In addition, this method can also be used for intervention procedures. The success rate of fusion-guided biopsies or CEUS-guided tumor ablation lies between 80 and 100% in the literature. ACHIEVEMENTS: Ultrasound-guided image fusion using CT or MRI data, in combination with CEUS, can facilitate diagnosis and therapy follow-up after liver interventions. PRACTICAL RECOMMENDATIONS: In addition to the primary applications of image fusion in the diagnosis and treatment of liver lesions, further useful indications can be integrated into daily work. These include, for example, intraoperative and vascular applications as well applications in other organ systems.

[CEUS-Use in testicular pathologies]. / CEUS ­ Anwendung am Hoden.

BACKGROUND: The work-up of scrotal diseases forms an essential part of daily work in urology. Sonography plays an important role in the diagnostic process, due to its wide availability and feasibility. OBJECTIVES: Advantages of modern contrast-enhanced ultrasound (CEUS) are illustrated using examples of common testicular pathologies. MATERIALS AND METHODS: Relevant studies regarding the application of CEUS on testicular pathologies are evaluated. PubMed and Medline were screened for reviews and clinical trials. RESULTS: In the differentiation of benign and malignant testicular lesions, contrast medium uptake, e. g. can exclude a hemorrhagic testicular cyst. A differentiation between benign and malignant testicular lesions due to pure enhancement is currently not possible. Evaluation of testicular abscesses, infarctions and infections depends on the assessment of vascularization. Following a scrotal trauma, evaluation of enhancement can distinguish between vital and non-vital areas. A complete absence of perfusion may support the diagnosis of testicular torsion. CONCLUSION: CEUS is a feasible instrument in the diagnostic work-up of testicular pathologies. Results from previous studies are promising. Regarding the application in cases of scrotal trauma, the method could play an essential role in the future. With regard to a classification of unclear testicular lesions, further studies with a larger number of patients are needed in order to confirm previously described perfusion patterns.

[Reliable diagnosis of cystic renal lesions]. / Sichere Diagnostik zystischer Nierenläsionen.

CLINICAL/METHODICAL ISSUE: Cystic renal lesions are commonly seen during routine ultrasound examinations of the abdomen. STANDARD RADIOLOGICAL METHODS: Some cystic renal lesions cannot be sufficiently characterized using native ultrasound. In these cases additional imaging might be necessary. METHODICAL INNOVATIONS: Contrast-enhanced ultrasound (CEUS) is a reliable imaging modality to characterize cystic renal lesions. Contrast enhancement of septations and the cystic wall are visualized in high resolution. This information helps to categorize the cystic renal lesions applying the CEUS Bosniak classification. This classification helps to estimate the probability of a malignant etiology of cystic renal lesions. PERFORMANCE: Using CEUS, cystic renal lesions can be characterized with a high sensitivity and specificity. ACHIEVEMENTS: The advantages of CEUS include that there is no effect on the function of the kidneys or the thyroid gland and no radiation exposure. In some cases, additional cross-sectional imaging is necessary to optimize diagnostic accuracy. PRACTICAL RECOMMENDATIONS: CEUS is a helpful imaging modality to characterize cystic renal lesions, to avoid unnecessary follow-ups and to detect malignant cystic renal lesions.

[CEUS-diagnosis of benign liver lesions]. / CEUS ­ Diagnostik benigner Leberläsionen.

CLINICAL/METHODICAL ISSUE: Focal liver lesions are commonly seen during routine ultrasound examinations. STANDARD RADIOLOGICAL METHODS: With native ultrasound there are lesions that cannot be sufficiently characterized. In these cases additional imaging might be necessary. METHODICAL INNOVATIONS: With contrast-enhanced ultrasound (CEUS), focal liver lesions can be characterized with high diagnostic accuracy. After the ultrasound contrast agent has been injected into a peripheral vein, the examiner saves video loops of the arterial, portal venous and late contrast phases. Combing the findings of native and contrast-enhanced ultrasound allows not only assessment of the etiology as benign or malignant but also detailed characterization of the focal liver lesion in most cases. PERFORMANCE: Using CEUS, focal liver lesions can be characterized with a sensitivity of over 95% and a specificity of about 83%. ACHIEVEMENTS: The advantages of CEUS include that there is no radiation exposure and that the ultrasound contrast agent has no effects on the function of the liver, kidneys or the thyroid gland. The main limiting factors for CEUS are bowel gas and obesity of the patient. PRACTICAL RECOMMENDATIONS: CEUS can visualize micro- and macrovascularization of benign focal liver lesions in real time. It is a useful imaging modality in unclear cases.

[CEUS-Diagnostic of malignant liver lesions]. / CEUS ­ Diagnostik maligner Leberläsionen.

CLINICAL/METHODICAL ISSUE: Cross-sectional modalities or conventional ultrasound are not always able to sufficiently identify and characterize malignant liver lesions. STANDARD RADIOLOGICAL METHODS: The evaluation of malignant liver lesions in conventional ultrasound relies on echostructure, shape and borders, but often warrants additional contrast-enhanced computed tomography (CT) or magnetic resonance imaging (MRI) studies. METHODICAL INNOVATIONS: Contrast-enhanced ultrasound (CEUS) is a relatively safe imaging technique used for the detection and characterization of malignant liver lesions. The use of a second-generation contrast agent in dynamic real-time imaging allows the visualization of vascularization in any kind of liver lesion as well as liver perfusion during the arterial, portal venous and late phase. PERFORMANCE: Due to the different enhancement patterns, it is possible to differentiate a liver lesion with high diagnostic accuracy (over 90%). ACHIEVEMENTS: CEUS is a helpful complementary technique to cross-sectional imaging for the evaluation of unclear liver lesions and may frequently obviate additional contrast-enhanced MRI or CT studies. PRACTICAL RECOMMENDATIONS: CEUS enables the detection and characterization of liver lesions in real time.

[CEUS-diagnostic workup of cystic renal lesions]. / CEUS ­ Diagnostik zystischer Nierenläsionen.

CLINICAL/METHODICAL ISSUE: Cystic renal lesions are common incidental findings in radiological imaging and they should be adequately examined to be able to characterize them as benign or malignant. STANDARD RADIOLOGICAL METHODS: It is not always possible to sufficiently characterize cystic renal lesion solely using native B­mode sonography and color-Doppler sonography. METHODICAL INNOVATIONS: Using contrast-enhanced ultrasound (CEUS), it is possible to dynamically evaluate the perfusion of cystic renal lesions and to characterize the potential malignancy of these lesions using the Bosniak classification in order to give recommendations regarding further work-up. CEUS can also be used in patients with contraindications for other radiological imaging modalities as it uses a contrast agent with almost no side effects. PERFORMANCE: Using CEUS, cystic renal lesions can be reliably characterized with a diagnostic accuracy greater than 90%. ACHIEVEMENTS: CEUS is a useful method in diagnosing and characterizing unclear cystic renal lesions and should always be considered as a viable diagnostic tool. PRACTICAL RECOMMENDATIONS: CEUS should always be performed in initially unclear cases and is a useful additional tool for the diagnosis and characterization of unclear cystic renal lesions.

[Contrast-enhanced ultrasound (CEUS) of the liver : Critical evaluation of use in clinical routine diagnostics]. / Kontrastverstärkter Ultraschall (CEUS) der Leber : Kritische Bewertung des Einsatzes in der Routinediagnostik.

CLINICAL/METHODICAL ISSUE: Focal liver lesions are common incidental findings in abdominal ultrasound diagnostics. STANDARD RADIOLOGICAL METHODS: Characterization of focal liver lesions solely based on b­mode and color duplex is not feasible in all cases. METHODICAL INNOVATIONS: Using contrast-enhanced ultrasound (CEUS) it is possible to dynamically visualize the vascularization of focal liver lesions, which enables the characterization of benign and malignant liver tumors. The advantages of CEUS are that ultrasound contrast media do not show renal, hepatic or cardiac toxicity and do not influence the thyroid gland. The approach by fusion of CEUS and contrast-enhanced cross-sectional imaging combines the advantages of both imaging modalities. PERFORMANCE: Using CEUS focal liver lesions can be characterized with a diagnostic accuracy greater than 90%. ACHIEVEMENTS: The use of CEUS has become an important imaging modality to evaluate unclear liver lesions. PRACTICAL RECOMMENDATIONS: The use of CEUS provides vital information as a supplement to cross-sectional imaging and it has become an important tool in therapy planning, control and monitoring of malignant liver lesions.

[Sonoelastography in daily clinical routine]. / Ultraschallelastographie in der klinischen Routinediagnostik.

CLINICAL ISSUE: In the daily clinical routine characterization of focal lesions using native B­mode classical ultrasound and color Doppler can be difficult or insufficient; therefore, additional diagnostic information must be taken into consideration. STANDARD RADIOLOGICAL METHODS: Standard radiological methods in the daily clinical routine include native B­mode ultrasound and color Doppler ultrasound. METHODICAL INNOVATIONS: Using sonoelastography it is possible to evaluate and characterize tissue properties and focal lesions regarding their stiffness to acquire additional information on a noninvasive basis. PERFORMANCE: Sonoelastography enables the differentiation between benign and malignant lesions especially in organs that can be easily evaluated using ultrasound. This particularly includes the liver, the thyroid gland, the breasts and the testicles. Regarding the liver, sonoelastography techniques can also be used for evaluation of the tissue flexibility in the diagnostics of fibrosis and cirrhosis. ACHIEVEMENTS: Nowadays, elastography is implemented into every modern ultrasound system and has been established as a supplementary examination technique to the conventional ultrasound techniques. PRACTICAL RECOMMENDATIONS: Sonoelastography should be used in cases with unclear findings as an additional noninvasive tool for the differentiation between benign and malignant lesions.

Contrast-Enhanced Ultrasound (CEUS) of the Kidneys by Using the Bosniak Classification.

Ultrasound is the most used interdisciplinary non-ionizing imaging technique in clinical routine. Therefore, ultrasound has a special value in the diagnosis and monitoring of cystic renal lesions, which can be classified as non-complicated or complicated and by means of occurrence as solitary or multifocal lesions. The Bosniak classification (I-IV) classifies renal cysts in 5 different categories with the help of ultrasound and computed tomography image criteria and is used for decisions of further clinical treatment. Additionally to normal native B-mode sonography, several new methods are in clinical use to improve diagnostic accuracy of unclear cases. Contrast enhanced ultrasound and MRI/CT are able to find and characterize difficult pathologies. This review explains the most important pathologies of cystic lesions of the kidney and stresses the different imaging methods of native B-mode sonography and the new techniques of contrast enhanced ultrasound.

[Possibilities of sonographic image fusion: Current developments]. / Möglichkeiten der sonographischen Fusionsbildgebung: Aktuelle Entwicklungen.

CLINICAL/METHODICAL ISSUE: For diagnostic and interventional procedures ultrasound (US) image fusion can be used as a complementary imaging technique. METHODICAL INNOVATIONS: Image fusion has the advantage of real time imaging and can be combined with other cross-sectional imaging techniques. PERFORMANCE: With the introduction of US contrast agents sonography and image fusion have gained more importance in the detection and characterization of liver lesions. ACHIEVEMENTS: Fusion of US images with computed tomography (CT) or magnetic resonance imaging (MRI) facilitates the diagnostics and postinterventional therapy control. PRACTICAL RECOMMENDATIONS: In addition to the primary application of image fusion in the diagnosis and treatment of liver lesions, there are more useful indications for contrast-enhanced US (CEUS) in routine clinical diagnostic procedures, such as intraoperative US (IOUS), vascular imaging and diagnostics of other organs, such as the kidneys and prostate gland.

[New Applications and Indications for Contrast-Enhanced Sonography in Endovascular Aortic Repair]. / Neue Applikationen und Indikationen der Kontrastmittelsonografie im Rahmen des Aortenstentings.

After edovascular repair of infrarenal aortic aneurysms (EVAR) endoleaks may occur necessitating further therapy. Therefore a reliable method for follow-up imaging after EVAR for detection and control of endoleaks is of high importance. Contrast-enhanced sonography (CEUS) does not require the application of nephrotoxid contrast media and does not stress the patient. CEUS is increasingly used and enables a quick, non-invasive follow-up examination for patient after EVAR. In addition, interventions as therapy for endoleaks may be executed using ultrasound. Initial experience with CEUS-guided aortic stenting shows that the amount of contrast media as well as X-ray time may be reduced.

[Elastography as an additional tool in breast sonography. Technical principles and clinical applications]. / Elastographie als Zusatzmodalität der Mammasonographie. Technische Grundlagen und klinische Anwendungsmöglichkeiten.

In recent years the use of elastography in addition to sonography has become a routine clinical tool for the characterization of breast masses. Whereas free hand compression elastography results in qualitative imaging of tissue stiffness due to induced compression, shear wave elastography displays quantitative information of tissue displacement. Recent studies have investigated the use of elastography in addition to sonography and improvement of specificity in differentiating benign from malignant breast masses could be shown. Therefore, additional use of elastography could help to reduce the number of unnecessary biopsies in benign breast lesions especially in category IV lesions of the ultrasound breast imaging reporting data system (US-BI-RADS).

CT perfusion technique for assessment of early kidney allograft dysfunction: preliminary results.

OBJECTIVES: To assess the benefit of quantitative computed tomography (CT) perfusion for differentiating acute tubular necrosis (ATN) and acute rejection (AR) in kidney allografts. METHODS: Twenty-two patients with acute kidney allograft dysfunction caused by either AR (n = 6) or ATN (n = 16) were retrospectively included in the study. All patients initially underwent a multiphase CT angiography (CTA) protocol (12 phases, one phase every 3.5 s) covering the whole graft to exclude acute postoperative complications. Multiphase CT dataset and dedicated software were used to calculate renal blood flow. Renal biopsy or clinical course of disease served as the standard of reference. Mean effective radiation dose and mean amount of contrast media were calculated. RESULTS: Renal blood flow values were significantly lower (P = 0.001) in allografts undergoing AR (48.3 ± 21 ml/100 ml/min) compared with those with ATN (77.5 ± 21 ml/100 ml/min). No significant difference (P = 0.71) was observed regarding creatinine level with 5.65 ± 3.1 mg/dl in AR and 5.3 ± 1.9 mg/dl in ATN. The mean effective radiation dose of the CT perfusion protocol was 13.6 ± 5.2 mSv; the mean amount of contrast media applied was 34.5 ± 5.1 ml. All examinations were performed without complications. CONCLUSION: CT perfusion of kidney allografts may help to differentiate between ATN and rejection. KEY POINTS: • Quantitative CT perfusion of renal transplants is feasible. • CT perfusion could help to non-invasively differentiate AR from ATN. • CT perfusion might make some renal biopsies unnecessary.

Guidelines and good clinical practice recommendations for contrast enhanced ultrasound (CEUS) in the liver--update 2012: a WFUMB-EFSUMB initiative in cooperation with representatives of AFSUMB, AIUM, ASUM, FLAUS and ICUS.

Initially, a set of guidelines for the use of ultrasound contrast agents was published in 2004 dealing only with liver applications. A second edition of the guidelines in 2008 reflected changes in the available contrast agents and updated the guidelines for the liver, as well as implementing some non-liver applications. Time has moved on, and the need for international guidelines on the use of CEUS in the liver has become apparent. The present document describes the third iteration of recommendations for the hepatic use of contrast enhanced ultrasound (CEUS) using contrast specific imaging techniques. This joint WFUMB-EFSUMB initiative has implicated experts from major leading ultrasound societies worldwide. These liver CEUS guidelines are simultaneously published in the official journals of both organizing federations (i.e., Ultrasound in Medicine and Biology for WFUMB and Ultraschall in der Medizin/European Journal of Ultrasound for EFSUMB). These guidelines and recommendations provide general advice on the use of all currently clinically available ultrasound contrast agents (UCA). They are intended to create standard protocols for the use and administration of UCA in liver applications on an international basis and improve the management of patients worldwide.

[Interventional sonography of the liver and kidneys]. / Interventionelle Sonographie der Leber und der Niere.

CLINICAL/METHODICAL ISSUE: Optimization of ultrasound guided interventional procedures of the liver and kidneys using new imaging methods. STANDARD RADIOLOGICAL METHODS: Punctures, biopsies, drainage, intraoperative ultrasound, fusion, embolization in correlation with ultrasound and other imaging methods. METHODICAL INNOVATIONS: Real-time-sonography, contrast-enhanced ultrasound (CEUS) and fusion for planning, monitoring and postinterventional control. PERFORMANCE: The use of CEUS enables better detection, characterization and execution of interventional procedures. Fusion facilitates detection. ACHIEVEMENTS: The CEUS procedure is superior for detection and characterization of smaller lesions in comparison to the B scan. Fusion enables the performance of difficult interventional procedures. PRACTICAL RECOMMENDATIONS: The B scan is the standard imaging method but CEUS and fusion could be helpful for smaller lesions.

[MR-guided focused ultrasound. Current and future applications]. / MR-gesteuerter fokussierter Ultraschall. Aktuelle und potenzielle Indikationen.

STANDARD RADIOLOGICAL METHODS: High-intensity focused ultrasound (synonyms FUS and HIFU) under magnetic resonance imaging (MRI) guidance (synonyms MRgFUS and MR-HIFU) is a completely non-invasive technology for accurate thermal ablation of a target tissue while neighboring tissues and organs are preserved. METHODICAL INNOVATIONS: The combination of FUS with MRI for planning, (near) real-time monitoring and outcome assessment of treatment markedly enhances the safety of the procedure. ACHIEVEMENTS: The MRgFUS procedure is clinically established in particular for the treatment of symptomatic uterine fibroids, followed by palliative ablation of painful bone metastases. Furthermore, promising results have been shown for the treatment of adenomyosis, malignant tumors of the prostate, breast and liver and for various intracranial applications, such as thermal ablation of brain tumors, functional neurosurgery and transient disruption of the blood-brain barrier.