Oxygen production from dissociation of Europa's water-ice surface.

Jupiter's moon Europa has a predominantly water-ice surface that is modified by exposure to its space environment. Charged particles break molecular bonds in surface ice, thus dissociating the water to ultimately produce H2 and O2, which provides a potential oxygenation mechanism for Europa's subsurface ocean. These species are understood to form Europa's primary atmospheric constituents. Although remote observations provide important global constraints on Europa's atmosphere, the molecular O2 abundance has been inferred from atomic O emissions. Europa's atmospheric composition had never been directly sampled and model-derived oxygen production estimates ranged over several orders of magnitude. Here, we report direct observations of H2+ and O2+ pickup ions from the dissociation of Europa's water-ice surface and confirm these species are primary atmospheric constituents. In contrast to expectations, we find the H2 neutral atmosphere is dominated by a non-thermal, escaping population. We find 12 ± 6 kg s-1 (2.2 ± 1.2 × 1026 s-1) O2 are produced within Europa's surface, less than previously thought, with a narrower range to support habitability in Europa's ocean. This process is found to be Europa's dominant exogenic surface erosion mechanism over meteoroid bombardment.

Determination and prospective validation of cut-off values for the diagnosis of liver cirrhosis for point shear-wave elastography/acoustic radiation force impulse imaging using the ACUSON Sequoia ultrasound system.

OBJECTIVES: Point shear-wave elastography (pSWE) alias acoustic radiation force impulse (ARFI) imaging is a well-established ultrasound-based technique for the non-invasive assessment of liver tissue stiffness. As cut-off values for liver cirrhosis cannot be transferred from one ultrasound system to another, this study aimed at determining cut-off values for the newly developed Siemens ACUSON Sequoia ultrasound system. METHODS: In a pilot study phase, two independent examiners conducted 10 pSWE measurements in an elasticity phantom and 32 healthy individuals for the determination of inter-examiner agreement. Afterwards, 22 cirrhotic patients and 57 patients with chronic liver disease undergoing liver biopsy underwent pSWE. Patient characteristics and stiffness values were compared for individuals with and without liver cirrhosis. Diagnostic accuracies of cut-off values for the diagnosis of liver cirrhosis were calculated using areas under the receiver operating characteristics analysis and Youden's index. In a subsequent validation study phase, these cut-off values were validated prospectively in 107 cirrhotic and 68 non-cirrhotic patients. RESULTS: Inter-examiner agreement was excellent for measurements in the elasticity phantom (intra-class correlation coefficient [ICC] = 0.998; P  < 0.001), and good for measurements in patients (ICC = 0.844; P  < 0.001). The best cut-off value for the diagnosis of liver cirrhosis was 1.405 m/s with an AUC of 0.872, a sensitivity of 88.2% and a specificity of 88.2% ( P  < 0.001). CONCLUSION: ARFI elastography using the Siemens ACUSON Sequoia showed a good inter-examiner agreement. The optimal cut-off value was lower than the cut-off values described for former generations of ultrasound devices. These preliminary results should be confirmed in larger patient collectives with histology as the reference standard.

[Case report: persistent fever after SARS-CoV-2 infection]. / Fallbericht: Persistierendes Fieber nach SARS-CoV-2-Infektion.

A 44-year-old man had persistent fever following a severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) infection. Because of progressive sinus tachycardia, thyroid hormones were measured which showed hyperthyroidism. Thyroid sonography revealed enlargement of the thyroid gland with hypoechoic areas with blurred margins. We diagnosed subacute granulomatous thyroiditis associated with SARS-CoV­2 infection and initiated therapy with prednisolone. This therapy resulted in rapid improvement of the patient's clinical condition and complete remission after three months.

Real-life assessment of standardized contrast-enhanced ultrasound (CEUS) and CEUS algorithms (CEUS LI-RADS®/ESCULAP) in hepatic nodules in cirrhotic patients-a prospective multicenter study.

OBJECTIVES: Hepatocellular carcinoma (HCC) can be diagnosed non-invasively with contrast-enhanced ultrasound (CEUS) in cirrhosis if the characteristic pattern of arterial phase hyperenhancement followed by hypoenhancement is present. Recent studies suggest that diagnosis based on this "hyper-hypo" pattern needs further refinement. This study compares the diagnostic accuracies of standardized CEUS for HCC according to the current guideline definition and following the newly developed CEUS algorithms (CEUS LI-RADS®, ESCULAP) in a prospective multicenter real-life setting. METHODS: Cirrhotic patients with liver lesions on B-mode ultrasound were recruited prospectively from 04/2018 to 04/2019, and clinical and imaging data were collected. The CEUS standard included an additional examination point after 4-6 min in case of no washout after 3 min. The diagnostic accuracies of CEUS following the guidelines ("hyper-hypo" pattern), based on the examiner's subjective interpretation ("CEUS subjective"), and based on the CEUS algorithms ESCULAP and CEUS LI-RADS® were compared. RESULTS: In total, 470 cirrhotic patients were recruited in 43 centers. The final diagnosis was HCC in 378 cases (80.4%) according to the reference standard (histology 77.4%, MRI 16.4%, CT 6.2%). The "hyper-hypo" pattern yielded 74.3% sensitivity and 63% specificity. "CEUS subjective" showed a higher diagnostic accuracy (sensitivity, 91.5%; specificity, 67.4%; positive predictive value, 92%; negative predictive value, 66%). Sensitivity was higher for ESCULAP (95%) and "CEUS subjective" (91.5%) versus CEUS LI-RADS® (65.2%; p < 0.001). Specificity was highest for CEUS LI-RADS® (78.6%; p < 0.001). CONCLUSIONS: CEUS has an excellent diagnostic accuracy for the non-invasive diagnosis of HCC in cirrhosis. CEUS algorithms may be a helpful refinement of the "hyper-hypo" pattern defined by current HCC guidelines. KEY POINTS: • Contrast-enhanced ultrasound (CEUS) has a high diagnostic accuracy for the non-invasive diagnosis of hepatocellular carcinoma (HCC) in cirrhosis. • The CEUS algorithm ESCULAP (Erlanger Synopsis for Contrast-enhanced Ultrasound for Liver lesion Assessment in Patients at risk) showed the highest sensitivity, whereas the CEUS LI-RADS® (Contrast-Enhanced UltraSound Liver Imaging Reporting and Data System) algorithm yielded the highest specificity. • A standardized CEUS examination procedure with an additional examination point in the late phase, after 4-6 min in lesions with no washout after 3 min, is vital.

Acoustic radiation force impulse (ARFI) elastography of the bowel wall as a possible marker of inflammatory activity in patients with Crohn's disease.

AIM: To evaluate acoustic radiation force impulse (ARFI) shear-wave velocities of the bowel wall in patients with Crohn's disease (CD). MATERIAL AND METHODS: ARFI shear-wave elastography was analysed within the wall of the stomach, terminal ileum, and sigmoid, and correlated with ultrasound signs of activity in CD patients both retrospectively and in a prospective cohort. RESULTS: A total of 77 retrospective and 21 prospective CD patients were included. ARFI elastography in the stomach, the normal ileum, and sigmoid was lower than in ileitis or sigmoiditis. Retrospectively, the ARFI values correlated with the bowel wall thickness and Limberg vascularisation score. Prospectively, there was no correlation between ARFI and bowel wall thickness, Limberg score, clinical activity, or C-reactive protein. A cut-off analysis of 105 ileal ARFI measurements showed a cut-off value of 1.92 m/s for the diagnosis of ileal inflammation with 75.3% sensitivity and 87.5% specificity. CONCLUSION: In patients with CD, ARFI shear-wave velocities show a trend to higher values in inflamed bowel wall thickening on B-mode ultrasound; however, the differences appear small and may not be clinically significant. The factors influencing ARFI measurements of the bowel wall require further investigation.

Diagnostic accuracy and interobserver variability of Dynamic Vascular Pattern (DVP) in primary liver malignancies - A simple semiquantitative tool for the analysis of contrast enhancement patterns.

BACKGROUND: Contrast-enhanced ultrasound (CEUS) is a valuable tool in the diagnostic approach of focal liver lesions, but occasionally subjective and observer-dependent. Semiquantitative evaluation of dynamic CEUS (DCEUS) with standardised software programmes such as Dynamic Vascular Pattern (DVP) could help to improve diagnostic accuracy and objectivity in liver tumour assessment. OBJECTIVES: The present study aimed at evaluation of diagnostic accuracy of DVP in a clinical setting. MATERIALS AND METHODS: DVP images of 52 focal liver lesions [30 hepatocellular carcinomas (HCCs), 15 intrahepatic cholangiocellular carcinomas (ICCs), 7 focal nodular hyperplasias (FNHs)] were analysed by four blinded observers with different levels of CEUS-experience. Diagnostic accuracies for the assessment of dignity and entity were evaluated. RESULTS: Mean sensitivity, specificity, positive and negative predictive value for detection of malignancy with DVP were 48.4% /67.8% /92.7% and 29.3%, respectively. Total diagnostic accuracies for dignity/entity were 63.9% /38.5% (HCC: 58.3% /25.8%; ICC: 73.3% /50%; FNH: 67.9% /67.9%). Interreader-agreement was moderate (κ= 0.42-0.58). Differential diagnosis between ICC and HCC was most challenging. CONCLUSION: Although developed to improve diagnostic accuracy and objectivity in the assessment of focal liver lesions, DVP alone seems insufficient for differential diagnosis of HCC, ICC and FNH and cannot replace the skills of an experienced observer.

LI-RADS-CEUS - Proposal for a Contrast-Enhanced Ultrasound Algorithm for the Diagnosis of Hepatocellular Carcinoma in High-Risk Populations.

Purpose: To develop a contrast-enhanced ultrasound algorithm (LI-RADS-CEUS = liver imaging reporting and data system with contrast-enhanced ultrasound) for the diagnosis of hepatocellular carcinoma (HCC) in patients at risk. Materials and Methods: A CEUS algorithm (LI-RADS-CEUS) was designed analogously to CT- and MRI-based LI-RADS. LI-RADS-CEUS was evaluated retrospectively in 50 patients at risk with confirmed HCC or non-HCC lesions (test group) with subsequent validation in a prospective cohort of 50 patients (validation group). Results were compared to histology, CE-CT and CE-MRI as reference standards. Results: Tumor diagnosis in the test group/validation group (n = 50/50) were 46/41 HCCs, 3/3 intrahepatic cholangiocellular carcinomas (ICCs) and 1/6 benign lesions. The diagnostic accuracy of LI-RADS-CEUS for HCC, ICC and non-HCC-non-ICC-lesions was 89 %. For the diagnosis of HCC, the diagnostic accuracy was 93.5 % (43/46 cases) in the test group and 95.1 % (39/41 cases) in the validation group. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were 94.3 %, 66.6 %, 94.3 % and 66.6 %, respectively (mean values from both cohorts). Histological findings of HCC were available in 40 versus 23 cases (in total: G1 / G2/G3: 15/35/13). Arterial hyperenhancement was seen in 68/87 (78.2 %) of HCCs. Arterial hyperenhancement with subsequent portal venous or late phase hypoenhancement was seen in 66 % of HCCs. Conclusion: LI-RADS-CEUS offers a CEUS algorithm for standardized assessment and reporting of focal liver lesions in patients at risk for HCC. Arterial hyperenhancement in CEUS is the key feature for the diagnosis of HCC in patients at risk, whereas washout is not a necessary prerequisite.

Spectrum, Applicability and Diagnostic Capacity of Contrast-Enhanced Ultrasound in Pediatric Patients and Young Adults after Intravenous Application - A Retrospective Trial.

Purpose: To investigate the spectrum, applicability and diagnostic capacity of intravenous contrast-enhanced ultrasound imaging (CEUS) in a pediatric population. Materials and Methods: From 08/2005 to 11/2015, n = 40 pediatric patients and young adults from 0 - 26 years (Ø 11.4 ±â€Š7.5) and 3.0 - 85.3 kg (Ø 40.8 ± 25.6) with n = 55 investigations received n = 79 IV applications of ultrasound contrast agent (UCA). UCA dose and side effects were documented. Scanned organs were the liver (n = 42), spleen (n = 9), kidney (n = 3), and testis (n = 1). Histology, surgery or reference imaging was compared to CEUS and clinical follow-up. Results: The UCA dose < 20 kg was 0.4 ±â€Š0.3 ml, (0.05 ±â€Š0.02 ml/kg) and > 20 kg was 1.0 ±â€Š0.4 ml (p< 0.0001) (0.02 ±â€Š0.01 ml/kg, p< 0.0001). Adverse effects occurred in 2/79 applications (2.5 %). Agreement CEUS/gold standard resulted in 32/34 investigations. For liver diagnostics (gold standard: MRI, CT, histology, serology), n = 11 malignant and n = 15 benign focal liver lesions were included. The specificity was 100 % (95 % CI: 0.77 - 1.00), the sensitivity was 82 % (95 % CI: 0.48 - 0.98), the positive predictive value was 100 % (95 % CI: 0.69 - 1.00) and the negative predictive value was 88 % (95 % CI: 0.62 - 0.98, p< 0.0001). In n = 2 reference imaging misdiagnosed and CEUS was in accordance with clinical follow-up. All splenic/renal lesions were diagnosed correctly. In n = 1 an insufficient testicular perfusion was ruled out. The observation time was 30.4 ±â€Š30.5 months. Conclusion: CEUS is a well-tolerated and diagnostically equivalent modality in pediatric care, providing fundamental advantages compared to currently approved imaging modalities for these age groups.

A Milestone: Approval of CEUS for Diagnostic Liver Imaging in Adults and Children in the USA.

The approval of microbubbles with the inert gas sulfur hexafluoride (SF6) and a palmitic acid shell (SonoVue(®), Bracco Geneva, CH) for the diagnostic imaging of liver tumors in adults and children by the FDA in the United States represents a milestone for contrast-enhanced ultrasound (CEUS).This warrants a look back at the history of the development of CEUS. The first publications based on echocardiographic observations of right ventricular contrast phenomena caused by tiny air bubbles following i. v. injection of indocyanine green appeared around 1970 1 2 3. A longer period of sporadic publications but no real progress then followed since, in contrast to X-ray methods, ultrasound works quite well without a contrast agent.It is noteworthy that the foundations for further development were primarily laid in Europe. The development and approval (1991) of the contrast agent Echovist(®) by a German contrast manufacturer for echocardiography unsuitable for passing through lungcapillaries 4 5 resulted in the first extracardiac indications, e. g. for detecting retrovesical reflux and tubal patency, in the mid-1980 s 6 7 8. The sensitivity of color Doppler was not able to compensate for the lack of an ultrasound contrast agent compared to CT with its obligatory contrast administration.Studies of SHU 508 - microbubbles of air moderately stabilized with galactose and palmitic acid - began in 1990 9 10 11 12 13 14 15 and the contrast agent was then introduced in 1995 in Germany as Levovist(®). The most important publications by Blomley, Cosgrove, Leen, and Albrecht are named here on a representative basis 16 17 18 19 20.SHU 508 along with other US contrast agents provided impressive proof of the superiority of CEUS for the diagnosis of liver metastases. However, practical application remained complicated and required skill and technical know-how because of a lack of suitable software on US units 21 22 23 24 25. The monograph regarding the use of contrast agent in the liver by Wermke and Gaßmann is impressive but unfortunately only available in German 26. In addition to being applied in the heart and the liver, CEUS was first used in transcranial applications 27 and in vessels 28, the kidneys 29, and the breast 30. Measurements at transit times were also of particular interest 31. It was difficult to convince ultrasound device manufacturers of the need to adapt US units to US contrast agents and not vice versa.The breakthrough came with low MI phase contrast inversion and the introduction of SonoVue(®) in many European countries in 2001. This more stable US contrast agent is easy to use and is becoming indispensable in diagnostic imaging of the liver 32 33 34 35 36 37 38 39 40. Studies have shown its excellent tolerability 41 and diagnostic reliability comparable to that of MDCT and MRI in the liver 42 43. Today it would be unimaginable to diagnose liver tumors without CEUS 44. This also applies to very small lesions 45 46.EFSUMB published the first CEUS guidelines in 2004 47 which have since been reissued and divided into hepatic 48 and extrahepatic applications 49. The first recommendations regarding quantitative assessment have also been published 50.The increasing scientific interest in CEUS is evident based on the greater number of PubMed hits for Echovist(®) (ca. 130), Levovist(®) (ca. 500) and SonoVue(®) (ca. 1500) as well as on the fact that publications regarding CEUS comprise almost 20 % of UiM/EJU articles in the last 10 years. The number of CEUS articles in UiM/EJU continues to be high 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75.In the clinical reality, CEUS has been able to become established alongside CT and MRI according to the saying "better is the enemy of good" 76 as the method of choice after B-mode ultrasound in the evaluation of liver tumor malignancy in Germany, where the technically challenging method is promoted. In the case of unclear CT and MRI findings, CEUS performed by an experienced examiner/clinician often provides the solution, particularly in the case of small lesions, and is the last resort before US-guided biopsy 45 46. However, there is a lack of competent CEUS examiners and Germany continues to be the world champion of X-ray examinations with no noticeable reverse trend. In almost every doctor's office and hospital, ultrasound costs are by far not fully covered, resulting in an extremely high frequency of CT use with CT being available to everyone regardless of insurance status.The USA is now in the starting position for CEUS. It will be exciting to see how the method will develop there. The FDA's decision to approve sulfur hexafluoride (Lumason(®) = SonoVue(®)) should be considered against the background of the radiation exposure caused by CT examinations and the fact that MRI using gadolinium-containing contrast agents is no longer considered noninvasive because of nephrogenic systemic fibrosis (NSF) and the accumulation of the agent in the cerebrum. An essential point of the campaign regarding the avoidance of diagnostic radiation exposure triggered in the USA by the publications of Brenner et al. 77 78 was that the agent was approved for use in the liver even for children 79 80 - still off label in Europe - without additional comprehensive studies due to the available scientific results and the very low side effects profile of Lumason(®) (= SonoVue(®)). It is admittedly unclear why other indications (except the heart which has been approved since 2014) are excluded even though the microbubbles as a pure blood pool contrast agent can be diagnostically used in the entire vascular system and bed of all organs. To our knowledge, there is no such restriction on the approval of X-ray contrast agents.Like echocardiography and emergency ultrasound, CEUS began in Europe but will probably only establish its final diagnostic value as a "reimport".This is a major opportunity to permanently define the role of Ultrasound as a highly valuable, patient-centered imaging method in the German health care system.This may prompt some of our international readers to reflect upon the role of CEUS in their own countries.

Comparison of Acoustic Radiation Force Impulse (ARFI) Elastography Measurements with the 4C1 Transducer to the 6C1HD Transducer: A Phantom and Patient Study.

Purpose: The aim of this study was to evaluate whether acoustic radiation force impulse (ARFI) elastography done with the 4C1 probe yields comparable results to the recently introduced 6C1HD probe. Materials and Methods: Measurements with the 4C1 and 6C1HD probes (Acuson S2000) were performed and compared in four different inclusions of an elasticity phantom model (QA049 CIRS) as well as in the liver of healthy individuals and patients with liver cirrhosis. Results: Measurements with the 6C1HD probe were slightly higher in all phantom inclusions (8, 14, 45, 80kPA) with a mean of 1.48 m/s (95 %-CI; 1.47 - 1.49), 2.18 m/s (95 %-CI; 2.17 - 2.19), 3.61 m/s (95 %-CI; 3.57 - 3.64) and 4.34 m/s (95 %-CI; 4.29 - 4.39) compared to the 4C1 transducer with 1.46 m/s (95 %-CI; 1.45 - 1.47), 2.15 m/s (95 %-CI; 2.14 - 2.16), 3.39 m/s (95 %-CI; 3.37 - 3.41) and 3.98 m/s (95 %-CI; 3.75 - 4.21), respectively (p = 0.04, p < 0.01, p < 0.01, p < 0.01). Cirrhotic patients (n = 40) had a higher mean shear wave speed with 3.00 m/s (95 %-CI; 2.80 - 3.21) with the 6C1HD transducer compared to 2.81 m/s (95 %-CI; 2.64 - 2.99) with the 4C1 transducer (p = 0.03). Healthy individuals (n = 20) had a mean shear wave speed of 1.12 m/s (95 %-CI; 1.06 - 1.17) with the 6C1HD probe and 1.12 m/s (95 %-CI; 1.05 - 1.19) with the 4C1 probe (p = 0.96). Conclusion: ARFI values assessed with a 6C1HD transducer are slightly higher than measurements with a 4C1 transducer in an ARFI phantom and in patients with liver cirrhosis. As the difference is small, current cut-off values keep their usefulness but should be interpreted with caution if measurements are close to the cut-off.

Pluto's interaction with its space environment: Solar wind, energetic particles, and dust.

The New Horizons spacecraft carried three instruments that measured the space environment near Pluto as it flew by on 14 July 2015. The Solar Wind Around Pluto (SWAP) instrument revealed an interaction region confined sunward of Pluto to within about 6 Pluto radii. The region's surprisingly small size is consistent with a reduced atmospheric escape rate, as well as a particularly high solar wind flux. Observations from the Pluto Energetic Particle Spectrometer Science Investigation (PEPSSI) instrument suggest that ions are accelerated and/or deflected around Pluto. In the wake of the interaction region, PEPSSI observed suprathermal particle fluxes equal to about 1/10 of the flux in the interplanetary medium and increasing with distance downstream. The Venetia Burney Student Dust Counter, which measures grains with radii larger than 1.4 micrometers, detected one candidate impact in ±5 days around New Horizons' closest approach, indicating an upper limit of <4.6 kilometers(-3) for the dust density in the Pluto system.

[Contrast-enhanced Ultrasound in Diagnostic Imaging of Muscle Injuries: Perfusion Imaging in the Early Arterial Phase]. / Kontrastmittelsonografie (CEUS) in der bildgebenden Diagnostik von Muskelverletzungen--Perfusionsdarstellung in der früharteriellen Phase.

BACKGROUND: Ultrasound is a standard procedure widely used in the diagnostic investigation of muscle injuries and widely described in the literature. Its advantages include rapid availability, cost effectiveness and the possibility to perform a real-time dynamic examination with the highest possible spatial resolution. In the diagnostic work-up of minor lesions (muscle stiffness, muscle strain), plain ultrasound has so far been inferior to MRI. The case presented by us is an example of the possibilities offered by contrast-enhanced ultrasound (CEUS) in the imaging of muscle injuries compared with plain B-mode image ultrasound and MRI imaging of the affected region. MATERIAL/METHODS: This case report is about a high-performance football player who sustained a muscle injury. He underwent an ultrasound examination (S 2000, 9L4 Probe, Siemens, Germany), which was performed simultaneously in the conventional and contrast-enhanced mode at the level of the lesion. An intravenous bolus injection of 4.8 ml of intravascular contrast agent (SonoVue(®), Bracco, Italy) was given via a cubital intravenous line. After that, the distribution of contrast agent was visualised in the early arterial phase. In addition, a plain magnetic resonance imaging scan of both thighs was performed for reference. RESULTS: On conventional ultrasound, the lesion was not clearly distinguishable from neighbouring tissue, whereas contrast-enhanced ultrasound demonstrated a well delineated, circumscribed area of impaired perfusion with hypoenhancement compared with the surrounding muscles at the clinical level of the lesion in the arterial wash-in phase (0-30 sec, after intravenous administration). The MRI scan revealed an edema signal with perifascial fluid accumulation in the corresponding site. CONCLUSION: The use of intravascular contrast agent enabled the sensitive detection of a minor injury by ultrasound for the first time. An intramuscular edema seen in the MRI scan showed a functional arterial perfusion impairment on ultrasound, which was sensitively detected in the early phase. Further examinations must be performed on muscle injuries of various degrees of severity in order to validate the application of this procedure and to standardise the examination process.

Benefit of Contrast-Enhanced Ultrasound (CEUS) in the Follow-Up Care of Patients with Colon Cancer: A Prospective Multicenter Study.

PURPOSE: According to the German guidelines on colorectal cancer, unenhanced ultrasound is recommended for follow-up. On the other hand, ultrasound and radiology societies specify the use of contrast-enhanced ultrasound for ruling out liver metastases. Studies focusing on the follow-up of cancer patients are lacking. The goal of this multicenter study initiated by the German Ultrasound Society (DEGUM) was to determine the potential benefit of contrast-enhanced ultrasound in the follow-up of patients with colon cancer. MATERIALS AND METHODS: Follow-up patients with colon cancer (UICC > IIa) were investigated. As scheduled according to the German guidelines, unenhanced ultrasound was performed followed by contrast-enhanced ultrasound. All liver lesions were recorded. In case of additional metastases detected on contrast-enhanced ultrasound, contrast-enhanced CT, MRI or biopsy was performed to confirm additional liver metastases. RESULTS: A total of 45 liver metastases were detected in 26/290 patients (= 9 %) using unenhanced ultrasound. A further 28 metastases were detected on contrast-enhanced ultrasound in these 26 patients. In 18 patients showing no liver metastases, 40 additional metastases were detected on unenhanced ultrasound. This means that 44 patients with a total of 113 liver metastases were detected on contrast-enhanced ultrasound (p = 0.0006). CONCLUSION: Contrast-enhanced ultrasound should be recommended in the follow-up of patients with colon cancer in addition to unenhanced ultrasound - the up-to-date standard.

Prospective Evaluation of Acoustic Radiation Force Impulse (ARFI) Elastography and High-Frequency B-Mode Ultrasound in Compensated Patients for the Diagnosis of Liver Fibrosis/Cirrhosis in Comparison to Mini-Laparoscopic Biopsy.

PURPOSE: Ultrasound is a well-established noninvasive test for assessing patients with liver disease. This study aims to prospectively compare ultrasound to the new technique elastography (ARFI) for the assessment of liver fibrosis/cirrhosis. MATERIALS AND METHODS: High-frequency B-mode ultrasound (liver surface/vein irregularity, liver homogeneity, spleen size), ARFI quantification, mini-laparoscopic liver evaluation including biopsy were prospectively obtained in compensated patients scheduled for liver biopsy. For the diagnosis of cirrhosis, a combined gold standard (cirrhosis at histology and/or at macroscopic liver evaluation) was used. RESULTS: Out of 157 patients, 35 patients were diagnosed cirrhotic. Ultrasound (combination of liver vein and/or surface irregularity) showed no significant difference compared to ARFI quantification for the diagnosis of significant liver fibrosis (Ishak> = 3) and cirrhosis. Diagnosis of cirrhosis had a sensitivity/specificity/PPV/NPV of 83 %(±â€Š12) / 82 %(±â€Š7) / 57 %(±â€Š14) / 94 %(±â€Š4), respectively, with ultrasound and 86 %(±â€Š12) / 81 %(±â€Š7) / 57 %(±â€Š13) / 95 %(±â€Š4), respectively, with ARFI quantification. The sensitivity/specificity/PPV/NPV for the detection of significant fibrosis were 68 %(±â€Š13) / 86 %(±â€Š7) / 71 %(±â€Š13) / 84 %(±â€Š7), respectively, for ultrasound and 70 %(±â€Š12) / 84 %(±â€Š7) / 69 %(±â€Š12) / 84 %(±â€Š7), respectively, for ARFI quantification. CONCLUSION: ARFI elastography and high-frequency B-mode ultrasound show similar and good results for the diagnosis of compensated liver cirrhosis and high-grade fibrosis. A key benefit of both methods is the high NPV suggesting them as noninvasive exclusion tests.

Quantitative perfusion analysis in pancreatic contrast enhanced ultrasound (DCE-US): a promising tool for the differentiation between autoimmune pancreatitis and pancreatic cancer.

In the work-up of focal pancreatic lesions autoimmune pancreatitis (AIP) is a rare differential diagnosis to pancreatic cancer (PC) with similar clinical constellations. The aim of our study was to compare differences between proven AIP and PC using transabdominal dynamic contrast enhanced ultrasound (DCE-US). Therefore we recorded 3-minute-clips of CEUS examinations and analyzed perfusion parameters with VueBox®-quantification software. To obtain DCE-US Parameters, Regions-of-Interest were selected within the lesions and the surrounding pancreas parenchyma, serving as reference tissue. We compared 3 patients with AIP (mean age: 58 years; lesion mean size: 40 mm) to 17 patients with PC (mean age: 68 years; lesion mean size: 35.9 mm). Significant differences between PC and parenchyma could be found in the following parameters: Peak-Enhancement (PE), Wash-in-and-Wash-out-AUC, Wash-in Perfusion-Index. PE of AIP was comparable to normal parenchyma. The relation of PE between parenchyma and lesion (ΔPE) AIP and PC was significantly different [AIP: 0.21 (±0.06); PC: 0.81 (±0.1); p<0.01]. PE of neoplastic lesions was significantly lower as AIP and normal parenchyma (p<0.01). Therefore perfusion analysis in DCE-US can help to differentiate hypovascular PC from AIP presenting nearly isovascular time intensity curves. Diagnostic accuracy of DCE-US in this setting has to be validated in future prospective studies in comparison to CT and MRI.

EFSUMB Guidelines on Interventional Ultrasound (INVUS), Part I. General Aspects (Short Version).

This is the first part of the Guidelines on Interventional Ultrasound of the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) and covers all general aspects of ultrasound-guided procedures (short version; the long version is published online).

EFSUMB Guidelines on Interventional Ultrasound (INVUS), Part I. General Aspects (long Version).

This is the first part of the Guidelines on Interventional Ultrasound of the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) and covers all general aspects of ultrasound-guided procedures (long version).

Statement of the section internal medicine of the DEGUM - ultrasound obtains pole position for clinical imaging in acute diverticulitis.

This paper reviews and interprets the role of ultrasonography in view of the recently published Guideline on diverticular disease of the Consensus conference of the German Societies of Gastroenterology (DGVS) and Visceral Surgery (DGAV) implying a new classification of diverticular disease (CDD). Qualified US is not only equipotent to qualified CT and frequently effectual for diagnosis but considers relevant legislation for radiation exposure protection. Unsurpassed resolution allows detailed resolution thereby allowing to differentiate and stratify the relevant types of diverticular disease. Subsequently, US is considered the first choice of imaging in diverticular disease. Vice versa, CT has definite indications in unclear / discrepant situations ­ or insufficient US-performance.

Incidence of bleeding in 8172 percutaneous ultrasound-guided intraabdominal diagnostic and therapeutic interventions - results of the prospective multicenter DEGUM interventional ultrasound study (PIUS study).

PURPOSE: To analyse the incidence of bleeding after percutaneous ultrasound guided diagnostic and therapeutic intraabdominal interventions in a prospective multicentre study (DEGUM percutaneous interventional ultrasound study). MATERIALS AND METHODS: Within a time period of 2 years diagnostic and therapeutic intraabdominal interventions (with the exclusion of ascites paracentesis) performed percutaneously under continuous ultrasound (US) guidance were prospectively assessed using a pseudonymized standardized web site entry form. Number and type of intervention, operator experience, patient characteristics, medication, lab data as well as technical aspects of the procedure and bleeding complications were analysed according to the interventional radiology standards. RESULTS: 8172 US-guided intraabdominal interventions (liver n = 5903; pancreas n = 501, kidney n = 434, lymph node = 272, biliary system n = 153, spleen n = 63, other abdominal organs and extra-organic targets n = 999) were analysed in 30 hospitals. The majority were diagnostic biopsies including 1780 liver parenchyma, 3400 focal liver lesions and 404 pancreatic lesions. 7525 interventions (92.1 %) were performed in hospitalized patients (mean age 62.6 years). Most operators were highly experienced in US-guided interventions (> 500 interventions prior to the study n = 5729; 70.1 %). Sedation was administered in 1131 patients (13.8 %). Needle diameter was ≥ 1 mm in 7162 punctures (87.9 %) with main focus on core needle biopsies (18 G, n = 4185). Clinically relevant bleeding complications with need of transfusion (0.4 %), surgical bleeding control (0.1 %) and radiological coiling (0.05 %) were very rare. Bleeding complications with fatal outcome occurred in four patients (0.05 %). The frequency of major bleeding complications was significantly higher in patients with an INR > 1.5 (p < 0.001) and patients taking a medication potentially interfering with platelet function or plasmatic coagulation (p < 0.0333). CONCLUSION: This prospective multicentre study confirms the broad spectrum of percutaneous US-guided intraabdominal interventions. However diagnostic liver biopsies dominate with the use of core needle biopsies (18 G). Percutaneous US-guided interventions performed by experienced sonographers are associated with a low bleeding risk. Major bleeding complications are very rare. A pre-interventional INR < 1.5 and individual medication risk assessment are recommended.

CEUS in hepatocellular carcinoma and intrahepatic cholangiocellular carcinoma in 320 patients - early or late washout matters: a subanalysis of the DEGUM multicenter trial.

PURPOSE: The aim of the study was the comparison of tumor vascularization and contrast enhancement in contrast-enhanced ultrasound (CEUS) for the characterization of hepatocellular carcinoma (HCC) and intrahepatic cholangiocellular carcinoma (ICC). We present data of the subpopulations HCC and ICC examined in the DEGUM multicenter trial for the characterization of focal liver lesions in clinical practice. MATERIALS AND METHODS: Based on the data of the DEGUM multicenter trial (1349 patients), all patients with histologically proven HCC (n = 278) and ICC (n = 42) were analyzed. The vascularity pattern and contrast enhancement pattern during the arterial, portal-venous and late phase were compared. RESULTS: An underlying liver cirrhosis was found in 214/278 patients with HCC (76.9 %) and 7/42 patients with ICC (16.7 %). In CEUS, HCC showed a global arterial hyperenhancement compared to ICC (HCC: tumor center: 60.3 %; tumor periphery: 75 %; ICC: tumor center: 16.7 %; tumor periphery: 40.5 %). ICC showed an initial contrast enhancement primarily at the tumor periphery (ICC: 85.7 % vs. HCC: 61 %) followed by an early portal-venous contrast washout in the tumor center (ICC: 85.8 % vs. HCC: 49.8 %) and tumor periphery (ICC: 66.7 % vs. HCC: 32.6 %). HCC showed a delayed contrast washout (late phase hypoenhancement: HCC: 75 % vs. ICC: 92.9 %). CONCLUSION: ICCs are rare in cirrhotic livers. CEUS can demonstrate differences in the vascularization patterns between HCC and ICC. HCC showed an arterial global hyperenhancement and delayed contrast washout in the late phase. ICCs are characterized by an arterial contrast enhancement at the tumor periphery with early contrast washout of the vascularized parts of the lesions in the portal-venous and late phase.