A Case for Electron-Astrophysics.

The smallest characteristic scales, at which electron dynamics determines the plasma behaviour, are the next frontier in space and astrophysical plasma research. The analysis of astrophysical processes at these scales lies at the heart of the research theme of electron-astrophysics. Electron scales are the ultimate bottleneck for dissipation of plasma turbulence, which is a fundamental process not understood in the electron-kinetic regime. In addition, plasma electrons often play an important role for the spatial transfer of thermal energy due to the high heat flux associated with their velocity distribution. The regulation of this electron heat flux is likewise not understood. By focussing on these and other fundamental electron processes, the research theme of electron-astrophysics links outstanding science questions of great importance to the fields of space physics, astrophysics, and laboratory plasma physics. In this White Paper, submitted to ESA in response to the Voyage 2050 call, we review a selection of these outstanding questions, discuss their importance, and present a roadmap for answering them through novel space-mission concepts.

In Situ Observation of Hall Magnetohydrodynamic Cascade in Space Plasma.

We present estimates of the turbulent energy-cascade rate derived from a Hall-magnetohydrodynamic (MHD) third-order law. We compute the contribution from the Hall term and the MHD term to the energy flux. Magnetospheric Multiscale (MMS) data accumulated in the magnetosheath and the solar wind are compared with previously established simulation results. Consistent with the simulations, we find that at large (MHD) scales, the MMS observations exhibit a clear inertial range dominated by the MHD flux. In the subion range, the cascade continues at a diminished level via the Hall term, and the change becomes more pronounced as the plasma beta increases. Additionally, the MHD contribution to interscale energy transfer remains important at smaller scales than previously thought. Possible reasons are offered for this unanticipated result.

Contrast-enhanced sonography in the diagnosis of hepatic hemangiomas: atypical appearance due to the washout of microbubbles.

Contrast-enhanced sonography (CEUS) examination permits identification of hemangioma of the liver in most cases. This method is particularly useful when the ultrasound pattern is atypical on standard grayscale examination. CEUS appearances suggestive of hemangioma are peripheral globular enhancement, progression of enhancement toward the center of the nodule, and persistence of enhancement in the late phase. We present seven cases of hemangioma, which were atypical on CEUS examination due to washout during the portal and late phases, resulting in a hypoenhanced appearance compared with the adjacent liver parenchyma.

Strain elastography in Crohn's disease: the role of visual observation and semiquantitative parameters.

Strain elastography is a recently developed ultrasound method that seems to contribute to the diagnosis and monitoring of inflammatory bowel diseases. This pictorial essay aims to present the feasibility of strain elastography in clinical practice by comparing visual observation and semiquantitative parameters with endoscopic or radiological images in some common cases of Crohn's disease. In our opinion, strain elastography with visual observation is easily performed in connection with B-mode ultrasound and color Doppler imaging and may provide relevant information. Strain elastography with the elaboration of semiquantitative parameters is not as immediate as the visual observation method, but it seems to provide more objective data and seems more appropriate for monitoring the evolution of the disease. However, for the elastographic method to extensively contribute in inflammatory bowel diseases, standardization and further studies are required to confirm the promising results already reported in the literature.

Multiparametric ultrasound in the diagnosis and monitoring of ischemic colitis: description of a case of ischemic colitis of the right colon and revision of the literature.

The aim of this paper is to describe the usefulness of multiparametric US in the diagnosis and subsequent follow-up of a case of right-side ischemic colitis and to present a review of the data reported in the literature. Ischemic colitis is frequently diagnosed in the field of gastroenterology. Diagnosis is usually based on the outcome of endoscopy and histological examination, and in case of right-side ischemic colitis also on the results of contrast-enhanced CT. In the described case, multiparametric US indicated the diagnosis including a prognostic judgment, and during follow-up US-monitored patency of the stents positioned under angiographic guidance. One of the available US techniques, CEUS, seems to have a special role in the detection of residual vascularization of the gastrointestinal tract affected by ischemia. However, before introducing this method into daily clinical practice, further studies are required to confirm its diagnostic accuracy.

Normal Values of the Mitral-Aortic Intervalvular Fibrosa Thickness: A Multimodality Study.

BACKGROUND: The avascular region of the fibrous body between the mitral and aortic valves, named mitral-aortic intervalvular fibrosa (MAIVF), is often involved in the periaortic diffusion of infective endocarditis (IE), resulting in abscess or pseudoaneurysm formation. The early recognition of these life-threatening complications is of crucial importance, as urgent surgical correction is necessary. In the first stages of the abscess formation, the only sign is an increased thickness of the MAIVF. To the best of our knowledge, normal transesophageal echocardiography (TEE) examination reference values for MAIVF thickness has not yet been established. The aim of the study was to define the normal ranges of MAIVF thickness in a population of healthy adults who underwent a TEE examination. MATERIALS AND METHODS: A population of consecutive adult patients who underwent a TEE examination was enrolled in the study. Measurement was performed in short-axis (SAX) and long-axis (LAX) views. Mean-2 standard deviations (mean-2SDs) and 5%, 10%, 90%, and 95% confidence intervals were evaluated. A comparison with MAIVF thickness in patients affected by aortic IE complicated by abscess formation was performed, and receiver operating characteristic (ROC) curves were constructed to achieve the optimal cutoff value of normality. RESULTS: A total of 477 consecutive Caucasian adult patients were enrolled (mean age: 69 years, range: 27-93 years). Mean-2SD MAIVF measurement in SAX view was 0.325 cm (95% confidence interval [CI]: 0.319-0.330 cm) and in LAX view was 0.340 cm (95% CI: 0.334-0.346 cm). Computed tomography-MAIVF mean measurement (±2SD) was 0.237 cm (95% CI: 0.110-0.340 cm). ROC curves showed that a cutoff SAX value measurement of 0.552 (area under the curve [AUC]: 95.2%) had a sensibility of 88.2% and a specificity of 92.4%; a LAX measurement value of 0.623 (AUC: 93.3%) had a sensibility of 82.7% and a specificity of 85.7%. The multivariate analysis showed no significant correlation between MAIVF thickness, age, and sex. CONCLUSION: In healthy patients, MAIVF thickness should not exceed 0.600 cm. Above these values, the suspicion of a periaortic abscess formation should be raised. MAIVF increased thickness may be an early sign of perivalvular diffusion requiring an urgent endocarditis team evaluation.

Contrast-enhanced sonography of a hepatocellular carcinoma undergoing spontaneous necrosis.

Spontaneous necrosis of hepatocellular carcinoma (HCC) is rare. We report the case of a 72-year-old woman with an HCC nodule that underwent necrosis after sonographically guided needle biopsy. Baseline sonographic examination revealed only a nonspecific change in the echogenicity of the lesion. Subsequent necrosis was suggested on contrast-enhanced sonographic examination and was confirmed on spiral CT.

Multimodality Imaging and Clinical Significance of Congenital Ventricular Outpouchings: Recesses, Diverticula, Aneurysms, Clefts, and Crypts.

The high spatial resolution of cardiac computed tomography (CT) and cardiac magnetic resonance (CMR) permit the diagnosis of congenital ventricular outpouchings (CVOs), including congenital ventricular diverticula (CVD), congenital ventricular aneurysms (CVA), clefts, and crypts. A unique classification has not been established, and these terms are used interchangeably with confounding terminology. Moreover, their significance is not univocal. A research was performed using PubMed on six subjects: (1) congenital left ventricular outpouchings; (2) congenital ventricular diverticulum; (3) congenital ventricular aneurysm; (4) ventricular clefts; (5) ventricular crypts; and (6) ventricular crevices. Usually, CVOs are small with a preserved contraction and in asymptomatic patients, the clinical relevance may be minimal, although electrocardiographic anomalies are often present. CVA and diverticula may carry an embolic risk and cases of arrhythmia and rupture are described. In the presence of clefts, or crypts a cardiomyopathy should be excluded. A simple classification can be proposed: CVD extend beyond the myocardial wall and fibrous type may be termed CVA, acquired forms should be kept distinct. Clefts, or crypts, are small recesses extending for more than 50% of the ventricular wall but not beyond its margin. The presence of fibrosis may be evaluated by CMR. A multicenter prospective registry would be helpful to investigate potential clinical implications and to exclude dubious forms of hypertrophic cardiomyopathy or ventricular noncompaction. In conclusion, CVOs have been described with different terminologies and classifications. Their significance needs to be interpreted in the clinical setting and with the help of a multimodality imaging, particularly of CMR.

Contrast-enhanced ultrasonography in clinical practice in Crohn's disease: feasibility of destruction/replenishment method and software analysis.

The aim of this Pictorial Essay is to evaluate the feasibility in the clinical practice of CEUS destruction/replenishment method and time intensity curve (TIC) analysis using the available software in patients with Crohn's disease. The ultrasound (US) procedure using contrast agent is briefly described, elaboration and analysis of the US sequences are explained in detail, and some advantages and disadvantages of the method are highlighted. The Authors suggest that the destruction/replenishment method is useful and time-saving in Crohn's disease if multiple measurements are required on intestinal portions adjacent to each other or in different locations.

Real-time elastography in Crohn's disease: feasibility in daily clinical practice.

Ultrasound (US) is the first-line investigation in patients with abdominal symptoms and it has a role in the diagnosis and monitoring of inflammatory bowel diseases. Strain elastography (SE) is a US method for estimating tissue elasticity. This method is still not routinely used in clinical practice, although it is suggested by the EFSUMB Guidelines for the characterization of intestinal stenosis in Crohn's disease. The purpose of this Pictorial Essay is to confirm the feasibility of elastography in Crohn's disease in clinical practice by comparing elastography images with corresponding endoscopic or radiological images. At present, diagnostic accuracy of SE is reported in the literature only in connection with detection of bowel wall fibrosis in advanced cases of Crohn's disease. However, in our opinion, SE can add useful diagnostic information to grayscale and color Doppler US by providing a more accurate characterization of the bowel wall in the various manifestations of Crohn's disease.

Multimodality Imaging of a Silent Cardiac Hemangioma.

A 74-year-old man underwent echocardiographic exam for hypertension screening. A fixed plurilobulated mass originating from the right ventricular lateral wall and occupying half of the cavity was incidentally diagnosed. On cardiac magnetic resonance (CMR) it appeared homogeneous, intermediate-to-high signal on T1-weighted, and diffusely hyperintense on T2-weighted images. First pass enhancement was late and heterogeneous and no late gadolinium enhancement was present. Computed tomography (CT) showed no extracardiac infiltration, the feeding artery was a branch of therightcoronary artery. The tumor was excised and histological examination demonstrated a hemangioma of the cavernous type. The postoperative course was uneventful. From 1998 to 2014, four cardiac hemangiomas have been diagnosed in our Department, accounting for 8.7% of all primary cardiac tumors and for 9.5% of all benign forms; estimated population prevalence was 0.11/100.000 inhabitants/year. The hemodynamic consequences of unoperated cardiac hemangiomas cannot be predicted and therefore, resection is recommended.

[The meaning and usefulness of spiral CT for radiolucent ureteric stones diagnosis: our experience]. / The meaning and usefulness of spiral TC for radiolucent ureteric stones diagnostic: our experience.

The aim of this work was to report some case histories on the usefulness of spiral TC, used for several years both to diagnose renal colic and urinary lithiasis and to study radio lucent stones that are often difficult to be detected with traditional radiology. 13 patients, aged between 31 and 76 (average age: 54.2), were therefore examined. Eight of them had a ureteral colic when examined, while five patients had shown symptoms some days before being hospitalised in our ward. In all cases, ultrasonography showed a significant hydronephrosis, while direct radiography of the urinary tract could not detect any images that could be associated with radio-opaque lithiasis. All patients therefore underwent an abdominal spiral TC with no contrast medium within 24 hours after hospitalisation. The confrontation between the results obtained by ultrasonography and those obtained by spiral TC, showed the usefulness of the former method to detect stones located in the proximal ureter or in its intramural tract, while the latter could detect the lithiasis of the proximal ureter in 3 cases (23%), of the mid ureter in 2 cases (15.3%), and of the distal ureter in 8 cases (61%). The stones had, approximately, a 5 mm diameter in 5 cases. In 6 cases the diameter was between 6 and 10 mm, and more than 1 cm in 2 cases. Both methods proved to be equally accurate in the assessment of the hydronephrosis degree and of the thickness of the renal parenchyma. The therapy was medical in 2 cases and open surgery in 3 cases, while 8 patients were treated with ureterolitholapaxy with a ballistic searcher. The usefulness of TC in the study of urolithiasis nowadays is supported by a large literature which clearly supplies with documentary evidence the high sensitivity and specificity of such a method in diagnosing the presence of urolithiasis in general and above all of ureteric stones. Such a method not only makes an accurate evaluation of the stones location possible, but it can also assess the calculi dimensions and the indirect signs of the functionality of the kidney affected, without having to use the contrast medium. This method needs very limited execution times and allows a diagnostic of possible collateral pathologies. The main disadvantage of spiral TC, if compared to conventional radiology, is that the patient is exposed to a larger quantity of ionizing radiations, although such an inconvenience will be overcome by the new and more technologically advanced machines. According to our experience, though based on a limited number of cases, spiral TC allowed us to get a quick diagnosis of radio-lucent lithiasis, to see the seat and dimensions of the calculi and finally to chose the most effective treatment. We can therefore think of a diagnostic protocol, for ureteral colics with hydronephrosis or complicated by hyperpyrexia or sepsis, with spiral TC in order to have a quick diagnosis and start the most effective therapy in case an ultrasonographic research should not result diriment.