Assessing the performance of ultrafast vector flow imaging in the neonatal heart via multiphysics modeling and In vitro experiments

Ultrafast vector flow imaging would benefit newborn patients with congenital heart disorders, but still requires thorough validation before translation to clinical practice. This paper investigates 2-D speckle tracking (ST) of intraventricular blood flow in neonates when transmitting diverging waves at ultrafast frame rate. Computational and in vitro studies enabled us to quantify the performance and identify artifacts related to the flow and the imaging sequence. First, synthetic ultrasound images of a neonate's left ventricular flow pattern were obtained with the ultrasound simulator Field II by propagating point scatterers according to 3-D intraventricular flow fields obtained with computational fluid dynamics (CFD). Noncompounded diverging waves (opening angle of 60 degrees) were transmitted at a pulse repetition frequency of 9 kHz. ST of the B-mode data provided 2-D flow estimates at 180 Hz, which were compared with the CFD flow field. We demonstrated that the diastolic inflow jet showed a strong bias in the lateral velocity estimates at the edges of the jet, as confirmed by additional in vitro tests on a jet flow phantom. Furthermore, ST performance was highly dependent on the cardiac phase with low flows (< 5 cm/s), high spatial flow gradients, and out-of-plane flow as deteriorating factors. Despite the observed artifacts, a good overall performance of 2-D ST was obtained with a median magnitude underestimation and angular deviation of, respectively, 28% and 13.5 degrees during systole and 16% and 10.5 degrees during diastole

Covering the European union from an intergovernmental towards a supranational perspective?

This article investigates the cross-national prevalence of five news frames in quality papers' coverage of the Treaty of Lisbon (EU Constitution), Three frames were identified in earlier studies: economic consequences, conflict, and human interest. Two additional frames were identified and composed: power and nationalisation. During the seven-month period leading up to the signing of the Treaty of Lisbon (December 2007), we analysed 341 articles from four quality papers: Le Monde (France), De Volkskrant (The Netherlands), De Standaard (Dutch speaking community of Belgium), and Le Soir (French speaking community of Belgium). Our results show that although significant differences between newspapers were found in the amount of framing, overall they reflected a similar pattern in the adoption of the news frames. The economic consequences frame, followed by the power frame, appeared most prominently in all of the newspapers' coverage. However, the conflict and nationalisation frames recurred in a significantly lesser degree. These findings indicate that the meaning behind the EU Constitution as a symbol of supranational unity could have led to a shift from a domesticated, conflict oriented coverage as found in previous studies to a more unified portrayal of the EU within and between the quality papers under study

Covering the European Union: from an intergovernmental towards a supranational perspective?

This article investigates the cross-national prevalence of five news frames in quality papers' coverage of the Treaty of Lisbon (EU Constitution). Three frames were identified in earlier studies: economic consequences, conflict, and human interest. Two additional frames were identified and composed: power and nationalisation. During the seven-month period leading up to the signing of the Treaty of Lisbon (December 2007), we analysed 341 articles from four quality papers: Le Monde (France), De Volkskrant (The Netherlands), De Standaard (Dutch speaking community of Belgium), and Le Soir (French speaking community of Belgium). Our results show that although significant differences between newspapers were found in the amount of framing, overall they reflected a similar pattern in the adoption of the news frames. The economic consequences frame, followed by the power frame, appeared most prominently in all of the newspapers' coverage. However, the conflict and nationalisation frames recurred in a significantly lesser degree. These findings indicate that the meaning behind the EU Constitution as a symbol of supranational unity could have led to a shift from a domesticated, conflict oriented coverage as found in previous studies to a more unified portrayal of the EU within and between the quality papers under study.status: publishe

Pokrivanje Evropske Unije: od medvladne k nadnacionalni perspektivi?

This article investigates the cross-national prevalence of five news frames in quality papers\u27 coverage of the Treaty of Lisbon (EU Constitution). Three frames were identified in earlier studies: economic consequences, conflict, and human interest. Two additional frames were identified and composed: powerand nationalisation. During the seven-month period leading up to the signing of the Treaty of Lisbon (December 2007), we analysed 341 articles from four quality papers: Le Monde (France), De Volkskrant (The Netherlands), De Standaard (Dutch speaking community of Belgium), and Le Soir (French speaking community of Belgium). Our results show that although signifi cant differences between newspapers were found in the amount of framing, overall they reflected a similar pattern in the adoption of the news frames. The economic consequences frame, followed by the power frame, appeared most prominently in all of the newspapers\u27 coverage. However, the conflict and nationalisation frames recurred in a significantly lesser degree. These fi ndings indicate that the meaning behind the EU Constitution as a symbol of supranational unity could have led to a shift from a domesticated, conflict oriented coverage as found in previous studies to a more unified portrayal of the EU within and between the quality papers under study.Članek raziskuje meddržavno razširjenost petih novičarskih okvirov v poročanju o Lizbonski pogodbi (ustavi EU) v kakovostnih dnevnikih. Ob treh okvirih iz prejšnjih raziskav - gospodarske posledice, spori in "human interest" - sta bila ugotovljena še dva dodatna: moč in nacionalizacija. V sedemmesečnem obdobju pred podpisom Lizbonske pogodbe decembra 2007 smo analizirali 341 člankov iz štirih kakovostnih dnevnikov: Le Monde (Francija), De Volkskrant (Nizozemska), De Standaard (nizozemsko govoreča skupnost Belgija), in Le Soir (francosko govoreča skupnost v Belgiji). Naši rezultati kažejo, da čeprav so bile med časopisi pomembne razlike v obsegu okvirjanja, nasploh kažejo podoben vzorec oblikovanja okvirov novic. V vseh časopisih je najpomembnejši okvir gospodarskih posledic, ki mu sledi okvir moči. Okvira konfliktov in nacionalizacije sta se pojavljala v bistveno manjši meri. Te ugotovitve kažejo, da bi lahko pomen ustave EU kot simbola nadnacionalne enotnosti povzročil premik od podomačenega, v konflikt usmerjenega poročanja, kakršno je bilo ugotovljeno v prejšnjih raziskavah, k bolj enotni predstavitvi EU v časopisih, ki so bili vključeni v analizo

INCIDENCE AND RISK FACTORS FOR EARLY RENAL DYSFUNCTION AFTER LIVER TRANSPLANTATION

INTRODUCTION. Renal dysfunction often occurred after liver transplantation. OBJECTIVES. The aim of the study was to determine its incidence and its risk factors in a clinical series at the University Hospital of Liege, Belgium. METHODS. Orthotopic liver transplantations performed from January 2006 until Sep- tember 2012 were retrospectively reviewed (n = 187). Patients, with no renal replacement therapy (RRT) before transplantation were classified in four groups according to their highest creatinine plasma level during the first postoperative week. First group had a cre- atinine level below 12 mg/l, the second group between 12 and 20 mg/l, the third group between 20 and 35 mg/l, and the fourth above 35 mg/l. In addition, patients who needed RRT during the first week after transplantation were also classified in the fourth group. Preoperative and perioperative parameters were tested as risk factors: age, sex, body mass index (BMI), length of hospital preoperative stay, prior bacterial infection within one month, preoperative ascites, preoperative treatment with ß-blocker, converting enzyme inhibitor, or non steroidal antiinflammatory drugs, preoperative creatinine and bilirubine level, postop- erative lactate level, need for postoperative vasopressive drugs, surgical revision, mechanical ventilation for more than 24 h, postoperative peaks in bilirubine and transam- inase levels, postoperative hemoglobin level, amount of perioperative blood transfusions, type of immunosuppression. Univariate and multivariate analysis were performed using logistic ordinal regression method. RESULTS. There were 78 patients in group 1 (41.7 %), 46 in group 2 (24.6 %), 38 in group 3 (20.3 %) and 25 in group 4 (13.4 %). Eighteen patients required RRT: 13 (7 %) during the first week after transplantation (group 4), the 5 others after the first week after transplan- tation (2 in group 1 and 2, and 1 in group 3). There were 7 (3.7 %) early deaths within 28 days after transplantation. Using univariate analysis, the severity of renal dysfunction was correlated with presence of ascites and prior bacterial infection, preoperative bilirubin and creatinine level, need for surgical revision, use of vasopressor, postoperative mechanical ventilation, postoperative bilirubine, transaminase, and hemoglobin levels. The need for transfusion of each type of products also affected renal dysfunction. The ordinal logistic analysis pointed out the BMI (OR = 1.1, p = 0.004), preoperative creatinine level (OR = 11.1, p \ 0.0001), use of vasopressor (OR = 3.31, p = 0.0002), maximal postop- erative bilirubine level (OR = 1.44, p = 0.044) and minimal postoperative hemoglobin level (OR 0.059 p = 0.0005). CONCLUSIONS. More than half of liver transplanted patients experienced some degree of early renal dysfunction after transplantation. Risk factors are preoperative renal dysfunction, and mainly perioperative circulatory instability requiring the use of vasopressor and post- operative anemia

A numerical study of ultrafast vector flow imaging in the neonatal heart

Doppler flow imaging for the visualisation of neonatal intraventricular blood flow currently still has inherent limitations: beam-to-flow angle dependency, aliasing and a too low frame rate. Ultrafast imaging and vector flow estimation may resolve these limitations, yet both still require thorough validation for the pediatric cardiac setting. Hence, a computational modelling approach in the neonatal left ventricle was employed to investigate (i) diverging wave emission to acquire images at very high frame rate and (ii) subsequent speckle tracking algorithms for vector flow estimation. Single non-tilted diverging waves with an opening angle of 60° were transmitted, at a pulse repetition frequency of 9 kHz. Speckle tracking on the acquired ultrasound images provided 2D intraventricular flow estimates at a frame rate of 180 Hz for both the apical four chamber and parasternal short axis view, and this over an entire cardiac cycle. Overall, the blood flow was reasonably accurately tracked throughout the cardiac cycle, yet several imaging artefacts were observed. Zones of low flow proved very difficult to track due to clutter filtering issues, while high spatial flow gradients caused strong underestimation of systolic outflow