Search results for "DOPPLER"
showing 10 items of 637 documents
Transesophageal contrast echocardiography is not always the gold standard method in the identification of a patent foramen ovale: A clinical case
2015
In the embryo, Eustachian valve is a crescent-shaped membrane extending from the lower margin of the inferior vena cava and the ostium of the coronary sinus into the right atrium toward fossa ovalis and tricuspid valve. At birth, after the functional closure of the foramen ovale, the Eustachian valve loses its function, reducing to an embryo remnant. According to growing evidence, a persistent Eustachian valve is a frequent finding in patients with a patent foramen ovale (PFO). By directing the blood from the inferior cava to the interatrial septum, it may prevent the spontaneous closure of PFO after birth and indirectly predispose to paradoxical embolism. Transesophageal contrast enhanced …
The progression rate of aortic stenosis: key to tailoring the management and potential target for treatment
2021
: Aortic stenosis is the most frequent valvular disease to require intervention in the western world and has always been featured as a progressive disease. The rate of progression can be assessed by carefully performed Doppler echocardiography and can vary greatly between individuals with a profound impact on prognosis. Unfortunately, the determinants of disease progression had been insufficiently studied and remain challenging to define, particularly in the outpatient setting. Multiple factors have been proposed and tested, but at present, there are no proven therapies to slow the course of the stenotic process. Heart valve clinics may be particularly important to define the progression ra…
Tratamiento del mioma con acetato de ulipristal: control evolutivo con ecografía/angiografía tridimensional
2020
A pesar de la alta prevalencia y el enorme impacto que tienen los miomas uterinos en la calidad de vida, el sistema de salud y la economía, no existe un tratamiento médico efectivo para eliminar los miomas. Esto se debe en parte al hecho de que se sabe muy poco sobre su fisiopatología; Desde hace unos años tenemos un tratamiento médico para controlar la sintomatología y reducir el tamaño de los miomas. En el estudio de esta tesis doctoral hemos estudiado muchas características ecográficas, evaluando todos los ítems que recomienda en la declaración MUSA, en los miomas bajo tratamiento con acetato de ulipristal, con la intención de identificar qué parámetro ecográfico nos puede ayudar a saber…
Timing an Accreting Millisecond Pulsar: Measuring the Accretion Torque in IGR J00291+5934
2006
We performed a timing analysis of the fastest accreting millisecond pulsar IGR J00291+5934 using RXTE data taken during the outburst of December 2004. We corrected the arrival times of all the events for the orbital (Doppler) effects and performed a timing analysis of the resulting phase delays. In this way we have the possibility to study, for the first time in this class of sources, the spin-up of a millisecond pulsar as a consequence of accretion torques during the X-ray outburst. The accretion torque gives us for the first time an independent estimate of the mass accretion rate onto the neutron star, which can be compared with the observed X-ray luminosity. We also report a revised valu…
INFLUENZA DELL’ATEROSCLEROSI CAROTIDEA PRECLINICA SUGLI EVENTI CEREBRO- E CARDIOVASCOLARI IN 5 ANNI DI FOLLOW-UP. INFLUENCE OF PRECLINICAL CAROTID AT…
2009
Introduzione: numerosi studi hanno utilizzato la valutazione dello spessore intima-media carotideo (IMT) come marker di aterosclerosi (ATS) preclinica ed è stato ampiamente dimostrato che l’IMT correla con la presenza di ATS coronarica ed è predittivo di eventi sia cardio- che cerebrovascolari. Scopo dello studio: valutare se in soggetti asintomatici la presenza di ATS carotidea preclinica, ispessimento medio intimale carotideo (IMT) e placca carotidea asintomatica (PCA), aggiunga ulteriori informazioni nella stratificazione del rischio permettendo di individuare soggetti che potrebbero beneficiare di un trattamento più aggressivo, anche farmacologico, dei fattori di rischio presenti. Mater…
El Doppler de la arteria vertebral como alternativa al Doppler de la arteria cerebral media en el diagnóstico de la restricción del crecimiento fetal
2017
En el feto, la irrigación cerebral proviene fundamentalmente de dos ramas, la arteria vertebral y la arteria carótida interna, que formarán posteriormente el polígono de Willis. Por una parte, la arteria vertebral que es, generalmente, la primera rama y la de mayor tamaño de la arteria subclavia. Ésta irriga toda la parte posterior del cerebro. Por otro lado, la arteria carótida interna irriga la parte anterior del cerebro y es de mayor calibre que la arteria carótida externa, ambas procedentes de la arteria carótida común. La arteria carótida interna y su mayor rama, la arteria cerebral media (ACM), ha sido ampliamente estudiada debido a que está implicada en el mecanismo de “brain-sparing…
[Detection of extra-articular soft-tissue involvement in rheumatoid arthritis: value of color-coded Doppler sonography]
2002
Ultrasound bioeffects in rats: quantification of cellular damage in the fetal liver after pulsed Doppler imaging
2011
Objective To determine whether pulsed Doppler examination of the ductus venosus in rat fetuses could damage exposed tissue. Methods On gestational day 18, the livers of a mean of approximately five fetuses per mother (n = 5.14, SD = 1.6), in a cohort of 35 pregnant female rats, were exposed individually to pulsed Doppler and these were considered the 'exposed group'. The remaining fetuses in each pregnant rat (n = 5.16, SD = 2.1) formed the 'control group'. We tested for 600, 300, 60, 20, 15, 10 and 3 s of exposure of the fetal ductus venosus and the damage was evaluated measuring a cell death index of apoptotic activity at 7 h post-exposure (n = 16). In addition, subgroups of mothers were …
Experimental Observation of a Large Low-Frequency Band Gap in a Polymer Waveguide
2018
The quest for large and low-frequency band gaps is one of the principal objectives pursued in a number of engineering applications, ranging from noise absorption to vibration control, and to seismic wave abatement. For this purpose, a plethora of complex architectures (including multiphase materials) and multiphysics approaches have been proposed in the past, often involving difficulties in their practical realization. To address the issue of proposing a material design that enables large band gaps using a simple configuration, in this study we propose an easy-to-manufacture design able to open large, low-frequency complete Lamb band gaps exploiting a suitable arrangement of masses and stif…
H1-antihistamines suppress wheal-and-flare reaction and skin blood perfusion measured by Laser Dopppler flowmetry: randomized, double-blind, placebo-…
2010
H1-antihistamines suppress wheal-and-flare reaction and skin blood perfusion measured by Laser Dopppler flowmetry: randomized, double-blind, placebo-controlled, crossover design study The aim of our study was to compare the influence of pre-treatment with H1-antihistamines (levocetirizine, desloratadine, clemastine, quifenadine, and sequifenadine) and a placebo on the histamine-induced weal and flare reaction, increase of skin blood perfusion and sedation. Thirty healthy volunteers were enrolled in the study. The study design was a prospective, randomised, double-blind, placebo-controlled, crossover, balanced clinical trial. Volunteers in randomised and double-blind order were treated with …