Search results for "Sound"
showing 10 items of 1845 documents
Transcranial magnetic resonance imaging-guided focused ultrasound treatment at 1.5 T: a retrospective study on treatment and patient-related paramete…
2020
Objective: To present a retrospective analysis of patient- and sonication-related parameters of a group of patients treated with a transcranial magnetic resonance imaging (MRI)-guided focused ultrasound (tcMRgFUS) system integrated with a 1.5-T MRI unit. Methods: The data obtained from 59 patients, who underwent the tcMRgFUS procedure from January 2015 to April 2019, were retrospectively reviewed for this study. The following data, among others, were mainly collected: skull density ratio (SDR), skull area (SA), number of available transducer elements (Tx), and estimated focal power at target (FP). For each of the four different treatment stages, we calculated the number of sonication proces…
Focal liver lesions: interobserver and intraobserver agreement of three-dimensional contrast-enhanced ultrasound-assisted volume measurements
2021
Purpose: This study was conducted to assess the interobserver and intraobserver agreement of three-dimensional contrast-enhanced ultrasound (3D-CEUS) volume calculations of focal liver lesions (FLLs).Methods: Thirty-nine patients (15 men and 24 women; mean age, 55.4 years) with 39 Flis (mean size, 3.1 +/- 1.8 cm; size range, 1 to 8 cm) prospectively underwent 3D-CEUS. Four readers calculated the volume of each lesion in an independent and blinded fashion in two separate sessions by means of a semi-automatic, commercially available proprietary software. The differences in lesion volumes (cm(3)) among sessions and readers were assessed using the Mann-Whitney U test and the Kruskal-Wallis test…
Image guidance to improve reliability and data integrity of transcranial Doppler sonography.
2012
Abstract Background Principles and accuracy of image-guided transcranial Doppler (IG TCD) sonography have been published recently. However, it remains open whether combination of image guidance and TCD offers an additional clinical advantage. This study scores the accuracy of conventional TCD examinations and investigates the potential improvement of TCD data integrity and reliability regarding the additional use of IG. Methods Conventional TCD was performed by a group of experienced investigators, who were blinded to images of a navigation system tracking the Doppler probe, whereas an independent observer documented the TCD findings, acquired by the investigators, due to saving spatial dat…
Removal of Viscoelastic Substances
2000
All viscoelastics should be completely removed from the eye to reduce the likelihood of increased intraocular pressure. Should OVD retention behind the IOL occur, an unstable refraction could result. Residual high molecular viscous substance is transported away through the trabecular meshwork, with delay, possibly resulting in a protracted postoperative IOP increase. To aspirate viscoelastics various techniques as well as instruments with different aspiration/irrigation adjustments have been proposed, a few of which will be described here. Viscoelastic removal involving the simultaneous irrigation and aspiration through a single cannula (Nevyas, 1987) or two separate cannulas (Brauweiler, 1…
Characterization of impervious layers using scale models and an inverse method
2009
We describe a novel procedure that uses an inverse method to determine unknown parameters for impervious layers used in multilayer structures. The proposed model of the multilayer structure is limited to an ideal double plate separated by an unbonded, fibrous, sound-absorbing material. Experimental data were obtained by nearfield acoustic holography for the calculation of the transmission loss of various multilayer structures mounted in a window in a wooden box designed specifically for this purpose. We used the Trochidis and Kalaroutis forecast model of acoustic insulation for multilayer structures, which is based on a spatial Fourier transform. The experimental pressure and velocity data …
Does transvaginal color Doppler sonography differentiate between developing and involuting ectopic pregnancies?
1995
The objective of this study was to assess the addition of transvaginal color Doppler imaging to transvaginal ultrasonography and beta-human chorionic gonadotropin values to differentiate between developin and involuting ectopic pregnancies. Forty surgically confirmed ectopic pregnancies were classified into developing or involuting according to histopathologic findings. Results were compared retrospectively with the plasma beta-human chorionic gonadotropin values as well as the resistive index and pulsatility index obtained in corpora lutea and peritrophoblastic flow in serial examinations. Student's t-test was used for comparison of means. Logistic regression analysis was applied to predic…
Volumetric and Ultrasonic Studies of 1-Ethyl-3-methylimidazolium Trifluoromethanesulfonate Ionic Liquid with Methanol, Ethanol, 1-Propanol, and Water…
2007
The speed of sound and density of mixtures of 1-ethyl-3-methylimidazolium trifluoromethanesulfonate ([emim][triflate]) with methanol, ethanol, 1-propanol, and water, as well as of the pure components have been experimentally measured over the whole range of compositions at T = (278.15 to 338.15) K and atmospheric pressure. From these experimental data, the excess molar volume, excess isentropic compressibility, and excess speed of sound have been calculated and fitted to an extended version of the Redlich−Kister equation, which takes into account the dependence on composition and temperature simultaneously. The Prigogine−Flory−Patterson theory has also been used to explain the behavior of t…
Density, Speed of Sound, and Refractive Index of 1-Ethyl-3-methylimidazolium Trifluoromethanesulfonate with Acetone, Methyl Acetate, and Ethyl Acetat…
2009
Densities, speeds of sound, and refractive indices of the binary mixtures of 1-ethyl-3-methylimidazolium trifluoromethanesulfonate ([emim][triflate]) with acetone, methyl acetate, and ethyl acetate were experimentally measured over the whole range of compositions at T = (278.15 to 328.15) K and a pressure of 0.1 MPa. From these experimental data, excess molar volumes, excess isentropic compressibilities, molar refractions, and deviations in refractive indices have been calculated and fitted to an extended version of the Redlich−Kister equation, which takes into account the dependence on composition and temperature simultaneously. The Prigogine−Flory−Patterson theory has been used to specula…
Introduction : formes de l'iconicité
2014
International audience; L'emploi du terme "eikon" pour désigner une forme linguistique fonctionnant comme une image est aussi ancien que la tradition linguistico-grammaticale de l'Occident. Il figure en effet pour la première fois dans le Cratyle de Platon (439a), point de départ de cette tradition. Pour Platon, qui ne distingue pas encore entre signifiant et signifié, il est raisonnable d'affirmer que le nom, dans son ensemble, et jusqu'à ses éléments phonologiques, opère comme une image de la chose signifiée, ce qui constitue du reste une bonne raison pour s'en méfier et préférer la connaissance directe des choses à celle de leurs représentations. La reprise du terme "icon" dans la pensée…
«Ad serviendum in cantari di musica et sunari di tasto»: contesti e modalità di formazione musicale a Palermo in età moderna
2022
Il saggio discute alcune delle modalità di formazione musicale diffuse a Palermo nel periodo del viceregno spagnolo, dai primi anni del Cinquecento sino alla prima metà del Settecento. Considerando l'arco temporale, si propone una panoramica generale delle occasioni, dei contesti e dei luoghi nei quali a Palermo si potevano apprendere nozioni di natura musicale. Infatti, anche in seguito alla fondazione nel 1617 del Conservatorio per i “figlioli dispersi”, dove circa un secolo dopo veniva introdotto ufficialmente l’insegnamento della musica, molti altri sistemi continuarono a esercitare la loro attività di formazione, conservando un’innegabile vitalità. È a queste realtà che si rivolgerà la…