Abstract：
:The goal standard of contrast echocardiography is the absolute measure of myocardial perfusion using a contrast agent. Actually, several contrast agents are developed. All these agents show left ventricular opacification after intravenous injection. However, none of these agents shows an acceptable enhancement of the myocardium yet using conventional imaging techniques. The explanation of this phenomenon should be easy by measuring the acoustic characteristics of the contrast agent and then making a comparison of these characteristics with those of the myocardium. In this study we present definitions of standard acoustic parameters of ultrasound contrast agent, the backscatter coefficient Bs and the scattering-to-attenuation ratio STAR. Afterwards, considering an intravenous injection of the contrast agent, and taking into account the effects of lung filtering and cardiac pressure, the standard properties of contrast agents are determined in different sites: right ventricle (before lung passage), left ventricle (after lung passage and taking into account the pressure effect) and in the coronary system. Calculations showed that the acoustic properties are considerably influenced by these two effects: lung filtering and cardiac pressure. Comparison of these properties with the tissue properties (myocardium) is then performed. This determines the contribution of the contrast agent to the enhancement of the tissue visualization. The simulations are performed on Albunex microspheres. The results reveal that the difference between scattering of the myocardium and scattering of intravenously injected Albunex is too slight to be visible on an echographic image.
journal_name
Ultrasonicsjournal_title
Ultrasonicsauthors
Bouakaz A,de Jong N,Cachard C,Jouini Kdoi
10.1016/s0041-624x(97)00137-6subject
Has Abstractpub_date
1998-02-01 00:00:00pages
703-8issue
1-5eissn
0041-624Xissn
1874-9968pii
S0041-624X(97)00137-6journal_volume
36pub_type
杂志文章相关文献
ULTRASONICS文献大全abstract：:This paper describes fabrication and comparison of PMN-PT single crystal, PZT, and PZT-based 1-3 composite ultrasonic transducers for NDE applications. As a front matching layer between test material (Austenite stainless steel, SUS316) and piezoelectric materials, alumina ceramics was selected. The appropriate acousti...
journal_title：Ultrasonics
pub_type： 杂志文章
doi：10.1016/j.ultras.2010.04.001
更新日期：2010-08-01 00:00:00
abstract：:Traditional rotary corers and sample retrieval mechanisms for planetary drilling suffer from a variety of technical difficulties. A heavy and rigid drillstring must be assembled on-site and deployed with considerable applied preload and torque, and these mechanical loadings are difficult to react in a low gravity envi...
journal_title：Ultrasonics
pub_type： 杂志文章
doi：10.1016/j.ultras.2011.06.001
更新日期：2011-12-01 00:00:00
abstract：:Sonoelectrochemistry is undergoing a reemerging activity in the last years with an increasing number of papers appearing in a wide range of peer review journals. Applied studies which cover environmental treatments, synthesis or characterization of nanostructures, polymeric materials synthesis, analytical procedures, ...
journal_title：Ultrasonics
pub_type： 杂志文章
doi：10.1016/j.ultras.2009.09.022
更新日期：2010-02-01 00:00:00
abstract：:In acoustic and ultrasonic non-destructive testing techniques, it is sometimes beneficial to concentrate sound energy at a chosen location in space and at a specific instance in time, for example to improve the signal-to-noise ratio or activate the nonlinearity of damage features. Time Reversal (TR) techniques, taking...
journal_title：Ultrasonics
pub_type： 杂志文章
doi：10.1016/j.ultras.2016.01.010
更新日期：2016-04-01 00:00:00
abstract：:Ultrasonic reflection and transmission measurements on saturated, plane-parallel, poroelastic slabs are presented. A data processing technique is proposed to obtain poroelastic parameters from transmission measurements. A special experimental data acquisition and processing technique is applied to minimize the finite ...
journal_title：Ultrasonics
pub_type： 杂志文章
doi：10.1016/j.ultras.2008.10.006
更新日期：2009-03-01 00:00:00
abstract：:This paper describes a completely non-contact ultrasonic method of gas flow metering using air-coupled leaky Lamb waves. To show proof of principle, a simplified representation of gas flow in a duct, comprising two separated thin isotropic plates with a gas flowing between them, has been modelled and investigated expe...
journal_title：Ultrasonics
pub_type： 杂志文章
doi：10.1016/j.ultras.2018.04.008
更新日期：2018-09-01 00:00:00
abstract：:The film condensation of vapor on a cooled, downward-facing surface is a complex dynamic fluid phenomenon. This paper will describe the theoretical basis, instrumentation approach, and experimental results for a method for ultrasonic monitoring of film condensation. The ultrasound measurement system utilizes a 10 MHz ...
journal_title：Ultrasonics
pub_type： 杂志文章
doi：10.1016/s0041-624x(99)00214-0
更新日期：2000-03-01 00:00:00
abstract：:As biotechnology develops, techniques for manipulating and separating small particles such as cells and DNA are required in the life sciences. This paper investigates on-chip manipulation of microparticles in small channels by using ultrasonic vibration. The chip consists of a rectangular glass substrate with a cross-...
journal_title：Ultrasonics
pub_type： 杂志文章
doi：10.1016/j.ultras.2016.11.026
更新日期：2017-08-01 00:00:00
abstract：:An experimental ultrasonic sonar for use as a sensory aid with blind children is described. Novel signal processing techniques make the aid relatively simple to construct, yet allow many of its parameters to be changed in the field. In particular, the aid has two features, a variable range code and an automatic level...
journal_title：Ultrasonics
pub_type： 杂志文章
doi：10.1016/0041-624x(79)90010-6
更新日期：1979-01-01 00:00:00
abstract：:A novel nanocomposite-inspired in-situ broadband ultrasonic sensor previously developed, with carbon black as the nanofiller and polyvinylidene fluoride as the matrix, was networked for acousto-ultrasonic wave-based passive and active structural health monitoring (SHM). Being lightweight and small, this kind of sensor...
journal_title：Ultrasonics
pub_type： 杂志文章
doi：10.1016/j.ultras.2017.03.007
更新日期：2017-07-01 00:00:00
abstract：:This study considers the acoustic streaming in water produced by a lithotripsy pulse. Particle image velocimetry (PIV) method was employed to visualize the acoustic streaming produced by an electromagnetic shock wave generator using video images of the light scattering particles suspended in water. Visualized streamin...
journal_title：Ultrasonics
pub_type： 杂志文章
doi：10.1016/j.ultras.2005.09.004
更新日期：2006-02-01 00:00:00
abstract：:Images captured during routine clinical transcranial sonography (TCS) examination are of a low resolution, so can be confusing for diagnostic evaluations. Manual segmentation of brain structures (areas of the midbrain and substantia nigra (SN)) that are of special interest cause inter-observer and intra-observer varia...
journal_title：Ultrasonics
pub_type： 杂志文章
doi：10.1016/j.ultras.2012.04.005
更新日期：2013-01-01 00:00:00
abstract：:To understand the effect of the sound field on sonochemical luminescence, the exact sound pressure must be determined in each field. In this study it was determined by the Shlieren method, which measures the sound pressure without mixing the sound fields. We compared the efficiency of the sonochemical luminescence in ...
journal_title：Ultrasonics
pub_type： 杂志文章
doi：10.1016/s0041-624x(99)00203-6
更新日期：2000-03-01 00:00:00
abstract：:Based on the original combination of picosecond acoustics and diamond anvils cell, recent improvements to accurately measure hypersonic sound velocities of liquids and solids under extreme conditions are described. To illustrate the capability of this technique, results are given on the pressure and temperature depend...
journal_title：Ultrasonics
pub_type： 杂志文章
doi：10.1016/j.ultras.2014.04.011
更新日期：2015-02-01 00:00:00
abstract：:Most methods used to measure the thickness of thin liquid or solid surface films and coatings need access to the coated surface. In this work reflected ultrasonic pulses were used to measure a coating thickness from a solid back face. Piezoelectric transducers on the solid back face emitted ultrasound waves and receiv...
journal_title：Ultrasonics
pub_type： 杂志文章
doi：10.1016/j.ultras.2020.106291
更新日期：2021-02-01 00:00:00
abstract：:We experimentally demonstrate a very large ultrasonic band gap in a one-dimensional phononic crystal. The structure consists of periodic tungsten pillars fixed to a tailored silicon strip with a layer of epoxy. Combining local resonances and Bragg scattering, the gap ranges from 450kHz to 1250kHz, which corresponds to...
journal_title：Ultrasonics
pub_type： 杂志文章
doi：10.1016/j.ultras.2017.03.003
更新日期：2017-07-01 00:00:00
abstract：OBJECTIVES:This paper aims to apply median filters for reducing interpolation error and improving the quality of 3D images in a freehand 3D ultrasound (US) system. BACKGROUND AND MOTIVATION:Freehand 3D US imaging has been playing an important role in obtaining the entire 3D impression of tissues and organs. Reconstruc...
journal_title：Ultrasonics
pub_type： 杂志文章
doi：10.1016/j.ultras.2007.11.005
更新日期：2008-07-01 00:00:00
abstract：:The paper presents an equivalent circuit model of the polymer coated surface acoustic wave (SAW) resonators by combining coupling-of-mode (COM) description of SAW resonators and perturbation calculation of SAW propagation under polymer loading. An expression for the motional load produced by polymer coating is deduced...
journal_title：Ultrasonics
pub_type： 杂志文章
doi：10.1016/j.ultras.2010.12.006
更新日期：2011-07-01 00:00:00
abstract：:This paper deals with the influence of gas law on ultrasonic behaviour of porous media when the saturating fluid is high pressured. Previous works have demonstrated that ultrasonic transmission through a porous sample with variations of the static pressure (up to 18 bars) of the saturating fluid allows the characteriz...
journal_title：Ultrasonics
pub_type： 杂志文章
doi：10.1016/j.ultras.2010.02.003
更新日期：2010-06-01 00:00:00
abstract：:Sonic crystals are artificial structures consisting of a periodic array of acoustic scatterers embedded in a homogeneous matrix material, with a usually large impedance mismatch between the two materials. They exhibit strong sound attenuation at selective frequency bands due to the interference of multiply reflected w...
journal_title：Ultrasonics
pub_type： 杂志文章
doi：10.1016/j.ultras.2004.01.014
更新日期：2004-04-01 00:00:00
abstract：:For coupled structures surrounded by heavy fluids, it is difficult to obtain dispersion curves from an eigenvalue analysis, because the external fluid term in the coupled equation includes transcendental functions for frequency and wavenumber. Thus, in this study, the acoustic mass of the external fluid was approximat...
journal_title：Ultrasonics
pub_type： 杂志文章
doi：10.1016/j.ultras.2017.12.009
更新日期：2018-04-01 00:00:00
abstract：:This investigation deals with various new aspects of the sensitivity improvement of a pump-probe laser based acoustic method. A short laser pulse is used to excite a mechanical pulse thermo-elastically. Echoes of these mechanical pulses reaching the surface are causing a slight change of the optical reflectivity. The ...
journal_title：Ultrasonics
pub_type： 杂志文章
doi：10.1016/s0041-624x(02)00207-x
更新日期：2002-05-01 00:00:00
abstract：:The dispersion and attenuation features of the multi-physical fields coupled waves propagating in an infinite piezoelectric semiconductor and the reflection problem at a boundary which is mechanically free, electrically insulation and the dielectrically open circuit are studied in this paper. Different from the classi...
journal_title：Ultrasonics
pub_type： 杂志文章
doi：10.1016/j.ultras.2018.09.009
更新日期：2019-02-01 00:00:00
abstract：:Our objective was to investigate whether hemorrhage control can be achieved faster when high-intensity focused ultrasound (HIFU) is applied in the presence of ultrasound contrast agents (UCA) as compared to HIFU only application. Incisions (3 cm long and 0.5 cm deep) were produced in the livers of anesthetized rabbits...
journal_title：Ultrasonics
pub_type： 杂志文章
doi：10.1016/j.ultras.2006.07.018
更新日期：2006-12-01 00:00:00
abstract：:Exposure of Petunia hybrida cell suspensions to ultrasound at a frequency of 2.43 MHz in a standing wave field at an energy density of 70 Jm-3 (pressure amplitude of 0.78 MPa) decreased their mean viability to 35% after 20 min of sonication. A comparison of propagating wave and standing wave treatments at equal freque...
journal_title：Ultrasonics
pub_type： 杂志文章
doi：10.1016/s0041-624x(99)00166-3
更新日期：2000-03-01 00:00:00
abstract：:A method is proposed to measure the stress on a tightened bolt using an electromagnetic acoustic transducer (EMAT). A shear wave is generated by the EMAT, and a longitudinal wave is obtained from the reflection of the shear wave due to the mode conversion. The ray paths of the longitudinal and the shear wave are analy...
journal_title：Ultrasonics
pub_type： 杂志文章
doi：10.1016/j.ultras.2013.11.003
更新日期：2014-03-01 00:00:00
abstract：:We report on the 3-D modelling of periodic arrays of capacitive micromachined ultrasonic transducers (cMUTs) operating in fluid. Specific developments have been performed to model biperiodic transducer arrays and to take into account radiation into any stratified media at the front-side as well as the back-side of the...
journal_title：Ultrasonics
pub_type： 杂志文章
doi：10.1016/j.ultras.2004.09.006
更新日期：2005-05-01 00:00:00
abstract：:Ultrasonic insertion technique (IT) is an ultrasonic technique which involves sample immersion in a solution to determine its acoustic properties. IT is normally used to determine the acoustic properties of a medical phantom. We proposed the use of IT as an alternative technique to the common contact ultrasonic techni...
journal_title：Ultrasonics
pub_type： 杂志文章
doi：10.1016/j.ultras.2016.11.025
更新日期：2017-03-01 00:00:00
abstract：:In this paper, we investigated theoretically and experimentally the effect of the conductivity of the film located in the immediate vicinity of the free side of a piezoelectric resonator based on the PZT ceramics on its characteristics. It is shown that with increasing the conductivity of the film at first the paralle...
journal_title：Ultrasonics
pub_type： 杂志文章
doi：10.1016/j.ultras.2018.09.016
更新日期：2019-04-01 00:00:00
abstract：:It is shown that a diffuse field is not devoid of phase information, but has a correlation function equal to the Green's function. More specifically, the cross-correlation between diffuse signals in two transducers is very nearly equal to the direct response of one transducer to an impulse applied to the other. This i...
journal_title：Ultrasonics
pub_type： 杂志文章
doi：10.1016/s0041-624x(02)00156-7
更新日期：2002-05-01 00:00:00
