Abstract:
:Although, high resolution, real-time ultrasonic (US) imaging is routinely available, image interpretation is based on grey-level and texture and quantitative evaluation is limited. Other potentially useful diagnostic information from US echoes may include modifications in tissue acoustic parameters (speed, attenuation and backscattering) resulting from disease development. Changes in acoustical parameters can be detected using time-of-flight and spectral analysis techniques. The objective of this study is to explore the potential of three parameters together (attenuation coefficient, US speed and integrated backscatter coefficient-IBC) to discriminate healthy and fibrosis subgroups in liver tissue. Echoes from 21 fresh in vitro samples of human liver and from a plane reflector were obtained using a 20-MHz central frequency transducer (6-30 MHz bandpass). The scan plane was parallel to the reflector placed beneath the liver. A 30 x 20 matrix of A-scans was obtained, with a 200-microm step. The samples were classified according to the Metavir scale in five different degrees of fibrosis. US speed, attenuation and IBC were estimated from standard methods described in the literature. Statistical tests were applied to the results of each parameter individually and indicated that it was not possible to identify all the fibrosis groups. Then a discriminant analysis was performed for the three parameters together resulting in a reasonable separation of fibrotic groups. Although the number of tissue samples is limited, this study opens the possibility of enhancing the discriminant capability of ultrasonic parameters of liver tissue disease when they are combined together.
journal_name
Ultrasonicsjournal_title
Ultrasonicsauthors
Meziri M,Pereira WC,Abdelwahab A,Degott C,Laugier Pdoi
10.1016/j.ultras.2004.09.002subject
Has Abstractpub_date
2005-03-01 00:00:00pages
305-13issue
5eissn
0041-624Xissn
1874-9968pii
S0041-624X(04)00263-Xjournal_volume
43pub_type
杂志文章相关文献
ULTRASONICS文献大全abstract::The wear behaviors of grinding wheel have significant influence on the work-surface topography. However, a comprehensive and quantitative method is lacking for evaluating the wear conditions of grinding wheel. In this paper, a fractal analysis method is used to investigate the wear behavior of resin-bonded diamond whe...
journal_title:Ultrasonics
pub_type: 杂志文章
doi:10.1016/j.ultras.2017.10.012
更新日期:2018-03-01 00:00:00
abstract::A laser-based technique for the contact-free generation and detection of strongly nonlinear surface acoustic wave (SAW) pulses with amplitudes limited by the materials strength has been developed. The effects of nonlinear propagation of short elastic surface pulses with finite strength in isotropic solids, such as fus...
journal_title:Ultrasonics
pub_type: 杂志文章
doi:10.1016/j.ultras.2008.06.002
更新日期:2008-11-01 00:00:00
abstract::In this paper, a new topological structure for the Langevin-type ultrasonic transducer is proposed and investigated. The two cylindrical terminal blocks are conically shaped with four supporting plates each, and two cooling fins are disposed at the bottom of terminal blocks, adjacent to the piezoelectric rings. Experi...
journal_title:Ultrasonics
pub_type: 杂志文章
doi:10.1016/j.ultras.2016.11.008
更新日期:2017-03-01 00:00:00
abstract::Investigation was carried out to study the effects of maximum aggregate size (MAS) (12.5mm, 19.0mm, 25.0mm, 37.5mm, and 50.0mm) on ultrasonic pulse velocity (UPV) of concrete. For investigation, first class bricks were collected and broken to make coarse aggregate. The aggregates were tested for specific gravity, abso...
journal_title:Ultrasonics
pub_type: 杂志文章
doi:10.1016/j.ultras.2016.04.006
更新日期:2016-07-01 00:00:00
abstract::Ultrasound wave propagation in nanofluids and its rheological behavior has been studied as a function of solid volume fraction, temperature and magnetic field for magnetic nanofluids synthesized in kerosene and transformer oil. Ultrasonic velocity decreases while viscosity increases with increasing volume fraction. Th...
journal_title:Ultrasonics
pub_type: 杂志文章
doi:10.1016/j.ultras.2014.08.017
更新日期:2015-01-01 00:00:00
abstract::The conventional acoustic nonlinear technique to evaluate the contact acoustic nonlinearity (CAN) at solid-solid contact interfaces (e.g., closed cracks), which uses the through-transmission of normally incident bulk waves, is limited in that access to both the inner and outer surfaces of structures for attaching puls...
journal_title:Ultrasonics
pub_type: 杂志文章
doi:10.1016/j.ultras.2012.02.008
更新日期:2012-08-01 00:00:00
abstract::When casting ceramic items in potteries, liquid 'slip' is passed from a settling tank, through overhead pipelines, before being pumped manually into the moulds. It is not uncommon for bubbles to be introduced into the slip as it passes through the complex piping network, and indeed the presence of bubbles is a major s...
journal_title:Ultrasonics
pub_type: 杂志文章
doi:10.1016/j.ultras.2009.07.008
更新日期:2010-01-01 00:00:00
abstract::The wave propagation of an infinite functionally graded plate in thermal environments is studied using the higher-order shear deformation plate theory. The thermal effects and temperature-dependent material properties are both taken into account. The temperature field considered is assumed to be a uniform distribution...
journal_title:Ultrasonics
pub_type: 杂志文章
doi:10.1016/j.ultras.2011.05.009
更新日期:2011-12-01 00:00:00
abstract::The ultrasound-induced harmonic microbubble response spectrum is known to shift to lower frequencies with increasing tissue attenuation. We hypothesized that this shift could be reproducibly detected in received broadband radiofrequency spectra. We used an automatic Gaussian curve-fitting technique to measure the mean...
journal_title:Ultrasonics
pub_type: 杂志文章
doi:10.1016/s0041-624x(02)00397-9
更新日期:2003-03-01 00:00:00
abstract::The objective of this paper is to develop a nondestructive method for estimating the fracture toughness (K(IC)) of CrMoV steels used as the rotor material of steam turbines in power plants. To achieve this objective, a number of CrMoV steel samples were heat-treated, and the fracture appearance transition temperature ...
journal_title:Ultrasonics
pub_type: 杂志文章
doi:10.1016/s0041-624x(03)00154-9
更新日期:2003-09-01 00:00:00
abstract::Diversity of acoustic streaming field in a 2D rectangular chamber with a traveling wave and using water as the acoustic medium is numerically investigated by the finite element method. It is found that the working frequency, the vibration excitation source length, and the distance and phase difference between two sepa...
journal_title:Ultrasonics
pub_type: 杂志文章
doi:10.1016/j.ultras.2014.11.015
更新日期:2015-04-01 00:00:00
abstract::Guided modes propagation in intact, fractured and healing long bone has drawn significant research interests. However, mode quantifications for the direct comparison are still necessary to address. The aim of the study is to analyze the mode interaction with a notch-fracture in the long bone and find quantitative ultr...
journal_title:Ultrasonics
pub_type: 杂志文章
doi:10.1016/j.ultras.2013.09.015
更新日期:2014-07-01 00:00:00
abstract::An eight-channel ultrasonic detecting device for microbiological quality evaluation of packed liquid foods is presented in this paper. This device makes possible a non-invasive detection of the microbial growth in liquid foods with no need to open the carton-based packages where they are contained. Thermal and humidit...
journal_title:Ultrasonics
pub_type: 杂志文章
doi:10.1016/j.ultras.2006.07.011
更新日期:2006-12-01 00:00:00
abstract::A circular cylindrical piezoelectric transducer with radial polarization is proposed. The axial vibration characteristics of the transducer are studied by three different methods: analytical calculation, FEM simulation and experiment. The symmetric and asymmetric excitation conditions are discussed in the Haskins and ...
journal_title:Ultrasonics
pub_type: 杂志文章
doi:10.1016/j.ultras.2009.09.008
更新日期:2010-03-01 00:00:00
abstract::Surface acoustic wave (SAW) waveguide resonator is formed by a ring-shaped strip of copper 10 microm wide and approximately 130 microm in diameter embedded into a 0.8 microm thick layer of silica on a silicon wafer. SAWs are excited at one side of the copper ring by a short laser pulse focused into a spatially periodi...
journal_title:Ultrasonics
pub_type: 杂志文章
doi:10.1016/j.ultras.2008.04.007
更新日期:2009-01-01 00:00:00
abstract::Speckle tracking methods overcome the major limitations of current Doppler methods for flow imaging and quantification: angle dependence and aliasing. In this paper, we review the development of speckle tracking, with particular attention to the advantages and limitations of two-dimensional algorithms that use a singl...
journal_title:Ultrasonics
pub_type: 杂志文章
doi:10.1016/s0041-624x(99)00182-1
更新日期:2000-03-01 00:00:00
abstract::Today, sophisticated instruments and algorithms used for process control allow the efficient production of substances with the quality guaranteed to the customer. However, production and management techniques are changing. This article aims to analyze trends resulting from those changes from the point of view of ultra...
journal_title:Ultrasonics
pub_type: 杂志文章
doi:10.1016/j.ultras.2006.05.047
更新日期:2006-12-22 00:00:00
abstract::In this paper a high intensity focused ultrasound (FUS) phantom model was developed, in order to be used in experiments for Blood Brain Barrier (BBB) disruption. The target was to create a phantom model that represents the disruption of the BBB during ultrasound application. An appropriate experimental setup was creat...
journal_title:Ultrasonics
pub_type: 杂志文章
doi:10.1016/j.ultras.2020.106244
更新日期:2021-02-01 00:00:00
abstract::This will be a discussion of the non-invasive determination of the viscosity of a non-Newtonian fluid in laminar pipe flow over the range of shear rates present in the pipe. The procedure used requires knowledge of the flow profile in and the pressure drop along a long straight run of pipe. The profile is determined b...
journal_title:Ultrasonics
pub_type: 杂志文章
doi:10.1016/j.ultras.2006.05.027
更新日期:2006-12-22 00:00:00
abstract::Ultrasound evaluation permits the state of rocks to be determined quickly and cheaply, satisfying the demands faced by today's producers of ornamental stone, such as environmental sustainability, durability and safety of use. The basic objective of the present work is to analyse and develop the usefulness of ultrasoun...
journal_title:Ultrasonics
pub_type: 杂志文章
doi:10.1016/j.ultras.2013.06.006
更新日期:2014-01-01 00:00:00
abstract::Acoustic scattering phenomena from complex immersed elastic shells are studied by high-speed Schlieren visualization for spark-generated spherical quasi-Dirac excitations. The situations considered are air-filled cylindrical shells under normal insonification and air-filled cylindrical shells soldered at one end with ...
journal_title:Ultrasonics
pub_type: 杂志文章
doi:10.1016/s0041-624x(99)00165-1
更新日期:2000-03-01 00:00:00
abstract::The mechanical pre-stress applied in piezotransducers used to generate high power ultrasound is needed to avoid ceramics fracture on traction cycle. Pre-stress levels inferior to 50 MPa can yield resonance shifting due to effectiveness of acoustic coupling between transducer pieces. Symmetrical transducers with differ...
journal_title:Ultrasonics
pub_type: 杂志文章
doi:10.1016/s0041-624x(03)00096-9
更新日期:2003-05-01 00:00:00
abstract::The increasing number of concrete structures with symptoms of premature deterioration due to environmental action demands procedures to estimate the durability of this type of component. Concrete durability is related to porosity, which determines the intensity of interactions of the material with aggressive agents. T...
journal_title:Ultrasonics
pub_type: 杂志文章
doi:10.1016/s0041-624x(99)00095-5
更新日期:2000-03-01 00:00:00
abstract::Experimental results of ultrasound of varying frequency (0.8-5.0 MHz) propagating in cold drawn wires of stainless steel and aluminium ranging in diameter from 0.25 to 1.21 mm are in close agreement with theoretical predictions. This agreement is maintained when the coupling medium between the wire and the ultrasound ...
journal_title:Ultrasonics
pub_type: 杂志文章
doi:10.1016/0041-624x(89)90021-8
更新日期:1989-03-01 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::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::In general, the design and analysis of ultrasonic motor and motor's control strategy are based on mathematical model. The academic model is widely used in the analysis of traveling wave ultrasonic motor (TWUSM). But the dispersive characteristic of piezoelectric ceramics and other complicated process, such as the fric...
journal_title:Ultrasonics
pub_type: 杂志文章
doi:10.1016/j.ultras.2013.09.012
更新日期:2014-02-01 00:00:00
abstract::Recent achievements of nonlinear acoustics concerning the realization of solitons and solitary waves in crystals and their surfaces attained by nanosecond and picosecond laser ultrasonics are discussed and compared. The corresponding pump-probe setups are described, which allow an all-optical contact-free excitation a...
journal_title:Ultrasonics
pub_type: 杂志文章
doi:10.1016/j.ultras.2009.08.003
更新日期:2010-02-01 00:00:00
abstract::We propose a method for evaluating the size of the laser-induced breakdown region in water based on the detection and analysis of optodynamic waves. The breakdown region is an optodynamic source of pressure waves that propagate into the surrounding liquid as an ultrasonic pulse. In the experiment the optical breakdown...
journal_title:Ultrasonics
pub_type: 杂志文章
doi:10.1016/j.ultras.2006.05.078
更新日期:2006-12-22 00:00:00
abstract::Conventionally, the ultrasonic polar scan (UPS) records the amplitude or time-of-flight in transmission using short ultrasonic pulses for a wide range of incidence angles, resulting in a fingerprint of the critical bulk wave angles of the material at the insonified spot. Here, we investigate the use of quasi-harmonic ...
journal_title:Ultrasonics
pub_type: 杂志文章
doi:10.1016/j.ultras.2015.01.002
更新日期:2015-04-01 00:00:00