• Aucun résultat trouvé

« Ultrasonic Backscatter Coefficient Estimates in a Soft Tissue Mimicking Phantom»

N/A
N/A
Protected

Academic year: 2021

Partager "« Ultrasonic Backscatter Coefficient Estimates in a Soft Tissue Mimicking Phantom»"

Copied!
1
0
0

Texte intégral

(1)

Nesrine Houhat

Technical and Scientific Research Center on Welding and Control (CSC),

Algiers, Algeria Email: n.houhat@csc.dz

Tarek Boutkedjirt

University of Sciences and Technology Houari Boumediene (U.S.T.H.B)

Algiers, Algeria

Email: tarek_boutkedjirt@hotmail.com

« Ultrasonic Backscatter Coefficient Estimates in a Soft Tissue Mimicking Phantom»

The ultimate goal of characterization methods based on the backscatter coefficient (BSC) estimates is to obtain structural information about samples independently of the measurement system. In the current study, measurements of the BSC were obtained from Tissue Mimicking Materials (TMM) or phantoms. These consisted of a mixture of gelatin and distilled water containing microscopic graphite particles with a mean radius of 18 micrometers, which were randomly distributed. Phantoms concentrations ranged from 50 to 200 g of graphite per liter of gelatin. Two BSC estimation methods were used and their results were compared to Faran’s scattering theory which allowed the estimation of the number density of graphite particles in the phantoms. Moreover, measurements of the attenuation coefficient and the ultrasonic propagation velocity in phantoms were performed. The evolution of the attenuation coefficient and the BSC as a function of frequency and scatterers’s concentration in a frequency range from 1.5 MHz to 6 MHz will be presented using two transducers of nominal frequencies 2.25 MHz and 5 MHz. Decreasing of the attenuation coefficient with frequency and graphite concentration will be showed.

Mots clés: Ultrasound, Attenuation, backscattering, TMM.

Références

Documents relatifs

(*) Added in proof : Progress on this problem has now been achieved and will appear elsewhere... In section 1 we review complex scaling outside a strictly convex set and add

Having demonstrated that enhanced scavenging in the presence of a combination of chelators is observed for iron removal from transferrin at high deferiprone concentrations,

Our density data analyses (14-17), performed in order to improve the first models which were mainly based on orbital data of satellites with perigee greater than 250 km,

The circular tank wasrotatedinan anliclockwisedirection and etfectivelymodels northem hemisphere dynamicson a polar p-plane A buoyancy source injects fluid into the tank to create

This is to be expected since, as men- tioned by Hjort and Jones (1996), for small to moderate h the locally parametric estimator utilises primarily local properties of the model g ,

The second procedure is of theoretical interest and leads to a general model selection theorem from which we derive rates of convergence over a very wide range of possibly

As proved in Hough et al [9], the distribution of a (finite) determinantal process N can be viewed as a mixture of densities of some determi- nantal projection processes..

Between February and September 2017 several missions were organised in Athens where the agents interviewed asylum seekers from Syria, Iraq, Iran, Palestine (mainly from Syria),