Frequency and concentration dependence of the ultrasonic backscatter coefficient in a soft tissue mimicking material

Nesrine Houhat , Tarek Boutkedjirt

In medical ultrasound, the backscatter coefficient is used to quantify the scattering properties of biological tissues. It is defined as the differential scattering cross section per unit volume for a scattering angle of 180°. In this study, measurements of the backscatter coefficient are made on Tissues Mimicking Materials (TMM). These are materials the acoustic properties of which (velocity propagation, attenuation, scattering) are close to those of biological tissues. Measurements of this coefficient have been achieved on a mixture of gelatin and distilled water containing graphite particles of mean radius 18 µm, which were randomly distributed. TMM samples with graphite concentrations ranging from 50 to 200 g per liter of gelatin have been investigated. The backscatter coefficient was evaluated using both Sigelman and Reid [JASA 53, 1351 (1973)] and Chen [IEEE Trans. UFFC 44, 515 (1997)] methods in a frequency range around 5 MHz. The evolution of this coefficient as a function of frequency for different scatterers concentration will be presented. Comparison of experimental values with those predicted by the Faran theory [JASA 23, 405 (1951)] permits the estimation of the number density of graphite particles in the TMM.

Mots clés: Ultrasound; Tissues Mimicking Materials; Biological phantom; Backscatter coefficient

Domaines: Acoustique [physics.class-ph]

Nesrine Houhat, Tarek Boutkedjirt. Frequency and concentration dependence of the ultrasonic backscatter coefficient in a soft tissue mimicking material. Acoustics 2012, Apr 2012, Nantes, France. ⟨hal-00810917⟩