title: Influence of viscoelastic and viscous absorption on ultrasonic wave propagation in cortical bone: Application to axial transmission.
abstract: Cortical bone and the surrounding soft tissues are attenuating and heterogeneous media, which might affect the signals measured with axial transmission devices. This work aims at evaluating the effect of the heterogeneous acoustic absorption in bone and in soft tissues on the bone ultrasonic response. Therefore, a two-dimensional finite element time-domain method is derived to model transient wave propagation in a three-layer medium composed of an inhomogeneous transverse isotropic viscoelastic solid layer, sandwiched between two viscous fluid layers. The model couples viscous acoustic propagation in both fluid media with the anisotropic viscoelastic response of the solid. A constant spatial gradient of material properties is considered for two values of bone thicknesses (0.6 and 4 mm). In the studied configuration, absorption in the surrounding fluid tissues does not affect the results, whereas bone viscoelastic properties have a significant effect on the first arriving signal (FAS) velocity. For a thin bone, the FAS velocity is governed by the spatially averaged bone properties. For a thick bone, the FAS velocity may be predicted using a one-dimensional model.
authors.affiliation: Laboratoire Modelisation et Simulation Multi-Echelle, Universite Paris-Est, UMR 8208 CNRS, 94010 Creteil Cedex, France. salah.naili@univ-paris-est.fr
authors.forename: Salah
authors.initials: S
authors.lastname: Naili
authors.forename: Mai-Ba
authors.initials: MB
authors.lastname: Vu
authors.forename: Quentin
authors.initials: Q
authors.lastname: Grimal
authors.forename: Maryline
authors.initials: M
authors.lastname: Talmant
authors.forename: Christophe
authors.initials: C
authors.lastname: Desceliers
authors.forename: Christian
authors.initials: C
authors.lastname: Soize
authors.forename: Guillaume
authors.initials: G
authors.lastname: Haïat
mesh_terms: D000042:Absorption; D000818:Animals; D016880:Anisotropy; D015519:Bone Density; D001853:Bone Marrow / Q000000981:diagnostic imaging; D001842:Bone and Bones / Q000737:chemistry / Q000000981:diagnostic imaging*; D003198:Computer Simulation; D020342:Finite Element Analysis; D006801:Humans; D008954:Models, Biological; D016062:Porosity; D014465:Ultrasonics; D014463:Ultrasonography; D055682:Viscoelastic Substances; D014783:Viscosity
chemical_list: D055682:Viscoelastic Substances