Quantitative non-linear ultrasonic imaging of targets with significant acoustic impedance contrast--an experimental study.
This study deals with the reconstruction, from ultrasonic measured data, of the sound speed profile of a penetrable two-dimensional target of arbitrary cross-section embedded in an infinite medium. Green's theorem is used to obtain a domain integral representation of the acoustical scattered field, and a discrete formulation of the inverse problem is obtained using a moment method. An iterative non-linear algorithm minimizing the discrepancy between the measured and computed scattered fields is used to reconstruct the sound speed profile in the region of interest. The minimization process is performed using a conjugated-gradient method. An experimental study with significant acoustical impedance contrast targets immersed in water was performed. Images of the sound speed profile obtained by inversion of experimental data are presented.
Laboratoire de Mécanique et d'Acoustique, CNRS, UPR 7051, Aix-Marseille Université, Centrale Marseille, F-13402 Marseille Cedex 20, France. guillermin@lma.cnrs-mrs.fr
Régine
R
Guillermin
Philippe
P
Lasaygues
Guy
G
Rabau
Jean-Pierre
JP
Lefebvre
D000465:Algorithms; D003198:Computer Simulation; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D009038:Motion; D017711:Nonlinear Dynamics; D009716:Numerical Analysis, Computer-Assisted; D019047:Phantoms, Imaging; D012542:Scattering, Radiation; D013016:Sound; D013997:Time Factors; D014159:Transducers; D014465:Ultrasonics / Q000295:instrumentation / Q000379:methods*; D014463:Ultrasonography / Q000295:instrumentation / Q000379:methods*