title: Simulation of ultrasonic imaging with linear arrays in causal absorptive media.
abstract: Rigorous and efficient numerical methods are presented for simulation of acoustic propagation in a medium where the absorption is described by relaxation processes. It is shown how FFT-based algorithms can be used to simulate ultrasound images in pulse-echo mode. General expressions are obtained for the complex wavenumber in a relaxing medium. A fit to measurements in biological media shows the appropriateness of the model. The wavenumber is applied to three FFT-based extrapolation operators, which are implemented in a weak form to reduce spatial aliasing. The influence of the absorptive medium on the quality of images obtained with a linear array transducer is demonstrated. It is shown that, for moderately absorbing media, the absorption has a large influence on the images, whereas the dispersion has a negligible effect on the images.
authors: Department of Ophthalmology, St. Radboud University Hospital, Nijmegen, The Netherlands.
authors: A P
authors: AP
authors: Berkhoff
authors: J M
authors: JM
authors: Thijssen
authors: R J
authors: RJ
authors: Homan
mesh_terms: D000042:Absorption; D000162:Acoustics; D000465:Algorithms; D001672:Biocompatible Materials; D003198:Computer Simulation; D005583:Fourier Analysis; D007089:Image Enhancement; D008962:Models, Theoretical; D014159:Transducers; D014463:Ultrasonography / Q000295:instrumentation
chemical_list: D001672:Biocompatible Materials