title: Sources of image degradation in fundamental and harmonic ultrasound imaging: a nonlinear, full-wave, simulation study.
abstract: A full-wave equation that describes nonlinear propagation in a heterogeneous attenuating medium is solved numerically with finite differences in the time domain. This numerical method is used to simulate propagation of a diagnostic ultrasound pulse through a measured representation of the human abdomen with heterogeneities in speed of sound, attenuation, density, and nonlinearity. Conventional delay-and-sum beamforming is used to generate point spread functions (PSFs) that display the effects of these heterogeneities. For the particular imaging configuration that is modeled, these PSFs reveal that the primary source of degradation in fundamental imaging is due to reverberation from near-field structures. Compared with fundamental imaging, reverberation clutter in harmonic imaging is 27.1 dB lower. Simulated tissue with uniform velocity but unchanged impedance characteristics indicates that for harmonic imaging, the primary source of degradation is phase aberration.
authors.affiliation: Institut Langevin, Ecole Supérieure de Physique et de Chimie Industrielles de la ville de Paris (ESPCI) ParisTech, Centre National de la Recherche Scientifique (CNRS), UMR 7587, Paris, France.
authors.forename: Gianmarco F
authors.initials: GF
authors.lastname: Pinton
authors.forename: Gregg E
authors.initials: GE
authors.lastname: Trahey
authors.forename: Jeremy J
authors.initials: JJ
authors.lastname: Dahl
mesh_terms: D000005:Abdomen / Q000000981:diagnostic imaging; D000273:Adipose Tissue / Q000000981:diagnostic imaging; D000818:Animals; D015992:Body Mass Index; D003198:Computer Simulation; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008954:Models, Biological; D009132:Muscles / Q000000981:diagnostic imaging; D017711:Nonlinear Dynamics; D015203:Reproducibility of Results; D013552:Swine; D014463:Ultrasonography / Q000592:standards*