Non-Rayleigh statistics of ultrasonic backscattered signals

摘要

The statistics of the envelope of the backscattered signal fromntissues have been known to vary from the well-known Rayleigh model. ThenK-distribution is used to model this non-Rayleigh behavior, since thengeneralized K-distribution encompasses a wide range of distributionsnlike Rayleigh, Lognormal, and Rician. Computer simulations werenconducted using a simple one-dimensional discrete scattering model toninvestigate the properties of the echo envelope. Significant departuresnfrom Rayleigh statistics were seen as the scattering cross sections ofnthe scatterers became random. The validity of this model was also testednusing data from tissue mimicking phantoms. Results indicate that thendensity function of the envelope can be modeled by the K-distributionnand the parameters of the K-distribution can provide information on thennature of the scattering region in terms of the number as well as thenscattering cross sections of the scatterers