Experimental investigation of acoustic backscattered field from a medium with random and aligned fibers

Abstract

Some soft tissues, such as skeletal muscles, have fiber-like structures that make them anisotropic. Acoustic backscattering from such tissues or media has been of interest to many scientists in biomedical fields because it complicates interpretation of imaging data. Backscatter coefficient measurements show diagnostic promise for this purpose both in vitro and in vivo. Many parameters, e.g., effective scatterer diameter or average scattering strength, can be estimated with acoustic backscatter measurements. In the present work, we experimentally study the backscatter coefficient of a medium with aligned or random fibers and estimate the effect of fiber orientation upon the backscattered field and the estimated scatterer diameter. Using an experimental approach, we explore the relationship between the backscatter coefficient of a medium with multiple fibers and with a single fiber. In addition, we investigate the effect of the spatial Fourier transform of the fiber distribution in the medium with its frequency dependence of backscatter coefficients. The experimental results show that backscatter coefficients of a medium with random fibers can be modeled by the product of number density of fibers, backscatter coefficients of the same single fiber, and the spatial Fourier transform of the fiber distribution.Some soft tissues, such as skeletal muscles, have fiber-like structures that make them anisotropic. Acoustic backscattering from such tissues or media has been of interest to many scientists in biomedical fields because it complicates interpretation of imaging data. Backscatter coefficient measurements show diagnostic promise for this purpose both in vitro and in vivo. Many parameters, e.g., effective scatterer diameter or average scattering strength, can be estimated with acoustic backscatter measurements. In the present work, we experimentally study the backscatter coefficient of a medium with aligned or random fibers and estimate the effect of fiber orientation upon the backscattered field and the estimated scatterer diameter. Using an experimental approach, we explore the relationship between the backscatter coefficient of a medium with multiple fibers and with a single fiber. In addition, we investigate the effect of the spatial Fourier transform of the fiber distribution in the medium with its frequ...