查看文章

The attenuation coefficient has potential in tissue characterization. Previously, it was observed that the accuracy of estimates of the attenuation coefficient slope (ACS) obtained using the spectral-log-difference technique (SLD) degraded due to nonlinear distortion. Based on these observations regarding estimates of the ACS, (i.e., the difference between ACS estimated at high and low pressures, which is called excess ACS in this work), a heuristic approach was devised for determining the nonlinearity parameter, B/A, of a medium. A total of 16 numerical phantoms using the k-Wave simulation package were constructed having spatially random distributions of acoustic density in a 3D grid to generate backscattered signals. To estimate ACS values from the phantoms, we used the SLD technique. The uniform numerical phantoms varied in their properties with B/A values of 6, 8, 10 or 12 and ACS values of 0.3, 0.7, 1.1 …