Phase insensitive ultrasonic attenuation coefficient determination of fresh bovine liver over an extended frequency range

The ultrasonic attenuation coefficient of fresh bovine liver was determined by the phase insensitive techniques of the radiation force balance at 1.37, 4.15, 6.90, and 9.65 MHz, and the scanning laser acoustic microscope (SLAM) at 100 MHz. A least squares fit of the ultrasonic attenuation coefficient (in Np/cm) vs ultrasonic frequency (in MHz) to the 1–10 MHz data yields A = 0.043 f1.266 (r**2 = 0.895) and to the 1–100 MHz data yields A = 0.043 f1.270 (r**2 = 0.954). The following observations can be made: the greatest frequency range (2 decades) over which ultrasonic frequency has been determined for the same specimens. (2) This is the first time it has been shown that the frequency dependence of attenuation remains essentially unchanged over this large frequency range. (3) The frequency dependence is slightly greater than has been observed from the various literature compilations. (4) The attenuation coefficient magnitudes are the lowest values yet determined for fresh liver. (5) The attenuation magnitudes are from 1.3 to 2.2 times greater than the ultrasonic absorption values in the same tissue.