Attenuation estimation in highly attenuating media using high frequencies: a comparison study between different mean frequency estimators

Attenuation estimation from the ultrasound signal backscattered by biological tissues with the “centroid algorithm” requires a mean frequency estimator. We previously presented the second-order auto-regressive (AR2) model for mean frequency and attenuation estimation. In this paper, we focus on a new mean frequency estimator based on an approximation of the first derivative of the autocorrelation function of the demodulated echographic signal at the origin, first introduced for Doppler signal analysis. This adapted estimator (AE) is compared with the AR2 modeling and with the classical Fourier spectrogram technique (FFT) in case of simulated echographic signals using a 20 MHz frequency probe and experimental signals obtained from a scattering phantom with calibrated attenuation. This study shows that the AE and the AR2 estimators lead to a better attenuation estimation than the FFT technique. First in vitro results on porcine skin are shown. These results offer promises for determining attenuation in highly attenuating media either because of their structure or because high frequencies are used