A Spatially Weighted Regularization Method for Attenuation Coefficient Estimation

Existing methods for measuring the ultrasonic attenuation coefficient estimate (ACE) fail to take into account the effect of tissue heterogeneity. We propose a total variation (TV) regularization based method, where the local regularization will be modulated as a function of envelope signal-to-noise-ratio deviation, an indicator of tissue heterogeneity. We evaluate our approach using three physical phantoms with different configurations. We also demonstrate the application of the method for placenta ex vivo. The proposed method results in significant improvement in ACE measurement compared to the reference phantom method for all the experiments. Specifically, the method shows promising results in the presence of heterogeneity, exceeding the performance of both reference phantom and unweighted total variation regularization in terms of accuracy, precision and resolution-precision trade-off.