Reference-phantom-free imaging of local attenuation coefficient in synthetic transmit aperture ultrasound imaging

The attenuation coefficient slope(ACS) is an essential property of biological tissues. Most of the present ACS estimation methods use spectrum-based approaches in B-mode imaging and need a reference phantom. A method to map ACS without a reference phantom is proposed in Synthetic Transmit Aperture ultrasound imaging. The diffraction effect in ACS estimation is studied. In this paper, the transducer bandwidth was divided into overlapping sub-bands, and each sub-band was used to reconstruct an image and yield the corresponding sub-band attenuation coefficient to obtain ACS. The feasibility of the proposed method was demonstrated in numerical simulations and experiments.