Coherent Multi-Transducer Ultrasound Imaging through aberrating media

Transducers with larger aperture size are desirable in ultrasound imaging to improve resolution and image quality. However, in practice inhomogeneities and aberrating layers cause phase errors that limit the benefits of increased aperture size. A coherent multi-transducer ultrasound imaging system (CoMTUS) enables an extended effective aperture through coherent combination of multiple transducers. The optimal beamforming parameters, which include the transducer locations and the average speed of sound in the medium, are deduced by maximizing the coherence of the received radio frequency data by crosscorrelation. In this work, the robustness of the CoMTUS approach in the presence of acoustic clutter and aberration is investigated by both simulated and in-vitro results. Results show that CoMTUS improves ultrasound imaging quality in terms of resolution, and also suppresses phase aberration effects along with clutter, providing benefits to image quality compared with a single probe imaging system. Overall resolution was unaffected by aberration and improved up to 70% in the CoMTUS.