A combination of pixel-based beamforming and Wiener filter to improve ultrasound image quality

We previously developed coherent pixel-based beamforming to generate two-way focused ultrasound images, where the transmit focusing is achieved by accumulating data from multiple transmits. Most of the impact of this, however, is on the lateral resolution which directly benefits from the large "effective" aperture. In this study we extend the field pattern analysis and form a new Wiener filter that can be combined with coherent pixel-based processing to enhance the axial resolution. The Wiener filter is applied to the received waveform before performing the spatiotemporal mapping. The proposed combination is evaluated through simulation and on data obtained in a phantom study. The imaging results show that the new combination improves on the axial resolution of the coherent pixel-based approach while still maintaining its good performance in lateral resolution and imaging contrast.