High contrast Ultrafast 3D Ultrasound Imaging using Row Column specific Frame Multiply and Sum

Abstract: Row-column arrays have shown to be able to generate 3-D ultrafast ultrasound images with an order of magnitude less independent electronic channels than classic 2D matrix arrays. Unfortunately row-column array images suffer from major imaging artefacts due to the high side lobes. This paper proposes a row-column specific beamforming technique that exploits the incoherent nature of certain row column array artefacts. The geometric mean of the data from each row and column pair is taken prior to summation in beamforming, thus drastically reducing incoherent imaging artefacts compared to traditional coherent compounding. The effectiveness of this technique was demonstrated in silico, and the results show an average fivefold reduction in side-lobe levels. Significantly improved contrast was demonstrated with Tissue-to-noise ratio increasing from $\sim$10dB to $\sim$30dB and Tissue Contrast Ratio increasing from $\sim$21dB to $\sim$42dB when using the proposed new method compared to Delay and Sum. These new techniques allowed for high quality 3D imaging whilst maintaining high frame rate potential.