Low-cost volumetric imaging with large footprint 11x11-element matrix array probe on a 128 channel ultrasound research scanner

Volumetric imaging in real time can only be realized using matrix array transducers and electronic beam steering requiring cost intensive ultrasound devices. Furthermore, matrix array transducers typically come with a small footprint that limits the total amount of energy that can be applied to the tissue caused by fulfilling the l/2 element pitch criteria for best beam steering possibilities. This results in a reduction of maximum penetration of the sound wave caused by its attenuation and therefore reduces the possible imaging depth. By choosing a larger element pitch of 2.8125 mm (3.6x lambda) in both dimensions in our approach, we increase the maximum amount of energy to be generated while reducing beam steering capabilities. While generating enough acoustic energy to image deeper tissue, this design significantly limits the beam steering possibilities still allowing for plane wave compounding. Pre-beamformed channel data from 25 plane waves each was reconstructed to volumes on the GPU after transfer from the ""DiPhAS"" ultrasound research scanner. The software based receive beamforming process allows real time volumetric imaging of up to 75 Hz. The resulting imaging quality is reduced caused by the large element spacing but can be used for motion tracking or real time process monitoring.