Sparse arrays for real-time 3D imaging, simulated and experimental results

This work presents the outputs from a project which aimed to lay the foundation of a 3D ultrasound imaging system where the emphasis was on real-time data acquisition and near real-time data visualization. To be able more precisely to describe the behavior of a sparse array system, a 25 Gbyte dataset containing every transmit and receive combination of a 50/spl times/50-element fully connected 3 MHz array has been collected. The data have been processed off line on a cluster of 150 UNIX work stations to form experimental synthetic aperture 3D volume images. We propose new methods based on the principle of suppression of grating lobes to form symmetric and non-symmetric regular sparse periodic and radially periodic designs. The performance of the new layouts come close to that of dense arrays. Our designs have simplicity in construction, flexibility in the number of active elements and possibility to trade off sidelobe peaks against sidelobe energy.