Convex Array With Variable Spacings (CAVS) for Ultrafast Ultrasound Diverging-Wave Imaging

The synthetic focusing of coherent plane-wave compounding (CPWC) has gradually developed from ultrasound linear array to convex array. The field of view (FOV) has been expanded compared to that of the linear array. However, the existing technology does not make the most of the convex structural advantages and FOV is greatly limited by the element number of a convex array. In this paper, based on the convex array of diverging wave (DW) imaging theory and the special structure design principles, the elements of the convex array probe are unequally spaced for better imaging quality and wider FOV. Firstly, the sound field pattern was simulated for sidelobe comparison. Then, DW imaging of the new convex array was simulated and the experiment was carried out on the tissue-mimicking ultrasound phantom using the commercial probe. Comparisons of lateral and axial variations illustrated that the convex array with variable spacings (CAVS) does improve the imaging quality when compared to the given convex array with uniform spacings. Finally, we conclude that CAVS can further extend the FOV of DW imaging by taking advantage of the structure of convex array and variable element spacings.