Optimal virtual sources distribution in 3-D diverging wave ultrasound imaging: an experimental study

The use of 2-D array probes to perform 3-D ultrasound imaging is still investigated in many domains. The extension from 2-D to 3-D imaging causes problems because of the need to control a very large number of elements on the probe. It might be overcome by using 2-D sparse array. This problem has been recently shown that sparse 2-D arrays can be used for 3-D fast ultrasound imaging based on the transmission of Diverging Waves (DW). The aim of this work is to experimentally analyze how the distribution of a given number (25) of Virtual Sources (VS) over a predefined area affects the images obtained with one fully populated probe and two sparse array probes, respectively. In order to do that, gridded and spiral distributions of virtual sources have been implemented. The results show that with the spiral distribution there is a general improvement of the contrast despite of a degradation on both lateral and axial resolutions.