Optimization of virtual sources distribution in 3D echography

Coherent compounding may be applied with diverging waves on 2D ultrasound probes to overcome the problem of small aperture probe and meet the requirement for high frame rate 3D imaging, as in transthoracic echography for example. Deterministic distributions of the virtual sources are often used in practice. The compromise between contrast and resolution has to be managed according to the application, and this will affect the distribution of the virtual sources. This study proposes to use a multi-objective optimization genetic algorithm to allow some freedom in the management of this compromise. The solutions obtained are compared to the case of a regular and a spiral distribution of sources. The results show that virtual sources distribution can produce images with the emphasis on either contrast or lateral resolution, and validate observations already reported in the literature.