Three-way dynamic focusing for ultrasound imaging

The receive dynamic focusing technique has been employed to improve the lateral resolution of medical ultrasound imaging. A new two-way dynamic focusing algorithm has been introduced to focus the ultrasound waves at all imaging points both in transmit and receive. We propose a three-way dynamic focusing technique to further improve the lateral resolution. To implement the proposed technique in real time, a novel synthetic aperture method is also proposed, in which each array element is excited individually and the resulting pulse echoes are received at all elements of the corresponding subaperture. After repeating the transmit-and-receive step for all array elements, the three-way dynamic focusing is achieved by combining a synthetic aperture algorithm for two-way dynamic focusing and a synthetic focusing technique for transmit dynamic focusing. Computer simulation results show that the proposed scheme provides significantly improved lateral resolution at all depths compared with other focusing methods.