High frame rate ultrasonic imaging system based on the angular spectrum principle

A kind of high frame rate (HFR) 2D and 3D imaging method was developed by Jianyu Lu in 1997. Because only one transmission is required to construct a frame of image, this method can reach an ultra high frame rate (about 3750 volumes or frames per second for biological soft tissues at a depth of 200 mm). In this paper, a new HFR method is presented in the view of angular spectrum. Compared with conventional dynamic focusing method which uses delay-and-sum processing, and Lu's HFR method which uses a kind of special weighting on the received signal, the new method only uses the Fourier transform algorithm to construct image. So the system implementation of the method could be greatly simplified. During constructing image, several array beams with different parameter are used as transmitted signal, and the spectrum of a frame of image is obtained by synthesizing the image spectrums related to different transmit event. The simulation result shows that the solution not only suppresses the sidelobe of system greatly and obtains the high quality image, but also still keeps high frame rate to some extent.