High frame rate ultrasonic imaging through Fourier transform using an arbitrary known transmission field

The high frame rate (HFR) method, derived from the limited diffraction beams [Jian-yu Lu. 2D and 3D high frame rate imaging with limited diffraction beams. IEEE Trans Ultrason Ferroelectrics Freq Control 1997;44(4):839–56; Jian-yu Lu. Experimental study of high frame rate imaging with limited diffraction beams. IEEE Trans Ultrason Ferroelectrics Freq Control 1998;45(1):84–97; Hu Peng, Jianyu Lu, XueMei Han. High frame rate ultrasonic imaging system based on the angular spectrum principle. Ultrason 2006;44(Suppl):e97–9] theory, has a drawback that its imaging area, as wide as its array beam transmission field, can generally not be wider than the transducer is long; and that the only way to widen the area is to steer the transmission beams several times from different angles, which lowers the frame rate. Besides, the array beam field is quite demanding to produce.To widen the imaged area, we developed an extended, more general HFR method for 2D imaging. It allows any form of transmission field as long as the field is known, and it achieves the frame per transmission imaging rate.For verification, computer simulations use a linear transducer array and a cylindrical diffraction transmission field defined by the zero order Hankle function. The output images are in the sector format and have low sidelobes. The simulation results are consistent with our theory.