Depth-independent narrow beamwidth 3D ultrasonic image formation technique

Abstract

A technique is proposed that generates a depth-independent and narrow beamwidth 3D ultrasonic image. A high-frequency, wide-bandwidth spherical transducer is scanned in 2D along Cartesian coordinates. The received wideband ultrasonic pulses are dynamically focused by means of correcting the spatial spectrum of signals for various temporal frequencies. The main procedures of the algorithm consist in the direct and inverse fast Fourier transforms by time and by two spatial Cartesian coordinates.