Coded Transmission in Synthetic Transmit Aperture Ultrasound Imaging Method

Abstract

The paper presents the study of synthetic transmit aperture method applying the Golay coded transmission for medical ultrasound imaging. Longer coded excitation allows to increase the total energy of the transmitted signal without incr easing the peak pressure. Signal-to-noise ratio and penetration dep th are improved maintaining high ultrasound image resolution. In the work the 128-element linear transducer array with 0.3 mm inter-element spacing excited by one cycle and the 8 and 16-bit Golay coded sequences at nominal frequencies 4 MHz was used. Single element transmission aperture was used to ge nerate a spherical wave covering the full image region and all the ele ments received the echo signals. The comparison of 2D ultrasound images of the wire phantom as well as of the tissue mimicking phantom is presented to demonstrate the benefits of the coded transmission. The results were obtained using the synthetic aperture algorithm w ith transmit and receive signals correction based on a single elemen t directivity function.