Ultrasound Flow Motion Detection Using Reverse Golay Codes for Decoding

Golay-coded excitation improves the system signal to noise ratio (SNR) and achieves better penetration for B-mode imaging. However, code degradation from tissue (or flow) motion during the interval between two transmit firing affects performance. This paper presents a qualitative method for ultrasound flow motion detection and stationary tissue enhancement. A pair of Golay codes is first transmitted, followed by another pair of Golay codes with the round-trip propagation delay. The receiver filtering follows two paths. First, static signals are recovered by the original two pairs of Golay code. Second, moving signals are recovered by the reverse of the original two code pairs. The filtering result from the second path shows moving signals only where the static signals have been suppressed. By subtracting the second path results from that in the first path we obtain a static signal with better SNR without motion artifacts.