[Implementation of sector imaging mode with high signal-to-noise ratio in the high frame rate ultrasonic imaging system].

The high frame rate (HFR) ultrasonic imaging system, which is developed with limited diffraction beams, constructs images at a high frame rate. However the rectangular imaging area, to some extent, restricts the far field imaging information. At the same time, because of one transmission for constructing image, the system suffers from low SNR. In this paper we present a computationally efficient method to construct sector mode image and to increase the SNR in HFR system. The method uses Golay complementary sequence as excitation to realize two transmission events. Each event simultaneously transmits two plane waves with different transmission angle. Then the received echo signals related to different angle are separated according to orthogonality of Golay complementary sequence and used to construct two images of different area by HFR method. Finally the two images are synthesized to one frame of sector mode image.