The Study Of Synthetic-Aperture Imaging In B-Mode Ultrasonic Imaging Systems

B-mode ultrasound diagnosis, one of the most important diagnosis means, is used widely in medical field. The technology is developing towards improving the resolving power and extending the diagnosis scope. Synthetic-aperture ultrasonic imaging, using synthetic-aperture technology in ultrasonic imaging, can improve the lateral resolution with little aperture and low frequency transducer. In image reconstruction, some advanced digital image processing technology can be used to improve the image quality and signal-to-noise ratio (SNR).In this paper a new technology for synthetic-aperture focusing ultrasonic imaging, the digital envelope detection, is introduced, and a simulated result is given, the simulated parameters are chosen in accordance with a proposed experimental system. Based on the theory, a virtual ultrasonic imaging system of synthetic-aperture focusing is designed. A card based on PCI bus is designed to stimulate the transducer and acquire data. The appliance software processes the data with synthetic-aperture algorithm and displays the imaging result. At the end of paper, some question and the resolving methods are discussed.