医学超声成像中的编码激励技术及其应用

与传统的脉冲回波成像技术相比 ,编码激励技术能够提高超声图像的信噪比或相应提高声束的穿透深度。本文首先介绍了编码激励成像系统的原理 ,并对医学超声诊断系统中的发射声强进行了分析 ,得出了采用编码激励技术提高超声图像信噪比的上限。然后阐述了发射编码的选取原则 ,详细介绍了白噪编码、伪随机码、Golay码、Chirp和伪 Chirp码等编码技术。最后 ,介绍了编码激励技术在 B模式成像、Doppler血流测量、B- flow成像和谐波成像中的应用。

Coded Excitation and Its Applications in Medical Ultrasound Imaging

Compared with medical ultrasonic pulse-echo imaging system, coded excitation system has the potential of higher SNR and deeper penetration depth. In this paper, the basic principle of coded excitation is introduced. Through acoustic intensity analysis, the maximum improvement of SNR of ultrasonic image with coded excitation is deduced. Then, guide lines to choose codes in ultrasonic imaging are introduced. Some codes, such as white noise, pseudo-random code, Golay code, Chirp and pseudo-chirp are described in details. At last, the applications of ultrasonic coded excitation in B-mode imaging, Doppler flow measurement, B-flow imaging and harmonics imaging are described.