Improving biomedical ultrasonic imaging systems through coded excitation and pulse compression

Coded excitation and pulse compression techniques are being employed in biomedical ultrasonic imaging systems in order to improve image quality. Traditionally, the rationale for using coded excitation techniques in biomedical ultrasonic imaging was to increase the signal‐to‐noise ratio (SNR) of backscattered signals without increasing the pressure amplitudes above the thresholds predicted to produce bioeffects. Furthermore, coding schemes combined with pulse compression would allow the spatial resolution to be preserved. Recently, unique coded excitation schemes have been developed [i.e., the resolution enhancement compression (REC) technique] that not only produce a significant increase in SNR but also a doubling of the bandwidth of the ultrasonic imaging system. In conventional ultrasound B‐mode imaging, the increased bandwidth provided by the REC technique could be used to improve the axial resolution of the ultrasonic imaging system or traded off to improve the contrast resolution of the ultrasonic im...