A Novel Coded Excitation Imaging Platform for Ultra-High Frequency (>100 MHz) Ultrasound Applications

Ultra-high frequency (UHF, >100 MHz) ultrasound imaging has significant potential applications in musculoskeletal anatomy, skin, oral mucosa, and the eyes as a new high-resolution imaging technique. However, large acoustic attenuation of biological tissues greatly limits the depth of penetration of UHF ultrasound. Improving penetration depth while maintaining high-definition images is of clinical importance for UHF ultrasound imaging. Coded excitation imaging is known to be an effective method to increase the penetration depth of high-frequency ultrasound. Nevertheless, the feasibility of this technique has not yet been established in UHF ultrasound imaging. In addition, conventional coded excitation imaging systems are bulky, expensive, and lack flexibility. In this study, we propose a coded excitation imaging platform for UHF ultrasound. The platform integrates a high-performance ultrasound transmitter and a high sampling rate signal receiver to enable UHF ultrasound applications. A UHF ultrasound transducer was developed using LiNbO3 with a center frequency of 121.5 MHz to validate the imaging performance of the platform. High voltage short pulse and chirp coded pulse are used for the imaging, and the data show that the proposed coded method improved the signal-to-noise ratio (SNR) by nearly 10 dB at a similar spatial resolution. The results indicate that this platform has promising applications in UHF ultrasound imaging.