Ultrafast ultrasound imaging using a resolution and bandwidth enhancement technique

One of the objectives in ultrasonic imaging is to improve the spatial resolution of the acquired images. The axial resolution is determined by the transducer bandwidth and the beamforming process. The resolution enhancement compression (REC) technique allows extending the bandwidth by combining the concepts of frequency and amplitude modulated excitation with modified Wiener filter compression. More precisely, REC boosts the signal energy in the transition frequency bands, where the energy transduction of the ultrasound probe is less efficient. Therefore, one of the advantages of this technique is a significant gain of the signal-to-noise ratio. In this work, the first experimental implementation of REC combined with coherent plane wave compounding was conducted. The experimental results show that REC is capable of obtaining a better image quality than conventional pulse (CP) imaging. The bandwidth of the power spectra of the reflection from a nylon wire is boosted by 21% (at −6dB) compared to CP. The axial resolution is also improved for the wire by 16%. The B-mode images obtained from the phantom containing a cyst also reveals an improvement of the SNR and CNR by 15% and 351%, respectively, for REC compared to CP.