First experimental implementation of a bandwidth enhancement pulse compression technique on an ultrasound array imaging system

Extending the effective bandwidth of an ultrasonic imaging transducer is advantageous for both qualitative and quantitative imaging methods. The resolution enhancement compression (REC) technique allows to accomplish this task by combining frequency and amplitude modulated excitation with modified Wiener filter compression. Although promising results have been reported, the experimental implementation of the REC technique has been so far limited to single-element transducer systems. With the advent of array-based imaging systems with arbitrary waveform generation capabilities, the implementation of REC with multi-element transducers is now feasible. In this work, experimental results of the first implementation of the REC technique on an ultrasound array system are presented. Data were obtained from both wire and speckle-based targets using an excitation signal designed to provide a 33% increase in bandwidth over the one obtained with a broadband pulse excitation. The bandwidth was experimentally determined to improve by 23% and 34% for the wire and speckle-based phantoms, respectively, when using the bandwidth enhancement compression technique. Further, the axial resolution as derived from the modulation transfer function of the envelope of the wire targets improved by 29%. The results of this proof-of-concept study suggest that the REC technique can be successfully implemented in an array-based ultrasonic imaging system.