TRANSMISSION OF OPTIMIZED PULSE WAVEFORMS FOR ULTRASONIC SUBHARMONIC IMAGING

摘要

An optimized pulse waveform is used to excite contrast microbubbles such that the subharmonic signal may be easily isolated for imaging. By reducing the contribution of transmitted fundamental frequency f0 within the subharmonic band, the subharmonic imaging quality is improved. This is accomplished by transmitting an optimized pulse waveform and then filtering the received signal to isolate the subharmonic signal for imaging. The optimized pulse waveform has low spectral energy within a band of frequencies centered at f0/2 and high spectral energy within another band of frequencies centered at f0, where both bands are within the transducer passband. The contrast-generated subharmonic signal is extracted by a receive filter centered at f0/2.