Impact of microwave pulses on thermoacoustic imaging applications

Thermoacoustic imaging is a promising modality for breast cancer detection. Acoustic signals generated by tumor targets with different sizes subject to microwave pulses with various widths and waveforms are analytically studied in this letter. Time- and frequency-domain profiles of the acoustic signals are achieved. Some key parameters of the acoustic signals, including peak value and peak-to-peak time interval of the time-domain acoustic pressure and frequency of the global peak and magnitude ratio of the second highest peak to the global peak of the frequency-domain pressure, are discussed. Impact of pulse width on acoustic signal peak-to-peak interval and image spatial resolution is developed. Square pulse is demonstrated to be superior in acquiring higher image resolution and signal-to-noise ratio. This study is helpful to optimizing the microwave pulse, selecting acoustic transducer, and evaluating image resolution.