Frequency-modulated magneto-acoustic detection and imaging

Abstract

Magneto-acoustic (MA) tomography combines near-field RF and ultrasound for the goal of a safe, high-resolution, high-contrast bimodal imaging technique. Coherency between RF excitation and the resulting ultrasound generation through Lorentz force interactions is established. This allows for continuous-wave (CW) imaging techniques to replace conventional pulsed-based approaches, easing system design and improving signal-to-noise ratio (SNR) while reducing the peak-toaverage excitation power ratio, for the same averaging time, sensitivity and gain. This is the first successful demonstration of MA detection using step frequency CW (SFCW) as well as frequency-modulated CW (FMCW) approaches with up to 36 dB SNR improvement. © The Institution of Engineering and Technology 2014.