Coherent multi-probe pulse inversion harmonic imaging

Harmonic imaging is an important clinical tool thanks to its ability to enhance the quality of ultrasound images by utilizing the second harmonic component of backscattered echoes. Coherent multi-transducer ultrasound (CoMTUS) imaging enables the use of multiple arrays as one large effective aperture, yielding images with enlarged field of view, improved resolution, and higher signal-to-noise ratio. The benefits of harmonic imaging have previously been shown to extend to large-aperture systems, but translation to multi-probe systems has not been investigated.In this work, through pulse inversion (PI) sequences we demonstrated, for the first time, multi-probe harmonic imaging. This has been shown to offer improved resolution and suppressed acoustic clutter, compared to the fundamental frequency. Using a fundamental frequency of 1.5 MHz, harmonic CoMTUS achieved lateral resolution improvements of up to a factor of two compared with the fundamental. Overall, this work demonstrates that the known benefits of harmonic imaging can be extended to multi-probe systems.