Deep high resolution 4D ultrafast ultrasound imaging with 2D matrix arrays*

As a non-invasive, non-irradiant and accessible modality, ultrafast ultrasound is more and more favored. Particularly, its role in cancer diagnosis is crucial since a cheap and highly effective imaging modality will allow early and wide screening of patients and considerably enhance the survival rates. In this work, we propose a novel probe design to provide unprecedented spatial resolution in ultrasound imaging, from three spatial dimensions up to 4D (x,y,z,t) when imaging media on ultrafast time scales.

We designed a 1024-transducer array of 64x16 elements, and central frequency 2.5MHz. This rectangular geometry enhances the field of view while still allowing steering capability in both directions. A high-end 1024-channel ultrasound scanner, was used to drive our probe. Importantly, we transmitted and received 2D plane waves with the whole aperture and thus achieved ultrafast imaging rates up to 1kHz at 10 cm depth.

On commercial phantoms, we were able to demonstrate high resolution of 0.5mm at 16 cm depth and contrast-enhanced approaches allow a +9dB gain on microbubbles imaging. Parallel reconstruction algorithms achieved processing times as low as 1ms, being thus real-time. Such capabilities will soon allow soon unveil ultrafast phenomena occurring deep inside the human body.