3-D Coherent Multi-Transducer Ultrasound Imaging with Sparse Spiral Arrays

TL;DR

This paper demonstrates a novel 3-D coherent multi-transducer ultrasound imaging system using sparse spiral arrays, significantly enhancing resolution, contrast, and target detectability while maintaining low data processing requirements.

Contribution

First implementation of 3-D CoMTUS with sparse spiral arrays, combining high-resolution imaging with low channel count and data complexity.

Findings

Up to 10 times improved spatial resolution

Contrast-to-noise ratio increased by up to 30%

Enhanced target detectability and dynamic range

Abstract

Coherent multi-transducer ultrasound (CoMTUS) creates an extended effective aperture through the coherent combination of multiple arrays, which results in images with enhanced resolution, extended field-of-view, and higher sensitivity. The subwavelength localization accuracy of the multiple transducers required to coherently beamform the data is achieved by using the echoes backscattered from targeted points. In this study, CoMTUS is implemented and demonstrated for the first time in 3-D imaging using a pair of 256-element 2-D sparse spiral arrays, which keep the channel-count low and limit the amount of data to be processed. The imaging performance of the method was investigated using both simulations and phantom tests. The feasibility of free-hand operation is also experimentally demonstrated. Results show that, in comparison to a single dense array system using the same total number of active elements, the proposed CoMTUS system improves spatial resolution (up to 10 times) in the direction where both arrays are aligned, contrast-to-noise-ratio (CNR, up to 30%), and generalized CNR (up to 11%). Overall, CoMTUS shows narrower main lobe and higher contrast-to-noise-ratio, which results in an increased dynamic range and better target detectability.