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.Comment: 10 pages, 6 figure