Efficient Transmit Delay Calculation in Ultrasound Coherent Plane-Wave Compound Imaging for Curved Array Transducers

Abstract

The recently introduced plane-wave compounding method based on multiple plane-wave excitation has enabled several new applications due to its high frame rate (>1000 Hz). In this paper, a new efficient transmit delay calculation method in plane-wave compound imaging for a curved array transducer is presented. In the proposed method, the transmit delay is only calculated for a steering angle of 0° and is shifted along the element of the transducer to obtain other transmit delays for different steering angles. To evaluate the performance of the proposed method, the computational complexity was measured for various transmission conditions. For the number of elements and plane-wave excitations of 128 and 65, respectively, the number of operations was substantially decreased in the proposed method compared with the conventional method (256 vs. 8320). The benefits of the proposed method were demonstrated with phantom and in vivo experiments, where coherent plane-wave compounding with 65 excitations provided larger CR and CNR values compared to nine excitations (−22.5 dB and 2.7 vs. −11.3 dB and 1.9, respectively). These results indicate the proposed method can effectively reduce the computational complexity for plane-wave compound imaging in curved array transducers.

Quantitative assessment of ensemble coherency in contrast‐free ultrasound microvasculature imaging

“…High frame rate imaging was performed using in‐system plane wave imaging implementation that automatically calculated the delay for angular steering of the transmitted plane waves, with a maximum angle of and a step size of 23‐26 . For the curvilinear probe, the radius of the curvature of the aperture was accounted for in plane wave delay calculations 27 . The ultrasound transmit and receive sequences involved 128 and 64 probe elements, respectively.…”

“… 23 , 24 , 25 , 26 For the curvilinear probe, the radius of the curvature of the aperture was accounted for in plane wave delay calculations. 27 The ultrasound transmit and receive sequences involved 128 and 64 probe elements, respectively. The receive sequence was repeated twice for each half of the transducer to emulate a 128 element receive aperture.…”