Crosstalk analysis of comb detection for measuring shear wave propagation

Abstract

Applications, such as shear wave elastography and Doppler imaging, require high frame rates. Plane wave compounding (PWC) is widely used for these applications. Comb detection was proposed to combine the high frame rate of PWC and the high signal quality of focused beam scanning. Comb detection transmits multiple focused beams simultaneously to increase the frame rate. These comb beams are scanned laterally to cover the whole region-of-interest. The simultaneous multiple transmission of focused beams causes crosstalk between neighboring beams. Transmit crosstalk is related to the pressure field of transmit beams, and receive crosstalk is determined by the beam profile of receive beamforming. In this study, we varied f-number (F/N) and apodization window and measured their effects on crosstalk based on the pressure field and an arterial wall simulation using Field II. For transmit design, transmit apodization with a Hamming window significantly reduced crosstalk compared to a rectangular window and transmit F/N had little impact on the crosstalk. Regarding receive beamforming, a Hamming window led to lower crosstalk than the rectangular window and F/N from 1 to 5 suppressed crosstalk to below 30 dB. The effects of crosstalk in shear wave motion data from phantom experiments were also analyzed. Comb detection showed less motion artifact than PWC in phantom experiments.