Fourier-based 3D Ultrafast Ultrasound Imaging with Diverging Waves: In Vitro Experiment Validation
Résumé
Background, Motivation and ObjectiveUltrafast imaging based on diverging wave (DW) is an active area of research in ultrasound sectorial acquisition because of its capacity of reaching high frame rate. Recently, we have introduced a 3D Fourier-based formalism for the reconstruction of 3D sectorial images with DW insonifications and validated with numerical simulations [Zhang et al. IUS 2016]. The proposed method can provide comparable image quality as DAS but with a much lower computational complexity. This study aims to experimentally verify these theoretical conclusions in vitro.Statement of Contribution/MethodsA 32-by-32 matrix array centered at 3 MHz with a 0.3 mm pitch (Vermon, Tours, France) interfaced with 4 Verasonics systems was used to transmit 3D DW sequences and acquire the reflected echoes. The experiment was performed on an ultrasound phantom (CIRS model: 054GS). Each DW was emitted from a virtual source point with an angular aperture of 90º and a sub-aperture of 16×16 elements as in [Provost et al. 2014]. The received rawdata was post-processed in Matlab using the proposed Fourier-based algorithm in [Zhang et al., IUS 2016].Results/DiscussionFigure1 displays the orthogonal slices along x-z direction of the volumetric images reconstructed from the proposed Fourier-based method using 1 and 81 DWs, respectively. This result shows, visually, the image quality (i.e. both lateral resolution and image contrast) can be improved with 81 DW for compounding, which is consistent with what have beenobserved from simulations [Zhang et al., IUS 2016].