Abstract：The aim of this work is to explore the feasibility of a largescale elastography with the existing methods, and the impact of some factors such as focal configuration and detection position, on the estimation of local shear wave speeds under the same acoustic radiation excitation. Simulation program Field II and finite element methods were used for the simulation of acoustic radiation force and tissue response, then a crosscorrelation based method was used for the estimation of local shear wave speed. Results showed that with the improvement of detection sensitivity, it was feasible for two or three excitation impulses to complete a shear wave speed image. The estimated shear wave speeds calculated with the existing methods were closely related with the spatial location of the detecting point; the difference was 12.7% between the shear wave speeds measured at superficial locations and at focal depth. The imaging area was enlarged with the increase of fnumber (focal depth/aperture size), however, the accuracy of shear wave speed estimation was reduced in the meantime. Thus, a modified algorithm was presented in the paper. After modification, the local shear wave speed is closer to the theoretical value; in the case of fnumber was 1.3, the rootmeansquare error was reduced from 3.2% to 0.6%. It is demonstrated that the existing excitation of acoustic radiation force and the modified estimation method of shear wave speed can be used in largescale elastographies.
宋珂 林江莉#* 陈科#. 激励声束聚焦形状对剪切波速度估计的影响[J]. 中国生物医学工程学报, 2014, 33(3): 257-265.
SONG Ke LIN JiangLi#* CHEN Ke#. The Impact of Focal Configuration of Excitation Beam on Shear Wave Speed Estimation#br#. journal1, 2014, 33(3): 257-265.
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