相位环形统计矢量对提高全聚焦成像质量的影响

Enhancing effect of phase circular statistics vector for improvement imaging quality of ultrasonic total focusing method

为进一步提高超声全聚焦的成像质量,提出一种基于相位环形统计矢量的全聚焦成像方法。首先,在全聚焦实施过程中提取全矩阵数据中信号的相位信息。然后,将同一聚焦像素点的相位视作环形分布的统计样本,通过饱和状态加权统计构建由幅值和相位分布共同决定的相位环形统计矢量。最后,将相位环形统计矢量的模等效为全聚焦图像的幅值。结果表明,该成像算法既能够通过放大相位分布对信号幅值的贡献提高信噪比,又能够通过减小声束宽度有效提高横向分辨率。相比于相位相干加权算法SCF和CCF,基于相位环形统计矢量的算法对相位偏差的容忍度更高。

For further improving the quality of Total Focusing Method(TFM)imaging,an ultrasonic TFM based on Phase Circular Statistics Vector(PCSV)has been presented.Firstly,the information of the signal phases of the Full Matrix Capture(FMC)aperture data is extracted in the TFM implement processes.The phases of the same focusing pixel were regarded as the samples of the circular statistics.Then the PCSVs determined by the signal amplitudes and phases were acquired by using the operation of saturation weighted statistics.Finally,the magnitudes of the PCSV were equivalent to the amplitudes of the TFM image.The results showed that the TFM-PCSV was capable of improving SNR by amplifying the contribution of phase information.Also,the method could improve the lateral resolution by enhancing aperture beam directivity.Compared to the phase coherence weighted algorithm SCF and CCF,the TFM-PCSV has higher tolerance to the error of phases.