Photoacoustic tomography in absorbing acoustic media using time reversal
Photoacoustic tomography in absorbing acoustic media using time reversal
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DOI：
10.1088/0266-5611/26/11/115003
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发表时间：
2010-11-01
期刊：
影响因子：
2.1
通讯作者：
Cox, B. T.
中科院分区：
文献类型：
--
作者：
Treeby, Bradley E.;Zhang, Edward Z.;Cox, B. T.
光声图像的重建通常忽略声吸收对测量的时域信号的影响。在这里，描述了一种补偿光声层析成像中声吸收的方法。该方法是基于时间反演图像重建和吸收状态方程，分别占声吸收和色散以下的频率幂律。反问题中的吸收补偿是通过反转吸收比例系数的符号而保持等效色散参数不变来实现的。通过使用Tukey窗口在空间频率域中过滤吸收和色散项来正则化重建。这保持了滤波器通带内这些参数的正确频率依赖性。该方法适用于一维、二维和三维，适用于任意幂律吸收参数。通过数值实验验证了该方法的有效性。还提出了碳纤维体模和小鼠腹部血管的重建。当包括吸收补偿时，可以看到图像幅度和分辨率的总体改善，特别是对于更深的特征。
The reconstruction of photoacoustic images typically neglects the effect of acoustic absorption on the measured time domain signals. Here, a method to compensate for acoustic absorption in photoacoustic tomography is described. The approach is based on time-reversal image reconstruction and an absorbing equation of state which separately accounts for acoustic absorption and dispersion following a frequency power law. Absorption compensation in the inverse problem is achieved by reversing the absorption proportionality coefficient in sign but leaving the equivalent dispersion parameter unchanged. The reconstruction is regularized by filtering the absorption and dispersion terms in the spatial frequency domain using a Tukey window. This maintains the correct frequency dependence of these parameters within the filter pass band. The method is valid in one, two and three dimensions, and for arbitrary power law absorption parameters. The approach is verified through several numerical experiments. The reconstruction of a carbon fibre phantom and the vasculature in the abdomen of a mouse are also presented. When absorption compensation is included, a general improvement in the image magnitude and resolution is seen, particularly for deeper features.