An eigenfunction method for reconstruction of large-scale and high-contrast objects
An eigenfunction method for reconstruction of large-scale and high-contrast objects
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DOI：
10.1109/tuffc.2007.392
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发表时间：
2007-07-01
影响因子：
3.6
通讯作者：
Astheimer, Jeffrey P.
中科院分区：
文献类型：
--
作者：
Waag, Robert C.;Lin, Feng;Astheimer, Jeffrey P.
利用散射算子的特征函数，将多频逆散射方法扩展到对大尺度、高对比度目标成像。该扩展使用对散射对象的估计来形成对象的散射与由对象的估计进行的散射之间的差异。由该差值定义的散射势在声场的乘积的基础上展开。这些场由与估计相关联的散射算子的本征函数来定义。在散射体的估计是径向的情况下，用于重建散射势的表达式中的对称性大大减少了计算量。通过计算不同目标的散射，说明了重建方法适用的参数范围。将该方法应用于直径为48 mm的具有组织特性的散射体的实验数据。与在相同中心频率下使用低f数形成的传统B超相比，从测量重建的图像具有明显更高的分辨率和更少的斑点，这意味着使用扩展的方法可以清楚地显示小的、高对比度的结构。
A multiple-frequency inverse scattering method that uses eigenfunctions of a scattering operator is extended to image large-scale and high-contrast objects. The extension uses an estimate of the scattering object to form the difference between the scattering by the object and the scattering by the estimate of the object. The scattering potential defined by this difference is expanded in a basis of products of acoustic fields. These fields are defined by eigenfunctions of the scattering operator associated with the estimate. In the case of scattering objects for which the estimate is radial, symmetries in the expressions used to reconstruct the scattering potential greatly reduce the amount of computation. The range of parameters over which the reconstruction method works well is illustrated using calculated scattering by different objects. The method is applied to experimental data from a 48-mm diameter scattering object with tissue-like properties. The image reconstructed from measurements has, relative to a conventional B-scan formed using a low f-number at the same center frequency, significantly higher resolution and less speckle, implying that small, high-contrast structures can be demonstrated clearly using the extended method.