Acoustical Tomography for Absorbing Scatterers Based on the Second-Order Rytov Transform Perturbation Approximation
声衍射层析成像中吸收型散射体的Rytov二阶近似重建

In this paper, a reconstruction algorithm of acoustical tomography is presented for absorbing scatterers based on the second order Rytov transform perturbation approximation. Both the wave number and the absorbing coefficient of the scatterers are reconstructed. The reconstruction algorithm is similar to one for phase scatterers, but the computation of the direct scattering is different, because the attenuation must be calculated. A comparison of some reconstruction algorithms is also given, such as those based on the first and second order Born approximations and those based on the first and second order Rytov approximations. The results show that the algorithm based on the second order Rytov approximation has an advantage over the other three algorithms in the most cases.