Acoustical diffraction tomography in a finite form based on the Rytov transform.

A new reconstruction algorithm in a finite form based on the Rytov transform is presented for acoustical diffraction tomography. Applying the Rytov transform to the governing differential wave equation necessarily introduces the so-called generalized scattering. Our analysis shows that the generalized scattered wave is asymptotically equivalent to the physically scattered wave, and also satisfies the Sommerfeld radiation condition in the far field. Using the method of formal parameter expansion, we further find that all other terms in the expansion of the object function vanish except the first- and second-order ones, and thus reach a finite form solution to the diffraction tomography. Our computer simulation confirms the effectiveness of the algorithm in the case of the scattering objects with cylindrical symmetry, also shows its limitations when it applies to the strong scattering.