Optical Tomography Imaging Based on Higher Order Born Approximation of Diffuse Photon Density Waves

Abstract

In this paper, we introduce a tomographical system suitable for imaging absorbers in strongly scattering media using a single light source-detector pair. Their reflective alignment would make it possible to implement both source and detector into a compact scan-head. Suitable probes would be soft tissue, some strongly scattering biological probes, or translucent technical materials, for example. An intensity-modulation technique is utilized to take advantage of the amplitude and delay alterations between the source and the detector. The propagation of the photons is modeled by the Helmholtz equation and then appropriate inverse calculations of several measurements reveal the distribution of the absorption coefficient inside the investigated volume. Therefore a reconstruction algorithm employing a Born approximation of higher order and a Tikhonov-regularization scheme were used to solve the deduced ill-posed and underdetermined system of equations. In this paper, we present results of simulations as well as of measurements.