<title>Near-infrared optical tomography of scattering cylindrical phantoms using time-resolved detection</title>

Abstract

A near-infrared optical tomograph has been developed to obtain 3-dimensional images of scattering phantoms with optical properties similar to those of biological tissues. This experimental setup uses a femtosecond laser and a synchroscan streak camera. Thanks to three stepping motors, the phantom to be imaged is scanned in a parallel-beam mode. The time resolved detection of scattered photons is performed in the transmission mode, for different phantom positions obtained by two translations and one rotation stages. Regarding the data processing, we have developed a nonlinear image reconstruction algorithm based on the Newton-Raphson iterative method. It executes absorption and scattering mapping on the basis of characteristic data extracted from the recorded temporal point spread function of light transmitted through the studied object, such as the mean flight time of photon, the related variance or the integral intensity. First, 2D images using absolute or differential imaging schemes have been obtained for different scattering cylindrical phantoms possessing one or two more absorbing and/or more scattering inclusions. Reconstructed images have been compared to simulated and expected values. The results demonstrate that this system is a reliable and valuable platform for research on time-resolved optical tomography.

Diffuse optical mammotomography: state-of-the-art and prospects

“…The detailed description of a singlechannel streak-camera intended for DOT is presented, e.g., in Refs. [5,232]. Figure 5 schematically illustrates the principle of its operation.…”