Comparison of Images Produced by Diffuse Optical Tomography with Two Different Backscatter Techniques

Abstract

Currently, there are several devices have been used for diagnosis of breast cancer such as X-ray tomography ultrasound and MRI. These devices sending harmful photons to the body, costly, lack of resolution and portability. Therefore searching new methods to diagnose breast cancer are necessity. One of these methods is Diffuse Optical Tomography (DOT). In DOT study, 808 nm wavelength laser which has a high penetration to tissue is used. In in-vitro experiments, DOT measurements were acquired from a breast phantom was mixture of water and 1% Intralipid. Indocyanine green (ICG) was added to the mixture to make absorption coefficient 0.04 cm-1, similar to the breast tissue. A transparent balloon was filled Intralipid and ICG with absorption coefficient of 0.16 cm1 to mimic tumor inclusion 3D Image of breast phantoms were created by using Algebraic Reconstruction Technique (ART) and Truncated Conjugate Gradient (TCG) methods. The results obtained by the TCG algorithm are closer to the real, which is the closest of inclusion` s dimensions and contains less artifact. The system which we use consists of 2401 measurement and 2250 voxels so it is called as over-determined systems. According to findings, we inference that TCG algorithm works better than ART for over-determined system.