Multi-wavelength diffusive optical tomography using independent component analysis and time reversal algorithms

Optical imaging using independent component analysis (OPTICA) and time reversal optical tomography (TROT) approaches are used to detect, locate, and obtain cross-section images of two tumor pieces inside a model human breast assembled using ex vivo human breast tissues and configured as a semi-cylindrical slab of uniform thickness. The experimental arrangement realized a multi-source probing scheme to illuminate an end face (source plane) of the slab sample using 750 nm, 800 nm and 830 nm beams of laser light. A multi-detector signal acquisition scheme measured transmitted light intensity distribution on the other end face (detection plane). This combined multi-source probing and multi-detector sensing approach culminated in multiple spatial and angular views of the sample necessary for target localization. The perturbations in light intensity distribution in the detection plane were analyzed using both the OPTICA and the TROT approaches to obtain locations of the tumor pieces. A back-projection technique with OPTICA provided cross-section images and estimates of cross section of the targets within the sample. The estimated locations and dimensions of targets are in good agreement with the results of a corroborating magnetic resonance imaging experiment and known values.