Fluorescence Image Reconstruction for Optical Tomography Based on Transient Radiation Transfer Equation

Image reconstruction is a bottleneck problem that impedes real time application of optical tomography technology. In this paper, we propose a novel fluorescence optical tomography method with a fast yet accurate algorithm for 3D image reconstruction. This imaging method is demonstrated using radiation transfer modeling based design. First the transport of ultrafast laser radiation governed by radiation transfer equation in participating media is simulated. Then the transient fluorescence field is obtained by solving the same radiation transfer equation in which the quantum yield of fluorescence is added to correlate the absorbed laser radiation with fluorescence emission intensity. Finally, 3D images are reconstructed using the temporal signals of fluorescence at detectors around the boundary of targeted tissues. We use the early time of fluorescence flight and the maximum fluorescence intensity to directly reconstruct the 3D images. Two new concepts, i.e., the photon migration statistic property and the solid geometric correlation property, are introduced for signal and image processing, respectively. The image reconstruction in this new method is very fast and does not require any inverse optimization. The accurate and efficient image and location of a 2.4×2.4×2.4mm3 tumor embedded at two different locations inside a 20×20×20mm3 rectangular tissue are demonstrated.