Iterative method for bioluminescence tomography based on the radiative transport equation

Bioluminescence tomography (BLT) is a new molecular imaging modality, which helps study cancer and other diseases, develop drugs, and so on. This technology localizes and quantifies a bioluminescent source inside a living transgenic mouse, and is very useful in many biomedical applications. In this paper, we propose a novel algorithm based on the radiative transport equation to reconstruct the bioluminescence source distribution from data measured on the external surface of a mouse. Our approach transforms the transport equation into an integral equation of the second kind, and establishes a linear system to link the measured photon fluence rate with the unknown light source variables. A regularization measure is taken to overcome the ill-posedness of the inverse problem. Then, an iterative optimization technique with a simple constrain is employed to compute the desirable solution. The physical phantom experiments have been performed to demonstrate the feasibility of the reconstruction method, and evaluate its performance in terms of source location and power estimation.