A dual-excitation approach for dynamic fluorescence molecular tomography

Fluorescence molecular tomography (FMT) can quantify fluorophore concentration based on the static assumption that the fluorophore concentration is time invariant during the multi-projection acquisition process. However, when investigating the kinetic behaviors of fluorophores, especially when the change of fluorophore concentration is fast, the static assumption would provide inadequate temporal information and bring noise in the reconstruction results. In this study, we propose a dual-excitation approach for dynamic FMT to effectively image the time-varying fluorophores. Dual-excitation with the same source-detector pair is employed to collect two fluorescence measurements with a fixed time interval. Then, linear extrapolation is applied to the two measurements to compensate the measurement data from the adjacent source-detector pair. With the compensated measurement data over 360 degrees projections, a sequence of fluorophore concentration images can be reconstructed with Tikhonov regularization. Numerical simulation results demonstrate the feasibility of the proposed approach in improving the temporal resolution and reducing the noise in dynamic FMT.