The reconstruction algorithm for endoscopic diffuse optical tomography based on effective detection area

To reduce the cost of near-infrared endoscopic image equipment and the reconstruction time, a measurement method based on the effective detection area is proposed and the corresponding algorithm which simultaneously reconstructs the absorption coefficient and the reduced scattering coefficient is developed. First, the effective detection area is investigated with the Monte Carlo simulation. Secondly, the image reconstruction algorithm based on the effective detection area is studied. The Jacobin matrix is built by combining the adjoint method with the modified Generalized Pulse Spectrum Technique and calibrated by the maximum of its absolute value. The Generalized Minimal Residual Krylov method is used to obtain the iterative update factor. Finally, the impact of the number of measured points in the effective detection area on the reconstructed results is discussed, and the robustness of the algorithm to noise and cross-talk are verified by the simulated test data. The results show that the reconstructed algorithm based on the effective detection area has equivalent accuracy to the traditional ones. The fidelity of reconstructed absorption and reduced scattering coefficients can be 80%, respectively. The scales and positions of the reconstructed lesions are both correspond to the true and the reconstruction time is reduced by half. The optimal number of sources and detectors is 16 depending on the scale of the simulation model. The detection using the effective detection area and the developed reconstruction algorithm will promote the development of diffuse optical tomography which is applied to cervical and other tubular organs.