An adaptive V-grid algorithm for diffuse optical tomography

We investigate an adaptive multigrid approach to improve the computational efficiency and the quantitative accuracy of DOT image reconstruction. The key idea is based on a locally refined grid structure for region of interest (ROI). A least squares (LS) solution is formulated for the inverse problem. A fast adaptive composite (FAC) V-grid algorithm is employed to solve the inverse problem. The same problem is also solved using a fixed fine grid and FAC 2-grid scheme for a 2-level locally refined grid. Our numerical studies demonstrate that the proposed FAC based adaptive V-grid approach provides better image quality and up to 90% reduction in computational requirements as compared to the fixed grid and at least 10% reduction as compared to FAC 2-grid algorithms.