Durán, Daniel H.Daniel H.DuránScheffler, KonradKonradSchefflerMöddel, MartinMartinMöddelKnopp, TobiasTobiasKnopp2025-04-112025-04-112025-03-14International Journal on Magnetic Particle Imaging 11 (1, Suppl 1): 2503015 (2025)https://hdl.handle.net/11420/55327Image reconstruction in Magnetic Particle Imaging (MPI) typically requires a system matrix, obtained through a time-consuming calibration process. To bypass this, various model-based approaches have been explored. Recent work demonstrated successful reconstruction by adapting a Chebyshev approach with Tikhonov-regularized least squares (LS) under an equilibrium model with anisotropy. In this study, we introduce an efficient evaluation of the forward and adjoint operators for the anisotropy model, enabling the use of iterative solvers and alternative regularization methods for image reconstruction.en2365-903320251, Suppl 1Infinite Science Publishinghttps://creativecommons.org/licenses/by/4.0/Technology::621: Applied Physics::621.3: Electrical Engineering, Electronic EngineeringComputer Science, Information and General Works::004: Computer SciencesNatural Sciences and Mathematics::519: Applied Mathematics, ProbabilitiesJournal Articlehttps://doi.org/10.15480/882.1507110.18416/IJMPI.2025.250301510.15480/882.15071Journal Article