Abstract : This study investigates the potential retention of iodide in the stomach, for a better understanding of the iodide biodistribution in the body and more precisely of its potential antiseptic role. To that end, we will study the uptake of the 99m Tc-pertechnetate (an iodide ana-log) within the murine stomach observed thanks to a SPECT camera. The temporal evolution of the uptake is analysed thanks to a dedicated multi-compartment model. The addressed challenges consist in 1) estimating the time-activity curves for the different compartments, and 2) identifying the model parameters. Real experiments on different subjects demonstrate a quite good coherence of the computed parameters, and the computed parameter values suggested that there is some iodide retention in the stomach wall.