4D POSITRON EMISSION TOMOGRAPHY IMAGE RECONSTRUCTION BASED ON BIOMECHANICAL RESPIRATORY MOTION

International audienceRespiratory-induced organ motion is a technical challenge tonuclear imaging and to particle therapy dose calculations forlung cancer treatment in particular. Internal organ tissue dis-placements and deformations induced by breathing need to betaken into account when calculating Monte Carlo dose distri-butions or when performing tomographic reconstructions forPET imaging. This paper proposes a method to reconstructPET activities over tetrahedral meshes which are deformedbased on biomechanical patient specific model of the respi-ratory system to tackle the non reproductibility of the breath-ing. We also describe the adaptation of the popular List-ModeMaximum Likelihood Estimation (LM-MLEM) reconstruc-tion algorithm to motion estimation model using the finite el-ement method (FEM). Our simulations demonstrate the accu-racy of the proposed 4D LM-MLEM reconstruction algorithmbased on biomechanical model and its capability to correctmotion artifacts due to the breathing