4D POSITRON EMISSION TOMOGRAPHY IMAGE RECONSTRUCTION BASED ON BIOMECHANICAL RESPIRATORY MOTION
Résumé
Respiratory-induced organ motion is a technical challenge to
nuclear imaging and to particle therapy dose calculations for
lung cancer treatment in particular. Internal organ tissue dis-
placements and deformations induced by breathing need to be
taken into account when calculating Monte Carlo dose distri-
butions or when performing tomographic reconstructions for
PET imaging. This paper proposes a method to reconstruct
PET activities over tetrahedral meshes which are deformed
based 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-Mode
Maximum 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 algorithm
based on biomechanical model and its capability to correct
motion artifacts due to the breathing.