Objective. CT abdominal perfusion is frequently used to evaluate tumor evolution when patients are undergoing antiangiogenic
therapy. Parameters depending on longer-term dynamics of the diffusion of the contrast medium (e. g.
permeability) could help assessing the treatment efficacy. To this end, dynamic image sequences are obtained while patients
breath freely. Prior to any analysis, one needs to compensate the respiratory motion. The goal of our study is
to optimize the CT reconstruction parameters (filter of reconstruction, thickness of image volumes) for our registration
method. We also aim at proposing relevant criteria allowing to quantify the registration quality. Methods. Registration is
computed in 4 steps: z-global rigid registration, local refinements with multiresolution blockmatching, regularization and
warping. Two new criteria are defined to evaluate the quality of registration: one for spatial evaluation and the other for
temporal evaluation. Results. The two measures decrease after registration (58% and 10% average decrease for the best
reconstruction parameters for the spatial and temporal criteria respectively) which is consistent with visual inspection of
the images. They are therefore used to determine the best combination of reconstruction parameters.