Transforming Static CT in Gated PET/CT Studies to Multiple Respiratory Phases M Dawood, F Büther, N Lang, X Jiang, KP Schäfers Department of Nuclear Medicine, University Hospital Münster, Germany

Transforming static CT to multiple phases M. Dawood et al. Motion correction in 3d PET/CT with advanced optical flow algorithms. Submitted to ieee transactions on medical imaging. PET/CT Positron Emission Tomography / Computed Tomography

Transforming static CT to multiple phases M. Dawood et al. Motion correction in 3d PET/CT with advanced optical flow algorithms. Submitted to ieee transactions on medical imaging. PET Positron Emission Tomography β + -decay of 18 F: 18 F → 18 O + e + + ν e Pair annihilation: e + + e - → 2 γ

Transforming static CT to multiple phases M. Dawood et al. Motion correction in 3d PET/CT with advanced optical flow algorithms. Submitted to ieee transactions on medical imaging. LOR φ s Detector 2 Detector 1 s φ LOR Sinogram

Transforming static CT to multiple phases M. Dawood et al. Motion correction in 3d PET/CT with advanced optical flow algorithms. Submitted to ieee transactions on medical imaging. Reconstruction

Transforming static CT to multiple phases M. Dawood et al. Motion correction in 3d PET/CT with advanced optical flow algorithms. Submitted to ieee transactions on medical imaging. Attenuation

Transforming static CT to multiple phases M. Dawood et al. Motion correction in 3d PET/CT with advanced optical flow algorithms. Submitted to ieee transactions on medical imaging. Problem Spatial non-correspondance between PET and CT due to motion

Transforming static CT to multiple phases M. Dawood et al. Motion correction in 3d PET/CT with advanced optical flow algorithms. Submitted to ieee transactions on medical imaging. Solution Divide the PET data into respiratory phases, and transform the static CT to corresponding phases

Transforming static CT to multiple phases M. Dawood et al. Motion correction in 3d PET/CT with advanced optical flow algorithms. Submitted to ieee transactions on medical imaging. Gating …

Transforming static CT to multiple phases M. Dawood et al. Motion correction in 3d PET/CT with advanced optical flow algorithms. Submitted to ieee transactions on medical imaging. Gating: Acquiring the respiratory signal

Transforming static CT to multiple phases M. Dawood et al. Motion correction in 3d PET/CT with advanced optical flow algorithms. Submitted to ieee transactions on medical imaging. Optical Flow A method to estimate deformation between image frames Independent of the form and type of movement between the frames Non-rigid and pixel-based

Transforming static CT to multiple phases M. Dawood et al. Motion correction in 3d PET/CT with advanced optical flow algorithms. Submitted to ieee transactions on medical imaging. Combined Local/Global Minimize f LG

Transforming static CT to multiple phases M. Dawood et al. Motion correction in 3d PET/CT with advanced optical flow algorithms. Submitted to ieee transactions on medical imaging. Discontinuity Preserving Non-Quadratic Non-Quadratic approach allows better approximation than least squares Discontinuity preservation allows better estimation across organ boundaries Minimize f D

Transforming static CT to multiple phases M. Dawood et al. Motion correction in 3d PET/CT with advanced optical flow algorithms. Submitted to ieee transactions on medical imaging. Lukas/Kanade Horn/Schunck Bruhn Non-LinearDiscontinuity Preserving Result Demonstration

Transforming static CT to multiple phases M. Dawood et al. Motion correction in 3d PET/CT with advanced optical flow algorithms. Submitted to ieee transactions on medical imaging. Results: Gated data

Transforming static CT to multiple phases M. Dawood et al. Motion correction in 3d PET/CT with advanced optical flow algorithms. Submitted to ieee transactions on medical imaging. Results: Attenuation Without Motion Correction

Transforming static CT to multiple phases M. Dawood et al. Motion correction in 3d PET/CT with advanced optical flow algorithms. Submitted to ieee transactions on medical imaging. Results: Transformed Attenuation Map

Transforming static CT to multiple phases M. Dawood et al. Motion correction in 3d PET/CT with advanced optical flow algorithms. Submitted to ieee transactions on medical imaging. Results: Attenuation With Transformed Map