| Date post: | 20-Dec-2015 |
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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
M. Dawood et al. Motion correction in 3d PET/CT with advanced optical flow algorithms. Submitted to ieee transactions on medical imaging.
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/CTPositron Emission Tomography / Computed Tomography
M. Dawood et al. Motion correction in 3d PET/CT with advanced optical flow algorithms. Submitted to ieee transactions on medical imaging.
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.
PETPositron Emission Tomography
β+-decay of 18F:
18F → 18O + e+ + νe
Pair annihilation: e+ + e- → 2 γ
M. Dawood et al. Motion correction in 3d PET/CT with advanced optical flow algorithms. Submitted to ieee transactions on medical imaging.
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
M. Dawood et al. Motion correction in 3d PET/CT with advanced optical flow algorithms. Submitted to ieee transactions on medical imaging.
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
M. Dawood et al. Motion correction in 3d PET/CT with advanced optical flow algorithms. Submitted to ieee transactions on medical imaging.
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
M. Dawood et al. Motion correction in 3d PET/CT with advanced optical flow algorithms. Submitted to ieee transactions on medical imaging.
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
M. Dawood et al. Motion correction in 3d PET/CT with advanced optical flow algorithms. Submitted to ieee transactions on medical imaging.
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
M. Dawood et al. Motion correction in 3d PET/CT with advanced optical flow algorithms. Submitted to ieee transactions on medical imaging.
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
…
M. Dawood et al. Motion correction in 3d PET/CT with advanced optical flow algorithms. Submitted to ieee transactions on medical imaging.
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
M. Dawood et al. Motion correction in 3d PET/CT with advanced optical flow algorithms. Submitted to ieee transactions on medical imaging.
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
M. Dawood et al. Motion correction in 3d PET/CT with advanced optical flow algorithms. Submitted to ieee transactions on medical imaging.
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 fLG
dxdydzdtVVIIVkf TTLG )(*
2
M. Dawood et al. Motion correction in 3d PET/CT with advanced optical flow algorithms. Submitted to ieee transactions on medical imaging.
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 fD
2
222
21
12
i
ii
ss
dxdydzdtSmoothingDataf D
M. Dawood et al. Motion correction in 3d PET/CT with advanced optical flow algorithms. Submitted to ieee transactions on medical imaging.
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-Linear Discontinuity Preserving Result
Demonstration
M. Dawood et al. Motion correction in 3d PET/CT with advanced optical flow algorithms. Submitted to ieee transactions on medical imaging.
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
M. Dawood et al. Motion correction in 3d PET/CT with advanced optical flow algorithms. Submitted to ieee transactions on medical imaging.
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
M. Dawood et al. Motion correction in 3d PET/CT with advanced optical flow algorithms. Submitted to ieee transactions on medical imaging.
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
M. Dawood et al. Motion correction in 3d PET/CT with advanced optical flow algorithms. Submitted to ieee transactions on medical imaging.
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
