Symmetry prior for epipolar consistency

Preuhs A, Maier A, Manhart M, Kowarschik M, Hoppe E, Fotouhi J, Navab N, Unberath M (2019)

Publication Type: Journal article

Publication year: 2019


DOI: 10.1007/s11548-019-02027-8


Purpose: For a perfectly plane symmetric object, we can find two views—mirrored at the plane of symmetry—that will yield the exact same image of that object. In consequence, having one image of a plane symmetric object and a calibrated camera, we automatically have a second, virtual image of that object if the 3-D location of the symmetry plane is known. Methods: We propose a method for estimating the symmetry plane from a set of projection images as the solution of a consistency maximization based on epipolar consistency. With the known symmetry plane, we can exploit symmetry to estimate in-plane motion by introducing the X-trajectory that can be acquired with a conventional short-scan trajectory by simply tilting the acquisition plane relative to the plane of symmetry. Results: We inspect the symmetry plane estimation on a real scan of an anthropomorphic human head phantom and show the robustness using a synthetic dataset. Further, we demonstrate the advantage of the proposed method for estimating in-plane motion using the acquired projection data. Conclusion: Symmetry breakers in the human body are widely used for the detection of tumors or strokes. We provide a fast estimation of the symmetry plane, robust to outliers, by computing it directly from a set of projections. Further, by coupling the symmetry prior with epipolar consistency, we overcome inherent limitations in the estimation of in-plane motion.

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Preuhs, A., Maier, A., Manhart, M., Kowarschik, M., Hoppe, E., Fotouhi, J.,... Unberath, M. (2019). Symmetry prior for epipolar consistency. International Journal of Computer Assisted Radiology and Surgery.


Preuhs, Alexander, et al. "Symmetry prior for epipolar consistency." International Journal of Computer Assisted Radiology and Surgery (2019).

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