Research project

Consistency Conditions for Artifact Reduction in Cone-beam CT

Most of the current artifact reduction methods in flat- panel detector computed tomography (FDCT) rely either on heuristics, prior information, additional sensors, or iterative procedures. However, an entire family of artifact reduction methods has found only little application in current FDCT systems so far. The theoretical model of geometry and physics in CT, as well as FDCT, imposes constraints on the projection images. It is known that data consistency conditions describe mathematical redundancies in the projection data which go back to the fact that each projection is composed of line integrals passing through the same object, merely from different directions. If these redundancies are violated, e.g. by a limited FOV or due to motion of the object during the acquisition of the individual projections, data consistency conditions are typically no longer fulfilled. Data consistency conditions in CT have been investigated, especially for parallel-beam geometries for about 25 years. It has been shown that data consistency conditions offer very attractive solutions to a variety of problems, including motion estimation and correction but also the extrapolation of missing data. However, they still lack application for real systems and operate on ideal, often noise-free phantom simulations.
The goal of this project is to extend existing data consistency conditions, which can be practically used for FDCT to remedy intrinsic weaknesses of FDCT imaging, most importantly motion and truncation. Our goal is the practical applicability on clinical data.

Project manager:
Prof. Dr.-Ing. habil. Andreas Maier

Project participants:
André Aichert, M. Sc.

Duration: 1.11.2015 - 1.11.2018

Sponsored by:
Deutsche Forschungsgemeinschaft

Contact:
Aichert, André
Phone +49 9131 85 28977, Fax +49 9131 85 27270, E-Mail: andre.aichert@fau.de

Publications

Aichert, André ; Wang, Jian ; Schaffert, Roman ; Dörfler, Arnd ; Hornegger, Joachim ; Maier, Andreas: Epipolar Consistency in Fluoroscopy for Image-Based Tracking. In: Xianghua Xie ; Mark W. Jones ; Gary K. L. Tam (Ed.) : Proceedings of the British Machine Vision Conference 2015 (26th British Machine Vision Conference (BMVC 2015) Swansea, UK Sept 7-10 2015). Swansea, UK : BMVA Press, 2015, pp 86. - ISBN 1-901725-53-7

Aichert, André ; Berger, Martin ; Wang, Jian ; Maass, Nicole ; Doerfler, Arnd ; Hornegger, Joachim ; Maier, Andreas: Epipolar Consistency in Transmission Imaging. In: IEEE Transactions on Medical Imaging 34 (2015), No. 10, pp 1-15
[doi>10.1109/TMI.2015.2426417]

Grulich, Tobias ; Holub, Wolfgang ; Haßler, Ulf ; Aichert, André ; Maier, Andreas: Geometric Adjustment of X-ray Tomosynthesis. In: King, Michael (Ed.) : Fully Three-Dimensional Image Reconstruction in Radiology and Nuclear Medicine (The 13th International Meeting on Fully Three-Dimensional Image Reconstruction in Radiology and Nuclear Medicine Newport, Rhode Island, USA 31.05). 2015, pp 468-470.

Pohlmann, Marcel ; Berger, Martin ; Maier, Andreas ; Hornegger, Joachim ; Fahrig, Rebecca: Estimation of missing fan-beam projections using frequency consistency conditions. In: Noo, Frederic (Ed.) : Proceedings of the third international conference on image formation in x-ray computed tomography (The third international conference on image formation in x-ray computed tomography Salt Lake City, UT, USA 22-25.06.2014). 2014, pp 203-207.

Berger, Martin ; Maier, Andreas ; Xia, Yan ; Hornegger, Joachim ; Fahrig, Rebecca: Motion Compensated Fan-Beam CT by Enforcing Fourier Properties of the Sinogram. In: Noo, Frederic (Ed.) : Proceedings of the third international conference on image formation in x-ray computed tomography (The third international conference on image formation in x-ray computed tomography Salt Lake City, UT, USA 22-25.06.2014). 2014, pp 329-332.

Xia, Yan ; Bauer, Sebastian ; Maier, Andreas ; Berger, Martin ; Hornegger, Joachim: Patient-bounded Extrapolation for 3D Region of Interest Reconstruction in C-arm CT. In: Frederic Noo, University of Utah (Ed.) : Proceedings of the third international conference on image formation in x-ray computed tomography (The third international conference on image formation in x-ray computed tomography Salt Lake City, UT, USA 22-25.06.2014). 2014, pp 414-417.

Aichert, André ; Maass, Nicole ; Deuerling-Zheng, Yu ; Berger, Martin ; Manhart, Michael ; Hornegger, Joachim ; Maier, Andreas ; Doerfler, Arnd: Redundancies in X-ray images due to the epipolar geometry for transmission imaging. In: Noo, Frederic (Ed.) : Proceedings of the third international conference on image formation in x-ray computed tomography (The third international conference on image formation in x-ray computed tomography Salt Lake City, UT, USA 22-25.06.2014). 2014, pp 333-337.

Hoffmann, Mathis ; Würfl, Tobias ; Maaß, Nicole ; Dennerlein, Frank ; Aichert, André ; Maier, Andreas: Empirical Scatter Correction using the Epipolar Consistency Condition. In: Frederic Noo (Ed.) : Proceedings of the Fifth International Conference on Image Formation in X-Ray Computed Tomography (CT-Meeting) (Fifth International Conference on Image Formation in X-Ray Computed Tomography (CT-Meeting) Salt Lake City, USA 20.05.2018). 2018, pp 193-197.

Würfl, Tobias ; Maaß, Nicole ; Dennerlein, Frank ; Aichert, André ; Maier, Andreas: Physical Constraints for Beam Hardening Reduction using Polynomial Models. In: Frederic Noo (Ed.) : Proceedings of the Fifth International Conference on Image Formation in X-Ray Computed Tomography (CT-Meeting) (Fifth International Conference on Image Formation in X-Ray Computed Tomography (CT-Meeting) Salt Lake City, USA 20.05.2018). 2018, pp 356-359.

Unberath, Mathias ; Aichert, André ; Achenbach, Stephan ; Maier, Andreas: Consistency-based Respiratory Motion Estimation in Rotational Angiography. In: Medical Physics (2017)
[doi>10.1002/mp.12021]

Berger, Martin ; Xia, Yan ; Aichinger, Wolfgang ; Mentl, Katrin ; Unberath, Mathias ; Aichert, André ; Riess, Christian ; Hornegger, Joachim ; Fahrig, Rebecca ; Maier, Andreas: Motion Compensation for Cone-Beam CT Using Fourier Consistency Conditions. In: Physics in Medicine and Biology 62 (2017), No. 17, pp 7181-7215

Felsner, Lina ; Aichert, André ; Unberath, Mathias ; Maier, Andreas: Motion Estimation in Rotational Angiography with alpha–Expansion Moves. In: Lars R Furenlid (Ed.) : 2017 IEEE Nuclear Science Symposium and Medical Imaging Conference (2017 IEEE Nuclear Science Symposium and Medical Imaging Conference Atlanta 26.10). 2017, pp 1-3.

Aichert, André ; Breininger, Katharina ; Köhler, Thomas ; Maier, Andreas: Efficient Epipolar Consistency. In: Kachelrieß, Marc (Ed.) : Proceedings of the 4th CT Meeting (4th International Conference on Image Formation in X-Ray Computed Tomography Bamberg, Germany July 2016). 2016, pp 383-386. (Proceedings of the 4th CT Meeting)