@article{MaierWigstromHofmannetal., author = {Maier, Andreas and Wigstrom, Lars and Hofmann, Hannes G and Hornegger, Joachim and Zhu, Lei and Strobel, Norbert and Fahrig, Rebecca}, title = {Three-dimensional anisotropic adaptive filtering of projection data for noise reduction in cone beam CT}, series = {Medical Physic}, volume = {38}, journal = {Medical Physic}, number = {11}, doi = {10.1118/1.3633901}, pages = {5896 -- 5909}, abstract = {Purpose: The combination of quickly rotating C-arm gantry with digital flat panel has enabled the acquisition of three-dimensional data (3D) in the interventional suite. However, image quality is still somewhat limited since the hardware has not been optimized for CT imaging. Adaptive anisotropic filtering has the ability to improve image quality by reducing the noise level and therewith the radiation dose without introducing noticeable blurring. By applying the filtering prior to 3D reconstruction, noise-induced streak artifacts are reduced as compared to processing in the image domain. Methods: 3D anisotropic adaptive filtering was used to process an ensemble of 2D x-ray views acquired along a circular trajectory around an object. After arranging the input data into a 3D space (2D projections + angle), the orientation of structures was estimated using a set of differently oriented filters. The resulting tensor representation of local orientation was utilized to control the anisotropic filtering. Low-pass filtering is applied only along structures to maintain high spatial frequency components perpendicular to these. The evaluation of the proposed algorithm includes numerical simulations, phantom experiments, and in-vivo data which were acquired using an AXIOM Artis dTA C-arm system (Siemens AG, Healthcare Sector, Forchheim, Germany). Spatial resolution and noise levels were compared with and without adaptive filtering. A human observer study was carried out to evaluate low-contrast detectability. Results: The adaptive anisotropic filtering algorithm was found to significantly improve low-contrast detectability by reducing the noise level by half (reduction of the standard deviation in certain areas from 74 to 30 HU). Virtually no degradation of high contrast spatial resolution was observed in the modulation transfer function (MTF) analysis. Although the algorithm is computationally intensive, hardware acceleration using Nvidia's CUDA Interface provided an 8.9-fold speed-up of the processing (from 1336 to 150 s). Conclusions: Adaptive anisotropic filtering has the potential to substantially improve image quality and/or reduce the radiation dose required for obtaining 3D image data using cone beam CT.}, language = {en} } @inproceedings{RoserZhongBirkholdetal., author = {Roser, Philipp and Zhong, Xia and Birkhold, Annette and Preuhs, Alexander and Syben, Christopher and Hoppe, Elisabeth and Strobel, Norbert and Kowarschik, Markus and Fahrig, Rebecca and Maier, Andreas}, title = {Simultaneous estimation of X-ray back-scatter and forward-scatter using multi-task learning}, series = {Medical Image Computing and Computer Assisted Intervention-MICCAI 2020: 23rd International Conference, Lima, Peru, October 4-8, 2020, Proceedings, Part II 23}, booktitle = {Medical Image Computing and Computer Assisted Intervention-MICCAI 2020: 23rd International Conference, Lima, Peru, October 4-8, 2020, Proceedings, Part II 23}, publisher = {Springer International Publishing}, doi = {10.1007/978-3-030-59713-9_20}, pages = {199 -- 208}, language = {en} } @inproceedings{ZhongRoserBayeretal., author = {Zhong, Xia and Roser, Philipp and Bayer, Siming and Ravikumar, Nishant and Strobel, Norbert and Birkhold, Annette and Horz, Tim and Kowarschik, Markus and Fahrig, Rebecca and Maier, Andreas}, title = {Pediatric Patient Surface Model Atlas Generation and X-Ray Skin Dose Estimation}, series = {Bildverarbeitung f{\"u}r die Medizin 2019: Algorithmen - Systeme - Anwendungen. Proceedings des Workshops vom 17. bis 19. M{\"a}rz 2019 in L{\"u}beck}, booktitle = {Bildverarbeitung f{\"u}r die Medizin 2019: Algorithmen - Systeme - Anwendungen. Proceedings des Workshops vom 17. bis 19. M{\"a}rz 2019 in L{\"u}beck}, publisher = {Springer Fachmedien}, address = {Wiesbaden}, doi = {10.1007/978-3-658-25326-4_27}, pages = {122 -- 127}, language = {en} } @inproceedings{RoserBirkholdPreuhsetal., author = {Roser, Philipp and Birkhold, Annette and Preuhs, Alexander and Syben, Christopher and Strobel, Norbert and Kowarschik, Markus and Fahrig, Rebecca and Maier, Andreas}, title = {Deep scatter splines: Learning-based medical X-ray scatter estimation using B-splines}, series = {The 6th International Conference on Image Formation in X-Ray Computed Tompgraphy}, booktitle = {The 6th International Conference on Image Formation in X-Ray Computed Tompgraphy}, language = {en} } @inproceedings{ShettyBirkholdStrobeletal., author = {Shetty, Karthik and Birkhold, Annette and Strobel, Norbert and Egger, Bernhard and Jaganathan, Srikrishna and Kowarschik, Markus and Maier, Andreas}, title = {Deep Learning Compatible Differentiable X-ray Projections for Inverse Rendering}, series = {Bildverarbeitung f{\"u}r die Medizin 2021: Proceedings, German Workshop on Medical Image Computing, Regensburg, March 7-9}, booktitle = {Bildverarbeitung f{\"u}r die Medizin 2021: Proceedings, German Workshop on Medical Image Computing, Regensburg, March 7-9}, publisher = {Springer Fachmedien}, address = {Wiesbaden}, pages = {290 -- 295}, language = {en} } @inproceedings{ShettyBirkholdJaganathanetal., author = {Shetty, Karthik and Birkhold, Annette and Jaganathan, Srikrishna and Strobel, Norbert and Kowarschik, Markus and Maier, Andreas and Egger, Bernhard}, title = {PLIKS - A Pseudo-Linear Inverse Kinematic Solver for3D Human Body Estimation}, series = {Proceedings of the IEEE/CVF Conference on Computer Vision and Pattern Recognition}, booktitle = {Proceedings of the IEEE/CVF Conference on Computer Vision and Pattern Recognition}, pages = {574 -- 584}, language = {en} } @article{MaulRoserBirkholdetal., author = {Maul, Noah and Roser, Philipp and Birkhold, Annette and Kowarschik, Markus and Zhong, Xia and Strobel, Norbert and Maier, Andreas}, title = {Learning-based occupational x-ray scatter estimation}, series = {Physics in Medicine and Biology}, volume = {67}, journal = {Physics in Medicine and Biology}, number = {7}, doi = {10.1088/1361-6560/ac58dc}, language = {en} } @article{ZhongAmrehnRavikumaretal., author = {Zhong, Xia and Amrehn, Mario and Ravikumar, Nishant and Chen, Shuqing and Strobel, Norbert and Birkhold, Annette and Kowarschik, Markus and Fahrig, Rebecca and Maier, Andreas}, title = {Deep action learning enables robust 3D segmentation of body organs in various CT and MRI images}, series = {Scientific Reports}, volume = {11}, journal = {Scientific Reports}, number = {1}, doi = {10.1038/s41598-021-82370-6}, language = {en} } @article{RoserBirkholdPreuhsetal., author = {Roser, Philipp and Birkhold, Annette and Preuhs, Alexander and Stimpel, Bernhard and Syben, Christopher and Strobel, Norbert and Kowarschik, Markus and Fahrig, Rebecca and Maier, Andreas}, title = {Fully-automatic CT data preparation for interventional X-ray skin dose simulation}, series = {Bildverarbeitung f{\"u}r die Medizin 2020: Algorithmen - Systeme - Anwendungen. Proceedings des Workshops vom 15. bis 17. M{\"a}rz 2020 in Berlin}, journal = {Bildverarbeitung f{\"u}r die Medizin 2020: Algorithmen - Systeme - Anwendungen. Proceedings des Workshops vom 15. bis 17. M{\"a}rz 2020 in Berlin}, publisher = {Springer Fachmedien}, address = {Wiesbaden}, doi = {10.1007/978-3-658-29267-6_26}, pages = {125 -- 130}, language = {en} } @article{RoserBirkholdPreuhsetal., author = {Roser, Philipp and Birkhold, Annette and Preuhs, Alexander and Ochs, Philipp and Stepina, Elizaveta and Strobel, Norbert and Kowarschik, Markus and Fahrig, Rebecca and Maier, Andreas}, title = {XDose: toward online cross-validation of experimental and computational X-ray dose estimation}, series = {International Journal of Computer Assisted Radiology and Surgery}, volume = {16}, journal = {International Journal of Computer Assisted Radiology and Surgery}, number = {2}, doi = {10.1007/s11548-020-02298-6}, language = {en} }