Prof. Marc Kachelrieß Profile

Prof. Marc Kachelrieß

Professor of X-Ray Imaging and CT at Deutsches Krebsforschungszentrum (DKFZ)

SPIE Involvement:

Conference Program Committee | Author

Publications (56)

Proceedings Article | 1 April 2024 Presentation + Paper

May denoising remove structures? How to reconstruct invariances of CT denoising algorithms

Elias Eulig, Joscha Maier, Björn Ommer, Marc Kachelrieß

Proceedings Volume 12925, 1292506 (2024) https://doi.org/10.1117/12.3005952

KEYWORDS: Deep learning, Denoising, Reconstruction algorithms, Computed tomography, X-ray computed tomography, Medical imaging, Image denoising

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Proceedings Article | 1 April 2024 Poster + Paper

Deep grid inpainting for photon-counting CT detectors

Jan Magonov, Joscha Maier, Eric Fournié, Johan Sunnegårdh, Karl Stierstorfer, Marc Kachelrieß

Proceedings Volume 12925, 129252S (2024) https://doi.org/10.1117/12.3006725

KEYWORDS: Image restoration, X-ray computed tomography, Interpolation, Image quality, Computed tomography, Deep learning, Medical imaging

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Proceedings Article | 1 April 2024 Poster + Paper

Real-time dynamic 3D CBCT reconstruction from two projections using latent information of past time steps

Cem Daloglu, Tim Vöth, Marc Kachelrieß

Proceedings Volume 12925, 129253H (2024) https://doi.org/10.1117/12.3006169

KEYWORDS: 3D modeling, 3D projection, Image restoration, Education and training, X-rays, Reconstruction algorithms, Data modeling, Cone beam computed tomography, X-ray imaging, Performance modeling

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Proceedings Article | 18 October 2022 Open Access

Learning CT scatter estimation without labeled data: a feasibility study

Joscha Maier, Luca Jordan, Elias Eulig, Fabian Jäger, Stefan Sawall, Michael Knaup, Marc Kachelrieß

Proceedings Volume 12304, 123042Z (2022) https://doi.org/10.1117/12.2646588

KEYWORDS: Artificial neural networks, Compton scattering, CT reconstruction, Computed tomography, X-ray computed tomography

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Proceedings Article | 18 October 2022 Open Access

Reconstructing invariances of CT image denoising networks using invertible neural networks

Elias Eulig, Björn Ommer, Marc Kachelrieß

Proceedings Volume 12304, 123040S (2022) https://doi.org/10.1117/12.2647170

KEYWORDS: Denoising, Computed tomography, Neural networks, Image denoising, Reconstruction algorithms, Image quality

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Proceedings Article | 18 October 2022 Open Access

Detruncation of clinical CT scans using a discrete algebraic reconstruction technique prior

Achim Byl, Michael Knaup, Magdalena Rafecas, Christoph Hoeschen, Marc Kachelrieß

Proceedings Volume 12304, 123041M (2022) https://doi.org/10.1117/12.2646885

KEYWORDS: Computed tomography, Reconstruction algorithms, CT reconstruction, Algorithm development, Image restoration, Scanners

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Proceedings Article | 18 October 2022 Open Access

3D reconstruction of stents and guidewires in an anthropomorphic phantom from three x-ray projections

Tim Vöth, Thomas König, Elias Eulig, Michael Knaup, Veit Wiesmann, Klaus Hörndler, Marc Kachelrieß

Proceedings Volume 12304, 1230411 (2022) https://doi.org/10.1117/12.2646406

KEYWORDS: X-rays, Reconstruction algorithms, X-ray imaging, Fluoroscopy, Image segmentation, 3D acquisition, 3D image processing, Computed tomography, Image-guided intervention

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Proceedings Article | 18 October 2022 Open Access

Deep scatter estimation for coarse anti-scatter grids as used in photon-counting CT

Julien Erath, Jan Magonov, Joscha Maier, Eric Fournié, Martin Petersilka, Karl Stierstorfer, Marc Kachelrieß

Proceedings Volume 12304, 123040J (2022) https://doi.org/10.1117/12.2646580

KEYWORDS: Computed tomography, Monte Carlo methods, Neural networks, Reconstruction algorithms, Scattering compensation, Photon counting

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Proceedings Article | 18 October 2022 Open Access

Organ-specific vs. patient risk-specific tube current modulation in thorax CT scans covering the female breast

Laura Klein, Lucia Enzmann, Achim Byl, Chang Liu, Stefan Sawall, Andreas Maier, Joscha Maier, Michael Lell, Marc Kachelrieß

Proceedings Volume 12304, 123041I (2022) https://doi.org/10.1117/12.2646582

KEYWORDS: Breast, Modulation, Computed tomography, X-ray computed tomography, Tissues, Monte Carlo methods, Image segmentation, Image quality, Cancer

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Proceedings Article | 18 October 2022 Open Access

Deep learning-based detector row upsampling for clinical spiral CT

Jan Magonov, Julien Erath, Joscha Maier, Eric Fournié, Karl Stierstorfer, Marc Kachelrieß

Proceedings Volume 12304, 1230407 (2022) https://doi.org/10.1117/12.2647101

KEYWORDS: Computed tomography, Collimation, X-ray computed tomography, Network architectures

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Proceedings Article | 4 April 2022 Presentation + Paper

Real-time 3D reconstruction of multiple guidewires at dose values of conventional 2D fluoroscopy

Tim Vöth, Thomas König, Elias Eulig, Michael Knaup, Klaus Hörndler, Marc Kachelrieß

Proceedings Volume 12031, 120311M (2022) https://doi.org/10.1117/12.2606579

KEYWORDS: X-rays, Reconstruction algorithms, Fluoroscopy, X-ray imaging, 3D image reconstruction, 3D acquisition, 3D scanning, Image-guided intervention

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Proceedings Article | 4 April 2022 Presentation + Paper

DeepRAR: a CNN-based approach for CT and CBCT ring artifact reduction

Philip Trapp, Carlo Amato, Stefan Sawall, Marc Kachelrieß, Tim Vöth

Proceedings Volume 12031, 120311D (2022) https://doi.org/10.1117/12.2612667

KEYWORDS: Computed tomography, Sensors, X-ray computed tomography, Signal detection, Data corrections, 3D image reconstruction, Photon counting, Neural networks, Network architectures, Head

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Proceedings Article | 16 March 2020 Presentation + Paper

Deep learning-aided CBCT image reconstruction of interventional material from four x-ray projections

Elias Eulig, Joscha Maier, N. Robert Bennett, Michael Knaup, Klaus Hörndler, Adam Wang, Marc Kachelrieß

Proceedings Volume 11312, 113121L (2020) https://doi.org/10.1117/12.2548662

KEYWORDS: X-rays, X-ray imaging, Tomography, Fluoroscopy, Convolutional neural networks, Data acquisition, 3D modeling, Computer programming, Image guided radiation therapy, Medical image reconstruction, Computed tomography, X-ray computed tomography

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Proceedings Article | 28 May 2019 Paper

Learned digital subtraction angiography (Deep DSA): method and application to lower extremities

Elias Eulig, Joscha Maier, Michael Knaup, Thomas Koenig, Klaus Hörndler, Marc Kachelrieß

Proceedings Volume 11072, 1107223 (2019) https://doi.org/10.1117/12.2534740

KEYWORDS: Angiography, X-ray imaging, X-rays, Data acquisition, Image enhancement, Visualization, Convolutional neural networks, Fluoroscopy, Data modeling, Digital imaging

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Proceedings Article | 28 May 2019 Paper

Artifacts reduction method in 4DCBCT based on a weighted demons registration framework

Shaohua Zhi, Bangliang Jiang, Marc Kachelrieß, Xuanqin Mou

Proceedings Volume 11072, 110722R (2019) https://doi.org/10.1117/12.2534489

KEYWORDS: Image registration, Computed tomography, Optical flow, Image processing, Image quality, Cancer, Image restoration, Optimization (mathematics)

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Proceedings Article | 28 May 2019 Paper

On the impact of input feature selection in deep scatter estimation for positron emission tomography

Yannick Berker, Marc Kachelrieß

Proceedings Volume 11072, 110720S (2019) https://doi.org/10.1117/12.2534281

KEYWORDS: Positron emission tomography, Convolution, Feature selection, Photons, Convolutional neural networks, Monte Carlo methods, X-ray computed tomography, Computer simulations, Compton scattering, Scattering compensation, Quantitative analysis

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Proceedings Article | 7 March 2019 Presentation + Paper

Towards large-area photon-counting detectors for spectral x-ray imaging

Thomas Thuering, Spyridon Gkoumas, Pietro Zambon, Peter Trueb, Michael Rissi, Flavio Di Prima, Tilman Donath, Stefan Sawall, Carlo Amato, Marc Kachelrieß, Christian Broennimann

Proceedings Volume 10948, 1094817 (2019) https://doi.org/10.1117/12.2507190

KEYWORDS: Sensors, X-ray imaging, Absorption, X-rays, Prototyping, Photodetectors, Bone, Iodine, Radiography, Medical imaging applications

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Proceedings Article | 1 March 2019 Presentation + Paper

Forward and cross-scatter estimation in dual source CT using the deep scatter estimation (DSE)

Tim Vöth, Joscha Maier, Julien Erath, Marc Kachelrieß

Proceedings Volume 10948, 109480P (2019) https://doi.org/10.1117/12.2512718

KEYWORDS: X-ray computed tomography, Convolutional neural networks, Monte Carlo methods, Computed tomography, X-ray imaging, Computer simulations, Neural networks, X-rays, Scattering compensation, Scattering, Dual energy imaging, Machine learning

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Proceedings Article | 1 March 2019 Paper

Image-based noise reduction for material decomposition in dual or multi energy computed tomography

Mahmut Özdemir, Sabrina Dorn, Francesco Pisana, Monika Uhrig, Heinz-Peter Schlemmer, Marc Kachelrieß

Proceedings Volume 10948, 109482U (2019) https://doi.org/10.1117/12.2513388

KEYWORDS: Denoising, Image filtering, Computed tomography, X-ray computed tomography

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Proceedings Article | 1 March 2019 Paper

Focal spot deconvolution using convolutional neural networks

Jan Kuntz, Joscha Maier, Marc Kachelrieß, Stefan Sawall

Proceedings Volume 10948, 109480Q (2019) https://doi.org/10.1117/12.2513400

KEYWORDS: Spatial resolution, Point spread functions, Image resolution, X-ray imaging, Sensors, Deconvolution, Convolutional neural networks, X-rays, X-ray computed tomography, Image quality

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Proceedings Article | 9 March 2018 Presentation + Paper

Stack transition artifact removal for cardiac CT using patch-based similarities

Sergej Lebedev, Eric Fournie, Karl Stierstorfer, Marc Kachelrieß

Proceedings Volume 10573, 105731X (2018) https://doi.org/10.1117/12.2293232

KEYWORDS: Image registration, Heart, Computed tomography, Image quality, Cardiac imaging, Image enhancement

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Proceedings Article | 9 March 2018 Paper

A count rate-dependent method for spectral distortion correction in photon counting CT

Jannis Dickmann, Joscha Maier, Stefan Sawall, Thomas Thüring, Spyridon Gkoumas, Christian Brönnimann, Marc Kachelriess

Proceedings Volume 10573, 1057311 (2018) https://doi.org/10.1117/12.2292194

KEYWORDS: Iodine, Calibration, Distortion, Computed tomography, Signal to noise ratio, Photon counting, Spectral calibration

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Proceedings Article | 9 March 2018 Paper

Organ-specific context-sensitive CT image reconstruction and display

Sabrina Dorn, Shuqing Chen, Stefan Sawall, David Simons, Matthias May, Joscha Maier, Michael Knaup, Heinz-Peter Schlemmer, Andreas Maier, Micheal Lell, Marc Kachelrieß

Proceedings Volume 10573, 1057326 (2018) https://doi.org/10.1117/12.2291897

KEYWORDS: Image segmentation, Spatial resolution, Computed tomography, Reconstruction algorithms, CT reconstruction

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Proceedings Article | 9 March 2018 Presentation + Paper

Deep scatter estimation (DSE): feasibility of using a deep convolutional neural network for real-time x-ray scatter prediction in cone-beam CT

Joscha Maier, Yannick Berker, Stefan Sawall, Marc Kachelrieß

Proceedings Volume 10573, 105731L (2018) https://doi.org/10.1117/12.2292919

KEYWORDS: Monte Carlo methods, X-rays, Data modeling, CT reconstruction, Convolutional neural networks, X-ray detectors, Sensors, Data acquisition, Scattering, X-ray computed tomography

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Proceedings Article | 9 March 2018 Paper

Influence of data completion on scatter artifact correction for truncated cone-beam CT data

Nadine Waltrich, Stefan Sawall, Joscha Maier, Jan Kuntz, Kai Stannigel, Kai Lindenberg, Marc Kachelrieß

Proceedings Volume 10573, 1057349 (2018) https://doi.org/10.1117/12.2292198

KEYWORDS: Monte Carlo methods, Image quality, Tissues, X-ray computed tomography, Signal attenuation, Reconstruction algorithms, Head, Sensors, Image restoration, X-ray imaging

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Proceedings Article | 9 March 2017 Presentation + Paper

High quality high spatial resolution functional classification in low dose dynamic CT perfusion using singular value decomposition (SVD) and k-means clustering

Francesco Pisana, Thomas Henzler, Stefan Schönberg, Ernst Klotz, Bernhard Schmidt, Marc Kachelrieß

Proceedings Volume 10132, 101320M (2017) https://doi.org/10.1117/12.2251161

KEYWORDS: Functional imaging, Computed tomography, Spatial resolution, Visualization, Liver, Brain, Signal attenuation, Brain mapping, Blood, Blood circulation

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Dynamic CT perfusion acquisitions are intrinsically high-dose examinations, due to repeated scanning. To keep radiation dose under control, relatively noisy images are acquired. Noise is then further enhanced during the extraction of functional parameters from the post-processing of the time attenuation curves of the voxels (TACs) and normally some smoothing filter needs to be employed to better visualize any perfusion abnormality, but sacrificing spatial resolution. In this study we propose a new method to detect perfusion abnormalities keeping both high spatial resolution and high CNR. To do this we first perform the singular value decomposition (SVD) of the original noisy spatial temporal data matrix to extract basis functions of the TACs. Then we iteratively cluster the voxels based on a smoothed version of the three most significant singular vectors. Finally, we create high spatial resolution 3D volumes where to each voxel is assigned a distance from the centroid of each cluster, showing how functionally similar each voxel is compared to the others. The method was tested on three noisy clinical datasets: one brain perfusion case with an occlusion in the left internal carotid, one healthy brain perfusion case, and one liver case with an enhancing lesion. Our method successfully detected all perfusion abnormalities with higher spatial precision when compared to the functional maps obtained with a commercially available software. We conclude this method might be employed to have a rapid qualitative indication of functional abnormalities in low dose dynamic CT perfusion datasets. The method seems to be very robust with respect to both spatial and temporal noise and does not require any special a priori assumption. While being more robust respect to noise and with higher spatial resolution and CNR when compared to the functional maps, our method is not quantitative and a potential usage in clinical routine could be as a second reader to assist in the maps evaluation, or to guide a dataset smoothing before the modeling part.

Proceedings Article | 9 March 2017 Presentation + Paper

MLAA-based RF surface coil attenuation estimation in hybrid PET/MR imaging

Thorsten Heußer, Christopher Rank, Martin Freitag, Marc Kachelrieß

Proceedings Volume 10132, 101321F (2017) https://doi.org/10.1117/12.2255658

KEYWORDS: Signal attenuation, Positron emission tomography, Reconstruction algorithms, Magnetic resonance imaging, Cancer, Radiology, Medical research

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Proceedings Article | 9 March 2017 Paper

Motion vector field upsampling for improved 4D cone-beam CT motion compensation of the thorax

Sebastian Sauppe, Christopher Rank, Marcus Brehm, Pascal Paysan, Dieter Seghers, Marc Kachelrieß

Proceedings Volume 10132, 101322E (2017) https://doi.org/10.1117/12.2255603

KEYWORDS: Computed tomography, CT reconstruction, Temporal resolution, Data acquisition, Image guided radiation therapy, Motion estimation, Image restoration, Reconstruction algorithms, Cones, Image registration, Motion measurement, Medical imaging

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Proceedings Article | 9 March 2017 Presentation + Paper

Reanimating patients: cardio-respiratory CT and MR motion phantoms based on clinical CT patient data

Johannes Mayer, Sebastian Sauppe, Christopher Rank, Stefan Sawall, Marc Kachelrieß

Proceedings Volume 10132, 101321V (2017) https://doi.org/10.1117/12.2255628

KEYWORDS: Algorithm development, Reconstruction algorithms, Motion measurement, Computed tomography, Image restoration, Motion analysis, Temporal resolution, Motion estimation, Cones, Optical simulations, Image registration, Optical spheres, Radiotherapy

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Proceedings Article | 25 March 2016 Paper

Reduction of motion artifacts in cardiac CT based on partial angle reconstructions from short scan data

Juliane Hahn, Herbert Bruder, Thomas Allmendinger, Karl Stierstorfer, Thomas Flohr, Marc Kachelriess

Proceedings Volume 9783, 97831A (2016) https://doi.org/10.1117/12.2216181

KEYWORDS: Reconstruction algorithms, Computed tomography, Motion estimation, Temporal resolution, Motion measurement, Motion models, Image quality, Heart, Data acquisition, Arteries, Image segmentation, Beam propagation method

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Proceedings Article | 22 March 2016 Paper

Shifted detector super short scan reconstruction for the rotate-plus-shift trajectories and its application to C-arm CT systems

Jan Kuntz, Michael Knaup, Christof Fleischmann, Marc Kachelrieß

Proceedings Volume 9783, 97830I (2016) https://doi.org/10.1117/12.2216639

KEYWORDS: Sensors, Computed tomography, Imaging systems, Reconstruction algorithms, Data acquisition, Control systems, Cones, Algorithm development, Computer simulations, Calibration, Fluctuations and noise, X-ray computed tomography, Detection and tracking algorithms, Image quality, X-rays

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Proceedings Article | 22 March 2016 Paper

Five-dimensional motion compensation for respiratory and cardiac motion with cone-beam CT of the thorax region

Sebastian Sauppe, Andreas Hahn, Marcus Brehm, Pascal Paysan, Dieter Seghers, Marc Kachelrieß

Proceedings Volume 9783, 97830H (2016) https://doi.org/10.1117/12.2216266

KEYWORDS: Motion estimation, Heart, Reconstruction algorithms, 3D image processing, Image restoration, Sensors, Image quality, X-rays, Radiotherapy, X-ray imaging

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Proceedings Article | 22 March 2016 Paper

Automatic intrinsic cardiac and respiratory gating from cone-beam CT scans of the thorax region

Andreas Hahn, Sebastian Sauppe, Michael Lell, Marc Kachelrieß

Proceedings Volume 9783, 97830S (2016) https://doi.org/10.1117/12.2216224

KEYWORDS: Computed tomography, Computer simulations, Digital filtering, Data acquisition, Bone, Heart, Bandpass filters, Algorithm development, Calibration, Detection and tracking algorithms, Sensors, Beam propagation method

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Proceedings Article | 22 March 2016 Paper

Low dose CT perfusion using k-means clustering

Francesco Pisana, Thomas Henzler, Stefan Schönberg, Ernst Klotz, Bernhard Schmidt, Marc Kachelrieß

Proceedings Volume 9783, 97833M (2016) https://doi.org/10.1117/12.2214709

KEYWORDS: Computed tomography, Spatial resolution, Brain, Tissues, Image quality, Tumors, Denoising, Blood, Targeting Task Performance metric, Brain mapping

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Proceedings Article | 18 March 2015 Paper

Optimization and image quality assessment of the alpha-image reconstruction algorithm: iterative reconstruction with well-defined image quality metrics

Sergej Lebedev, Stefan Sawall, Stefan Kuchenbecker, Sebastian Faby, Michael Knaup, Marc Kachelrieß

Proceedings Volume 9412, 94120O (2015) https://doi.org/10.1117/12.2082043

KEYWORDS: Image quality, Reconstruction algorithms, Modulation transfer functions, Spatial resolution, Neodymium, Tissues, Optimization (mathematics), Image restoration, Computed tomography, Diagnostics

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Proceedings Article | 18 March 2015 Paper

The rotate-plus-shift C-arm trajectory: complete CT data with limited angular rotation

Ludwig Ritschl, Jan Kuntz, Marc Kachelrieß

Proceedings Volume 9412, 941221 (2015) https://doi.org/10.1117/12.2081925

KEYWORDS: Sensors, Fluctuations and noise, Stereoscopy, Image quality, Data acquisition, Computed tomography, Prototyping, 3D image processing, Physics, Cancer

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Proceedings Article | 18 March 2015 Paper

Multi-dimensional tensor-based adaptive filter (TBAF) for low dose x-ray CT

Michael Knaup, Sergej Lebedev, Stefan Sawall, Marc Kachelrieß

Proceedings Volume 9412, 94123P (2015) https://doi.org/10.1117/12.2081910

KEYWORDS: Image filtering, Digital filtering, Gaussian filters, CT reconstruction, X-rays, X-ray computed tomography, Image restoration, Linear filtering, X-ray imaging, Physics

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Proceedings Article | 18 March 2015 Paper

A photon counting detector model based on increment matrices to simulate statistically correct detector signals

Sebastian Faby, Joscha Maier, David Simons, Heinz-Peter Schlemmer, Michael Lell, Marc Kachelrieß

Proceedings Volume 9412, 94124Z (2015) https://doi.org/10.1117/12.2081751

KEYWORDS: Sensors, Signal detection, Photon counting, Matrices, Luminescence, Compton scattering, Data modeling, Single photon, Photoelectric effect, Statistical modeling

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Proceedings Article | 18 March 2015 Paper

Respiratory motion compensation for simultaneous PET/MR based on a 3D-2D registration of strongly undersampled radial MR data: a simulation study

Christopher Rank, Thorsten Heußer, Barbara Flach, Marcus Brehm, Marc Kachelrieß

Proceedings Volume 9412, 941218 (2015) https://doi.org/10.1117/12.2080998

KEYWORDS: Positron emission tomography, Magnetic resonance imaging, 3D image reconstruction, Reconstruction algorithms, Motion measurement, Image registration, 3D image processing, 3D modeling, Lung, Abdomen

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Proceedings Article | 19 March 2014 Paper

Removing blooming artifacts with binarized deconvolution in cardiac CT

Christian Hofmann, Michael Knaup, Marc Kachelrieß

Proceedings Volume 9033, 90330J (2014) https://doi.org/10.1117/12.2036559

KEYWORDS: Reconstruction algorithms, Deconvolution, Computed tomography, Scanners, Spatial resolution, Point spread functions, Signal attenuation, Computer simulations, Image processing, Sensors

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Proceedings Article | 19 March 2014 Paper

A new approach to regularized iterative CT image reconstruction

Christian Hofmann, Michael Knaup, Marc Kachelrieß

Proceedings Volume 9033, 90330R (2014) https://doi.org/10.1117/12.2042992

KEYWORDS: Reconstruction algorithms, Spatial resolution, Image resolution, Sensors, Image restoration, Scanners, CT reconstruction, Neodymium, Denoising, Data acquisition

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Proceedings Article | 19 March 2014 Paper

CT calibration and dose minimization in image-based material decomposition with energy-selective detectors

Sebastian Faby, Stefan Kuchenbecker, David Simons, Heinz-Peter Schlemmer, Michael Lell, Marc Kachelrieß

Proceedings Volume 9033, 903318 (2014) https://doi.org/10.1117/12.2042877

KEYWORDS: Sensors, Iodine, Calibration, Photon counting, Dual energy imaging, Computed tomography, Denoising, X-rays, Computer simulations, X-ray detectors

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Proceedings Article | 6 March 2013 Paper

Modelling and simulation of a respiratory motion monitor using a continuous wave Doppler radar in near field

Florian Pfanner, Thomas Allmendinger, Thomas Flohr, Marc Kachelrieß

Proceedings Volume 8668, 866837 (2013) https://doi.org/10.1117/12.2007716

KEYWORDS: Antennas, Radar, Motion measurement, Reflectors, Wave propagation, Motion models, Near field, Computer simulations, Doppler tomography, Tissues

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Proceedings Article | 6 March 2013 Paper

Removing intra plane blurring in dental panoramas

Christian Hofmann, Michael Knaup, Marc Kachelrieß

Proceedings Volume 8668, 86682K (2013) https://doi.org/10.1117/12.2007889

KEYWORDS: Panoramic photography, Sensors, Data acquisition, Fluctuations and noise, Collimation, Imaging systems, Teeth, Radiography, Head, X-ray computed tomography

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Dental imaging often requires to gather information from a curved plane that covers the upper and lower jaw. To acquire these data one may either use a CT or a DVT scan followed by extracting the desired curved plane from the volumetric CT data, or one may decide to work at much lower dose levels and acquire a panoramic radiograph, which is also known as an orthopantomogram, or short as panorama. The panorama is acquired by moving the x-ray source and detector arrangement such that the x-ray cone intersects the curved plane in a preferably perpendicular way. Due to the small size of specialized panorama x-ray detectors, that often run in the so-called time-delayed integration (TDI) mode, the cone is collimated such that it is only a few millimeters wide in the fan direction. In this situation the fan angle is much smaller than the cone angle. Assuming an imaging system based on flat detectors the panoramic imaging corresponds to digital x-ray tomosynthesis taken in a curved plane. Of course, panoramic imaging suffers from significant blurring between adjacent planes, as it is inherent to all tomosynthesis techniques. To reduce this intra plane blurring we propose an approach that uses a form filter to simultaneously acquire the data for a typical orthopantomogram and low-dose data with a significantly increased fan-angle, sufficient to perform a low-dose FDK reconstruction. The bow-tie takes care to reduce dose in that extended region to about 1% compared to the dose in the central region. The total dose remains constant. These data will be combined resulting in an orthopantomogram with improved image quality due to reduced intra plane blurring as one is able to subtract the unwanted background structures arising from off focus objects as for example the cervical vertebrae. We conducted simulations to validate our approach. For that we use a volumetric CT data set of a patient's head from which we generated rawdata. The simulation results show that with our approach panoramic imaging with a flat detector offers the possibility to improve image quality without additional costs in patient dose.

Proceedings Article | 3 March 2012 Paper

Edge-preserving metal artifact reduction

Esther Meyer, Rainer Raupach, Michael Lell, Bernhard Schmidt, Marc Kachelriess

Proceedings Volume 8313, 83133A (2012) https://doi.org/10.1117/12.906392

KEYWORDS: Metals, Computed tomography, Spine, Image segmentation, Bone, Image quality, Image filtering, Diagnostics, Linear filtering, Image processing algorithms and systems

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Proceedings Article | 17 March 2011 Paper

Improved total variation regularized image reconstruction (iTV) applied to clinical CT data

Ludwig Ritschl, Marc Kachelriess

Proceedings Volume 7961, 79612R (2011) https://doi.org/10.1117/12.878070

KEYWORDS: Reconstruction algorithms, Metals, Tomography, Image restoration, Computed tomography, Image quality, Compressed sensing, Optimization (mathematics), X-rays, CT reconstruction

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Proceedings Article | 16 March 2011 Paper

Functional phase-correlated micro-CT imaging of small rodents with low dose

Stefan Sawall, Frank Bergner, Andreas Hess, Robert Lapp, Markus Mronz, Marek Karolczak, Marc Kachelriess

Proceedings Volume 7961, 796124 (2011) https://doi.org/10.1117/12.877343

KEYWORDS: Heart, Image quality, Reconstruction algorithms, Image restoration, Image quality standards, Beam propagation method, Sensors, Electrocardiography, Lung, Scanners

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Proceedings Article | 16 March 2011 Paper

Quantification of temporal resolution and its reliability in the context of TRI-PICCS and dual source CT

Clemens Maaß, Marc Kachelrieß

Proceedings Volume 7961, 79611M (2011) https://doi.org/10.1117/12.877976

KEYWORDS: Temporal resolution, Reliability, Computed tomography, Reconstruction algorithms, Motion measurement, Scanners, Medical imaging, Image quality, Image segmentation, Visualization

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Proceedings Article | 23 March 2010 Paper

A new approach to limited angle tomography using the compressed sensing framework

Ludwig Ritschl, Frank Bergner, Marc Kachelriess

Proceedings Volume 7622, 76222H (2010) https://doi.org/10.1117/12.844303

KEYWORDS: Reconstruction algorithms, Image segmentation, Image processing algorithms and systems, Compressed sensing, Computed tomography, Tomography, Data analysis, Radon transform, Algorithm development, Bone

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Proceedings Article | 22 March 2010 Paper

Material decomposition with inconsistent rays (MDIR) for cone-beam dual energy CT

Clemens Maass, Rainer Grimmer, Marc Kachelrieß

Proceedings Volume 7622, 76221X (2010) https://doi.org/10.1117/12.844546

KEYWORDS: Bone, Dual energy imaging, Computed tomography, X-ray computed tomography, Scanners, Iodine, Head, X-rays, Algorithm development, Ear

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Proceedings Article | 1 March 2008 Paper

Real-time computed tomography on the cell broadband engine processor

Olivier Bockenbach, Michael Knaup, Marc Kachelriess

Proceedings Volume 6812, 68120E (2008) https://doi.org/10.1117/12.766265

KEYWORDS: Computed tomography, Reconstruction algorithms, Surface plasmons, Sensors, Image filtering, Personal protective equipment, Computing systems, Tomography, Scanners, Image quality

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Proceedings Article | 19 March 2007 Paper

Implementation of a cone-beam backprojection algorithm on the cell broadband engine processor

Olivier Bockenbach, Michael Knaup, Marc Kachelrieß

Proceedings Volume 6510, 651056 (2007) https://doi.org/10.1117/12.709238

KEYWORDS: Field programmable gate arrays, Reconstruction algorithms, Computing systems, Sensors, Mercury, Image restoration, Image processing, Tomography, Standards development, Power supplies

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Proceedings Article | 28 February 2007 Paper

Tomographic image reconstruction using the cell broadband engine (CBE) general purpose hardware

Michael Knaup, Sven Steckmann, Olivier Bockenbach, Marc Kachelrieß

Proceedings Volume 6498, 64980P (2007) https://doi.org/10.1117/12.716500

KEYWORDS: Sensors, Image restoration, Clocks, Reconstruction algorithms, Detection and tracking algorithms, Tomography, Computing systems, Image processing, Computed tomography, CT reconstruction

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Proceedings Article | 3 July 2001 Paper

Novel approximate approach for high-quality image reconstruction in helical cone-beam CT at arbitrary pitch

Stefan Schaller, Karl Stierstorfer, Herbert Bruder, Marc Kachelriess, Thomas Flohr

Proceedings Volume 4322, (2001) https://doi.org/10.1117/12.431009

KEYWORDS: Sensors, Image segmentation, Reconstruction algorithms, Scanners, Image quality, Computed tomography, Image restoration, Detection and tracking algorithms, Computer simulations, Collimation

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Proceedings Article | 6 June 2000 Paper

Advanced single-slice rebinning in cone-beam spiral CT: theoretical considerations and medical applications

Marc Kachelriess, Stefan Schaller, Willi Kalender

Proceedings Volume 3979, (2000) https://doi.org/10.1117/12.387710

KEYWORDS: Reconstruction algorithms, Computed tomography, Sensors, Scanners, Image quality, Detection and tracking algorithms, Image quality standards, Gold, Lithium, Fluctuations and noise

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Proceedings Article | 6 June 2000 Paper

Performance of approximate cone-beam reconstruction in multislice computed tomography

Herbert Bruder, Marc Kachelriess, Stefan Schaller, Thomas Mertelmeier

Proceedings Volume 3979, (2000) https://doi.org/10.1117/12.387715

KEYWORDS: Sensors, Reconstruction algorithms, Detection and tracking algorithms, Image quality, Scanners, X-rays, Modulation transfer functions, Image restoration, X-ray computed tomography, Computed tomography

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