Thomas Koehler

Rudolf Diesel Industry Fellow

Philips Research Laboratories

Digital Imaging

Franz Pfeiffer and Ernst Rummeny

Focus Group
Phase Contrast Computed Tomography

Short CV

Thomas Koehler studied physics at the Christian-Albrechts-University in Kiel from 1989 to 1994. Immediately after the diploma he started to work at the Philips Research Laboratories in Hamburg on the inverse problem of electro- and magnetocardiography, resulting in a Ph.D. thesis, which was finished in 1998. Since 1998, Thomas Koehler has been working on several projects in the area of inverse problems for different applications, namely computed tomography (CT), diffuse optical tomography (DOT), transmission electron microscopy (TEM), and differential phase contrast imaging (DPCI). His primary focus has been the development of reconstruction algorithms for CT and adjacent topics. Major contributions in the field of CT are in the area of approximate and exact reconstructions algorithms for helical cone-beam CT, where he covered the mathematics of reconstruction, the practical aspects arising in clinical applications, and the implementation on dedicated hardware. Furthermore, he contributed to the field of iterative reconstruction, and he is currently working together with the Department of Radiology at TUM on the forthcoming generation of iterative reconstruction algorithms for CT. During the last few years, he has gained interest in the emerging field of DPCI, where he has worked on both projection imaging as well as on tomographic imaging.


Research Interests

  • Tomographic imaging
  • Inverse problems
  • Computed tomography
  • X-ray imaging
  • Phase contrast x-ray imaging
  • Medical imaging

Selected Publications

  • Schirra, C. O.; Roessl, E.; Koehler, T.; Brendel, B.; Thran, A.; Pan, D.; Anastasio, M. A.; Proksa, R.: Statistical Reconstruction of Material Decomposed Data in Spectral CT. IEEE Transactions on Medical Imaging 32 (7), 2013, 1249-1257 more… BibTeX Full text ( DOI )
  • Köhler, Thomas; Jürgen Engel, Klaus; Roessl, Ewald: Noise properties of grating-based x-ray phase contrast computed tomography. Med. Phys. 38 (S1), 2011, S106 more… BibTeX Full text ( DOI )
  • Köhler, Thomas; Brendel, Bernhard; Roessl, Ewald: Iterative reconstruction for differential phase contrast imaging using spherically symmetric basis functions. Med. Phys. 38 (8), 2011, 4542 more… BibTeX Full text ( DOI )
  • Pfeiffer, F.; David, C.; Bunk, O.; Donath, T.; Bech, M.; Le Duc, G.; Bravin, A.; Cloetens, P.: Region-of-Interest Tomography for Grating-Based X-Ray Differential Phase-Contrast Imaging. Phys. Rev. Lett. 101 (16), 2008 more… BibTeX Full text ( DOI )
  • Ziegler, A.; Köhler, Th.; Proksa, R.: Noise and resolution in images reconstructed with FBP and OSC algorithms for CT. Med. Phys. 34 (2), 2007, 585 more… BibTeX Full text ( DOI )