Prof. Dr.-Ing. Tobias Knopp

Universitätsklinikum Hamburg-Eppendorf (UKE)
Sektion für Biomedizinische Bildgebung
Lottestraße 55
2ter Stock, Raum 209
22529 Hamburg
- Postanschrift -

Technische Universität Hamburg (TUHH)
Institut für Biomedizinische Bildgebung
Gebäude E, Raum 4.044
Am Schwarzenberg-Campus 3
21073 Hamburg

Tel.: 040 / 7410 56794
Fax: 040 / 7410 45811
E-Mail: t.knopp(at)
E-Mail: tobias.knopp(at)



  • Head of the Institute for Biomedical Imaging
  • Editor-in-chief of the International Journal on Magnetic Particle Imaging (IJMPI)

Consulting Hours

  • On appointment

Research Interests

  • Tomographic Imaging
  • Image Reconstruction
  • Signal- and Image Processing
  • Magnetic Particle Imaging

Curriculum Vitae

Tobias Knopp received his Diplom degree in computer science in 2007 and his PhD in 2010, both from the University of Lübeck with highest distinction. For his PHD on the tomographic imaging method Magnetic Particle Imaging (MPI) he was awarded with the Klee award from the DGBMT (VDE) in 2011. From 2010 until 2011 he led the MAPIT project at the University of Lübeck and published the first scientific book on MPI. In 2011 he joined Bruker Biospin to work on the first commercially available MPI system. From 2012 until 2014 he worked at Thorlabs in the field of Optical Coherence Tomography (OCT) as a software developer. In 2014 he has been appointed as Professor for experimental Biomedical Imaging at the University Medical Center Hamburg-Eppendorf and the Hamburg University of Technology.


Title: Suppression of Motion Artifacts in Multi-Patch Magnetic Particle Imaging of a Phantom with Periodic Motion.
Written by: M. Boberg, N. Gdaniec, M. Möddel, P. Szwargulski, and T. Knopp
in: <em>SIAM Conference on Imaging Science (IS22)</em>. (2022).
Volume: Number:
on pages:
how published:

Note: inproceedings, multi-patch, artifact

Abstract: Magnetic particle imaging (MPI) is a tracer based imaging technique, which determines the spatial distribution of superparamagnetic iron oxide nanoparticles with a high spatial and temporal resolution. Therefore, MPI is able to image dynamic tracer distributions like cardiac or respiratory motion in in-vivo experiments. As a matter of fact, the imaging volume covers only a few cubic centimeters due to physiological constraints. To cover larger objects a multi-patch approach is used where the imaging volume is shifted relative to the object. Since this reduces the temporal resolution, motion artifacts can occur during the measurement and reconstruction of dynamic tracer distributions. For periodic motions such as the aforementioned cardiac motion, this problem can be solved by reordering the raw measurement data. In a first step, the motion frequency is calculated by analyzing the raw data without reconstruction and without an additional navigator signal. Afterwards data snippets of the raw data corresponding to a specific motion state are rearranged into a virtual frame by using multiple repetitions of the motion state. Finally, the virtual frames can be reconstructed by standard reconstruction techniques. In our experiments, we successfully reconstructed a rotating phantom with a repetition time of 0.56 s without any motion artifacts, while a single full multi-patch measurement cycle takes at least 0.69 s.