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: CoPLA coating material for interventional multi-spectral MPI.
Written by: F. Griese, A. Dreyer, J. Salamon, H. Ittrich, and T. Knopp
in: <em>World Molecular Imaging Congress (WMIC) 2018</em>. (2018).
Volume: Number:
on pages:
how published:

Note: inproceedings

Abstract: Background: Magnetic Particle Imaging (MPI) is a quantitative imaging modality that resolves super-paramagnetic iron oxide particles (SPIO) with non-linear magnetization by means of static and oscillating magnetic fields. In addition, MPI provides a high temporal resolution, a fully 3D spatial resolution and a high sensitivity for resolving the distribution of SPIOs1,2. With these characteristics MPI has been successfully used for localizing and quantifying SPIO labeled cells in mice over long periods3. Further, multi-spectral MPI has been deployed for cardio-vascular interventions where blood pool tracers can be discriminated from coated instruments4. Usually the SPIOs are available in a fluid form. But coating instruments with liquid SPIOs can be challenging since the particles have to be fixated to the solid material of the instruments. Furthermore as the nanoparticles are imobilized within the PLA, the magnetic relaxation mechanisms are only given by the Neel rotation while the brownian rotation motion is inhibited. Purpose: The purpose of this study is to investigate long-term stable imobilized MPI sensitive nanoparticles embedded within 3D printable and easy to process PLA suitable for instrument coating and multi-spectral MPI imaging. Methods: We embedded imobilized Co particles d= 12nm inside a synthetic polymere structure of polylactic acid (PLA) and coated the tip of 4 catheters of type GLIDECATH Cobra 3 (C3) Fr. 5 0.97mm with different masses of Co of 0.13mg, 0.18mg, 0.34mg and 0.45mg. The catheters were simply coated by dipping them into the melt of CoPLA. As liquid tracer perimag (micromod) in concentration c=2.5mmol/L was filled inside a straight vessel phantom with inner diameter of 2.5mm and the coated catheters were placed inside the vessel phantom. During the real-time measurements with the Bruker Preclinical MPI scanner the catheters were pulled back manually. Results: The tip of catheter 4 (red) with the highest Co mass of 0.45mg was clearly separable from the surrounding perimag (green) and the manual pullback movement as seen in Fig. 1 can be identified in the temporal highly resolved images. The tips of catheters 1-3 were also discernable within the solution of perimag but the contrast was weaker linear corresponding to their lower mass. The measurements were repeated after three months and they show no differences in signal strength and separability. Discussion & Conclusion: The instrumentation coating with CoPLA has shown to be a long-term stable, easy to apply and allows for multi-spectral MPI. It was clearly separable with high contrast from the liquid used blood pool tracer and could be identified in real-time measurements. The use of CoPLA as a embeddable tracer material is not limited to instruments and could be build inside all desirable forms such as fiducials due to its ability to be 3D printable.