Dr.-Ing. Matthias Gräser

Universitätsklinikum Hamburg-Eppendorf (UKE)
Sektion für Biomedizinische Bildgebung
Lottestraße 55
2ter Stock, Raum 212
22529 Hamburg

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

Tel.: 040 / 7410 25812
E-Mail: matthias.graeser(at)tuhh.de
E-Mail: ma.graeser(at)uke.de

Research Interests

  • Magnetic Particle Imaging
  • Low Noise Electronics
  • Inductive Sensors
  • Passive Electrical Devices

Curriculum Vitae

Matthias Gräser submitted his Dr.-Ing. thesis in january 2016 at the institute of medical engineering (IMT) at the university of Lübeck and is now working as a Research Scientist at the institute for biomedical imaging (IBI) at the technical university in Hamburg, Germany.  Here he develops concepts for Magnetic-Particle-Imaging (MPI) devices. His main aim is to improve the sensitivity of the imageing devices and improve resolution and application possibilities of MPI technology.

In 2011 Matthias Gräser started to work at the IMT as a Research Associate in the Magnetic Particle Imaging Technology (MAPIT) project. In this project he devolped the analog signal chains for a rabbit sized field free line imager. Additionally he developed a two-dimensional Magnetic-Particle-Spectrometer. This device can apply various field sequences and measure the particle response with a very high signal-to-noise ratio (SNR).

The dynamic behaviour of magnetic nanoparticles is still not fully understood. Matthias Gräser investigated the particle behaviour by modeling the particle behaviour with stochastic differential equations. With this model it is possible to simulate the impact of several particle parameters and field sequences on the particle response .

In 2010 Matthias Gräser finished his diploma at the Karlsruhe Institue of Technology (KIT). His diploma thesis investigated the nerve stimulation of magnetic fields in the range from 4 kHz to 25 kHz.

Journal Publications

[76902]
Title: Magnetic particle imaging: kinetics of the intravascular signal in vivo.
Written by: J. Haegele, R. Duschka, M. Graeser, C. Schaecke, N, . Panagiotopoulos, K. Lüdtke-\-Buzug, T. M. Buzug, J. Barkhausen, and F. M. Vogt
in: <em>International Journal of Nanomedicine</em>. (2014).
Volume: <strong>9</strong>. Number:
on pages: 4203--4209
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DOI: 10.2147/IJN.S49976
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PMID: 25214784

[BibTex] [pmid]

Note: article

Abstract: {BACKGROUND}: Magnetic particle imaging ({MPI}) uses magnetic fields to visualize superparamagnetic iron oxide nanoparticles ({SPIO}). Today, Resovist(®) is still the reference {SPIO} for {MPI}. The objective of this study was to evaluate the in vivo blood half-life of two different types of Resovist (one from Bayer Pharma {AG}, and one from I'rom Pharmaceutical Co Ltd) in {MPI}. {METHODS}: A Resovist concentration of 50 ?mol/kg was injected into the ear artery of ten New Zealand White rabbits. Five animals received Resovist distributed by I'rom Pharmaceutical Co Ltd and five received Resovist by Bayer Pharma {AG}. Blood samples were drawn before and directly after injection of Resovist, at 5, 10, and 15 minutes, and then every 15 minutes until 120 minutes after the injection. The {MPI} signal of the blood samples was evaluated using magnetic particle spectroscopy. {RESULTS}: The average decline of the blood {MPI} signal from the two distributions differed significantly (P=0.0056). Resovist distributed by Bayer Pharma {AG} showed a slower decline of the {MPI} signal (39.7\% after 5 minutes, 20.5\% after 10 minutes, and 12.1\% after 15 minutes) compared with Resovist produced by I'rom Pharmaceutical Co Ltd (20.4\% after 5 minutes, 7.8\% after 10 minutes, no signal above noise level after 15 minutes). {CONCLUSION}: In {MPI}, the blood half-life of an {SPIO} tracer cannot be equalized to the blood half-life of its {MPI} signal. Resovist shows a very rapid decline of blood {MPI} signal and is thus not suitable as a long circulating tracer. For cardiovascular applications in {MPI}, it may be used as a bolus tracer.

Conference Proceedings

[76902]
Title: Magnetic particle imaging: kinetics of the intravascular signal in vivo.
Written by: J. Haegele, R. Duschka, M. Graeser, C. Schaecke, N, . Panagiotopoulos, K. Lüdtke-\-Buzug, T. M. Buzug, J. Barkhausen, and F. M. Vogt
in: <em>International Journal of Nanomedicine</em>. (2014).
Volume: <strong>9</strong>. Number:
on pages: 4203--4209
Chapter:
Editor:
Publisher:
Series:
Address:
Edition:
ISBN:
how published:
Organization:
School:
Institution:
Type:
DOI: 10.2147/IJN.S49976
URL:
ARXIVID:
PMID: 25214784

[BibTex] [pmid]

Note: article

Abstract: {BACKGROUND}: Magnetic particle imaging ({MPI}) uses magnetic fields to visualize superparamagnetic iron oxide nanoparticles ({SPIO}). Today, Resovist(®) is still the reference {SPIO} for {MPI}. The objective of this study was to evaluate the in vivo blood half-life of two different types of Resovist (one from Bayer Pharma {AG}, and one from I'rom Pharmaceutical Co Ltd) in {MPI}. {METHODS}: A Resovist concentration of 50 ?mol/kg was injected into the ear artery of ten New Zealand White rabbits. Five animals received Resovist distributed by I'rom Pharmaceutical Co Ltd and five received Resovist by Bayer Pharma {AG}. Blood samples were drawn before and directly after injection of Resovist, at 5, 10, and 15 minutes, and then every 15 minutes until 120 minutes after the injection. The {MPI} signal of the blood samples was evaluated using magnetic particle spectroscopy. {RESULTS}: The average decline of the blood {MPI} signal from the two distributions differed significantly (P=0.0056). Resovist distributed by Bayer Pharma {AG} showed a slower decline of the {MPI} signal (39.7\% after 5 minutes, 20.5\% after 10 minutes, and 12.1\% after 15 minutes) compared with Resovist produced by I'rom Pharmaceutical Co Ltd (20.4\% after 5 minutes, 7.8\% after 10 minutes, no signal above noise level after 15 minutes). {CONCLUSION}: In {MPI}, the blood half-life of an {SPIO} tracer cannot be equalized to the blood half-life of its {MPI} signal. Resovist shows a very rapid decline of blood {MPI} signal and is thus not suitable as a long circulating tracer. For cardiovascular applications in {MPI}, it may be used as a bolus tracer.