Magnetic Resonance Imaging

Nuclear Magnetic Resonance is a powerful tool for assessing and investigating the interior of living systems without ionizing radiation. Being already widely applied in medicine and biomedical research, it is also subject to dynamic research activities. Magnetic resonance methods can be used to measure a plethora of parameters characterizing the structure, status, and function of biological tissues, such as water content, concentration of metabolites, temperature, microscopic structure, pH, diffusion coefficients, status of blood perfusion, etc.

Our main research focus is diffusion-weighted MR imaging, which aims at measuring the diffusion-related motion of water molecules in living tissue as a means of assessing tissue structure. This already plays a key role in clinical diagnostics of stroke where it is used to detect cell swelling. A number of approaches for measuring different characteristics of microscopic tissue structure have been proposed and require investigation.

Currently, the following projects are investigated in our institute:

Publications

[in press] [2017] [2016] [2015] [2014] [2012] [2011]

in press [to top]

  • V. Methot, Ulloa, P. and Koch, M. A.: Varying the mixing time of the double diffusion experiment: A better experimental design for pore size estimation, In: Magnetic Resonance Materials in Physics, Biology and Medicine, in press.
     
  • P. Gurumurthy, Hagen, C., Ulloa, P., Koch, M. A. and Buzug, T. M.: Computational fluid dynamics simulations and phase contrast-MRI validation of airflow in human pharynx during obstructive sleep apnea, In: Biomedizinische Technik / Biomedical Engineering, in press.
     
  • P. Ulloa, Methot, V. and Koch, M. A.: Experimental study of bias in apparent exchange rate measurements, In: Magnetic Resonance Materials in Physics, Biology and Medicine, in press.
     
  • P. Ulloa, Methot, V. and Koch, M. A.: Experimental validation of a bias in apparent exchange rate measurements, Current Directions in Biomedical Engineering, in press.
     
  • A. Globisch, Melchert, U. H., Erdmann, C. and Koch, M.: Implementation of a correction procedure to decrease the effect of PSF-related signal leakage in 23Na NMRS, In: Biomedizinische Technik / Biomedical Engineering, in press.
     
  • V. Methot, Ulloa, P. and Koch, M. A.: Pore size estimation from double diffusion encoding, Current Directions in Biomedical Engineering, in press.
     

2017 [to top]

  • P. Ulloa, Methot, V. and Koch, M. A.: Bias in the apparent exchange rate measurements: insight from numerical simulations, In: 25th Annual Meeting of the International Society for Magnetic Resonance in Medicine, Honolulu, 1085, 2017.
     
  • V. Methot, Ulloa, P. and Koch, M. A.: Pore size estimation using the mixing time dependence of a double diffusion encoding experiment: experimental validation on a clinical MR system, In: 25th Annual Meeting of the International Society for Magnetic Resonance in Medicine, Honolulu, 717, 2017.
     

2016 [to top]

  • V. Methot and Koch, M. A.: Pore size distribution estimation using the mixing time dependency of a double diffusion encoding experiment: a proof of concept from Monte Carlo simulated data, In: Magnetic Resonance Materials in Physics, Biology and Medicine, S165--S167, 2016, DOI: 10.1007/s10334-016-0569-9.
     
  • P. Ulloa, Benedik, A., Landmesser, R. and Koch, M. A.: Water-in-oil Emulsion as a Simple Phantom for Validation of Double Diffusion Encoding MRI Sequences, In: Magnetic Resonance Materials in Physics, Biology and Medicine, S48--S49, 2016, DOI: 10.1007/s10334-016-0568-x.
     
  • P. Gurumurthy, Ulloa, P., Kluck, C., Buzug, T. M. and Koch, M. A.: Investigation of pharyngeal flow patterns using phase contrast-MRI, In: Biomedical Engineering / Biomedizinische Technik, S227, 2016, DOI: 10.1515/bmt-2016-5018.
     
  • P. Gurumurthy, Ulloa, P., Kluck, C., Buzug, T. M. and Koch, M. A.: Study of fluid flow patterns in a human pharynx phantom using phase contrast-MRI, In: Magnetic Resonance Materials in Physics, Biology and Medicine, S201--S202, 2016, DOI: 10.1007/s10334-016-0569-9.
     
  • M. Schmiedel, Möller, A., Koch, M. A. and Mertins, A.: Designing a compact MRI motion phantom, Current Directions in Biomedical Engineering, 2(1), 417--474, 2016, DOI: 10.1515/cdbme-2016-0104.
     
  • G. Bringout, Löfberg, J., Ulloa, P., Koch, M. A. and Buzug, T. M.: Designing coils to minimize the maximal induced electrical field amplitude in a patient, In: International Workshop on Magnetic Particle Imaging, 32, 2016.
     
  • V. Methot and Koch, M. A.: Exploring model limitations for double diffusion encoding MRI, In: Breaking the Barriers of Diffusion MRI: Workshop of the International Society for Magnetic Resonance in Medicine, September 11--16, 2016, Lisbon, 2016.
     
  • M. Schmiedel, Möller, A., Koch, M. A. and Mertins, A.: Design of a Motion Phantom for Magnetic Resonance Imaging, In: Student Conference on Medical Engineering Science, Lübeck, 251--254, 2016.
     
  • M. A. Koch and Ulloa, P.: Determination of the pore size distribution by double diffusion encoding, In: New dimensions in diffusion encoding (Workshop Jan 11-14, 2016, Bäckaskog Castle, Sweden), 12, 2016, DOI: 10.3389/conf.FPHY.2016.01.00012.
     
  • N. Shemesh, Jespersen, S. N., Alexander, D. C., Cohen, Y., Drobnjak, I., Dyrby, T. B., Finsterbusch, J., Koch, M. A., Kuder, T., Laun, F., Lawrenz, M., Lundell, H., Mitra, P. P., Nilsson, M., Özarslan, E., Topgaard, D. and Westin, C. -F.: Conventions and Nomenclature for Double Diffusion Encoding NMR and MRI, Magnetic Resonance in Medicine, 75(1), 82-87, 2016, DOI: 10.1002/mrm.25901.
     

2015 [to top]

  • P. Ulloa, Wottschel, V. and Koch, A. M.: Studying the extracellular contribution to the double wave vector diffusion-weighted signal, Current Directions in Biomedical Engineering, 1(1), 240-244, 2015, DOI: 10.1515/cdbme-2015-0060.
     
  • S. Ariyamitr and Koch, M. A.: Analyzing the Impact of Different Path Termination Conditions in a Probabilistic Fiber Tracking Algorithm, In: Deutsche Gesellschaft für Biomedizinische Technik Jahrestagung, 2015.
     
  • P. Ulloa, Wottschel, V. and Koch, M. A.: Investigating the Extracellular Contribution to the Double-Wave-Vector Diffusion-Weighted Signal, In: 23rd Annual Meeting of the International Society for Magnetic Resonance in Medicine, Toronto, 2786, 2015.
     

2014 [to top]

  • A. Biber, Meyer, M. and Koch, M. A.: Visualizing Microscopic Hemorrhages with Susceptibility-Weighted Imaging (SWI) for Forensic Applications, In: Deutsche Gesellschaft für Biomedizinische Technik Jahrestagung, s539-s542, 2014, DOI: 10.1515/bmt-2014-5008.
     
  • A. Timmermeyer, Koch, M. A. and Frydrychowicz, A.: Development and Validation of a Tool for Pulse Wave Velocity Measurements in MRI Phase Contrast Data, In: Deutsche Gesellschaft für Biomedizinische Technik Jahrestagung, s543-s546, 2014, DOI: 10.1515/bmt-2014-5008.
     
  • P. Ulloa, Wottschel, V. and Koch, M. A.: Extracellular Space Contribution to the Double Wave Vector Diffusion-Weighted Signal, In: Deutsche Gesellschaft für Biomedizinische Technik Jahrestagung, s568, 2014, DOI: 10.1515/bmt-2014-5008.
     
  • M. Meyer, Biber, A. and Koch, M. A.: Chasing the Zebra. The Quest for the Origin of a Stripe Artifact in Diffusion-Weighted MRI, In: Deutsche Gesellschaft für Biomedizinische Technik Jahrestagung, s535-s538, 2014, DOI: 10.1515/bmt-2014-5008.
     

2012 [to top]

  • M. A. Koch and Finsterbusch, J.: Double Wave Vector Diffusion Weighting in Wallerian Degeneration, In: 20th Annual Meeting of the International Society for Magnetic Resonance in Medicine, Montréal, 3564, 2012.
     

2011 [to top]

  • M. A. Koch and Finsterbusch, J.: Towards compartment size estimation in vivo based on double wave vector diffusion weighting, NMR in Biomedicine, 24(10), 1422-1432, 2011, DOI: 10.1002/nbm.1711.