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:

Cooperations

  • Philips Healthcare, Hamburg
  • Siemens Healthineers
  • Universitätsklinikum Schleswig-Holstein
  • Universitätsklinikum Hamburg-Eppendorf

Publications

2023[ to top ]
  • Extra-axonal contribution to double diffusion encoding-based pore size estimates in the corticospinal tract. Ulloa, P.; Methot, V.; Wottschel, V.; Koch, M. A. In Magnetic Resonance Materials in Physics, Biology and Medicine, 36(4), pp. 589–612. 2023.
2022[ to top ]
  • Bimodal Interventional Instrument Markers for Magnetic Particle Imaging and Magnetic Resonance Imaging---A Proof-of-Concept Study. Wegner, Franz; Lüdtke-Buzug, Kerstin; Cremers, Sjef; Friedrich, Thomas; Sieren, Malte M.; Haegele, Julian; Koch, Martin A.; Saritas, Emine U.; Borm, Paul; Buzug, Thorsten M.; Barkhausen, Joerg; Ahlborg, Mandy. In Nanomaterials, 12(10), p. 1758. MDPI, 2022.
2020[ to top ]
  • Monitoring Intracranial Cerebral Hemorrhage Using Multi-Contrast Real-Time Magnetic Particle Imaging. Szwargulski, Patryk; Wilmes, Maximilian; Javidi, Ehsan; Thieben, Florian; Graeser, Matthias; Koch, Martin; Grüttner, Cordula; Adam, Gerhard; Gerloff, Christian; Magnus, Tim; Knopp, Tobias; Ludewig, Peter. In ACS Nano, 14(10), pp. 13913–13923. 2020.
2019[ to top ]
  • Head Movement Detection from Radial k-Space Lines using Convolutional Neural Networks -- A Digital Phantom Study. Wattenberg, M.; Hagenah, J.; Schareck, C.; Ernst, F.; Koch, M. A. In 27th Annual Meeting International Society for Magnetic Resonance in Medicine, May 11--16, 2019, Montréal, Québec, Canada, p. 4859. 2019.
  • MRI flow measurements with a flexible stenosis phantom. Ibbeken, Alina; Gurumurthy, Pragathi; Zell, Fenja; Hagen, Christina; Koch, Martin A.; Buzug, Thorsten M. In Current Directions in Biomedical Engineering, 5(1), pp. 565–568. 2019.
  • Impact of different respiratory monitoring techniques on respiration-dependent stroke-volume measurements assessed by real-time magnetic resonance imaging. Becker, Hendrik; Wattenberg, Maximilian; Barth, Peter; Laser, Kai Thorsten; Burchert, Wolfgang; Hermann, Körperich. In Journal of Medical Physics. 2019.
2018[ to top ]
  • Learning motion artefacts in non-Cartesian magnetic resonance imaging. Koch, M. A.; Hagenah, J.; Wattenberg, M.; Ernst, F. In Biomedizinische Technik / Biomedical Engineering, Vol. 63, p. P104. 2018.
  • First heating measurements of endovascular stents in magnetic particle imaging. Wegner, Franz; Friedrich, Thomas; Panagiotopoulos, Nikolaos; Valmaa, Sarah; Goltz, Jan P; Vogt, Florian M; Koch, Martin A; Buzug, Thorsten M; Barkhausen, Joerg; Haegele, Julian. In Physics in Medicine and Biology, 63(4), p. 045005. IOP Publishing, 2018.
  • Development of a graphical user interface and cross manufacturer adaptation of a program for determining the pulse wave velocity in the aorta from phase-contrast magnetic resonance images. Schareck, Constantin; Oechtering, Thekla H.; Frydrychowicz, Alex; Koch, Martin A. In Current Directions in Biomedical Engineering, 4(1), pp. 477–480. 2018.
2017[ to top ]
  • Experimental validation of a bias in apparent exchange rate measurements. Ulloa, P.; Methot, V.; Koch, M. A. In Current Directions in Biomedical Engineering, 3(2), pp. 529–532. 2017.
  • Effects of replacing the nasal cavity with a simple pipe like structure in CFD simulations of the airflow within the upper airways of OSA patients with patient individual flow rates. Hagen, Christina; Gurumurthy, Pragathi; Buzug, Thorsten M. In Current Directions in Biomedical Engineering, 3(2), pp. 795–798. 2017.
  • Computational fluid dynamics simulations and phase contrast-MRI validation of airflow in human pharynx during obstructive sleep apnea. Gurumurthy, P.; Hagen, C.; Ulloa, P.; Koch, M. A.; Buzug, T. M. In Biomedizinische Technik / Biomedical Engineering, Vol. 62, p. S507. 2017.
  • Implementation of a correction procedure to decrease the effect of PSF-related signal leakage in 23Na NMRS. Globisch, A.; Melchert, U. H.; Erdmann, C.; Koch, M. In Biomedizinische Technik / Biomedical Engineering, Vol. 62, p. S341. 2017.
  • Varying the mixing time of the double diffusion experiment: A better experimental design for pore size estimation. Methot, V.; Ulloa, P.; Koch, M. A. In Magnetic Resonance Materials in Physics, Biology and Medicine, 30 (Suppl. 1), pp. S633-S634. 2017.
  • Bias in the apparent exchange rate measurements: insight from numerical simulations. Ulloa, Patricia; Methot, Vincent; Koch, Martin A. In 25th Annual Meeting of the International Society for Magnetic Resonance in Medicine, Honolulu, p. 1085. 2017.
  • Pore size estimation from double diffusion encoding. Methot, V.; Ulloa, P.; Koch, M. A. In Current Directions in Biomedical Engineering, 30(2), pp. 627–630. 2017.
  • Time-resolved, 3-dimensional, 3-directionally velocity sensitive phase-contrast MRI for the investigation of flow patterns in a human pharynx phantom during obstructive sleep apnea. Gurumurthy, P.; Hagen, C.; Ulloa, P.; Methot, V.; Oechtering, T. H.; Frydrychowicz, A.; Koch, M. A.; Buzug, T. M. In Magnetic Resonance Materials in Physics, Biology and Medicine, Vol. 30 (Suppl. 1), p. S23. 2017.
  • Experimental study of bias in apparent exchange rate measurements. Ulloa, P.; Methot, V.; Koch, M. A. In Magnetic Resonance Materials in Physics, Biology and Medicine, Vol. 30, pp. S173-S174. 2017.
  • Pore size estimation using the mixing time dependence of a double diffusion encoding experiment: experimental validation on a clinical MR system. Methot, Vincent; Ulloa, Patricia; Koch, Martin A. In 25th Annual Meeting of the International Society for Magnetic Resonance in Medicine, Honolulu, p. 717. 2017.
2016[ to top ]
  • Pore size distribution estimation using the mixing time dependency of a double diffusion encoding experiment: a proof of concept from Monte Carlo simulated data. Methot, Vincent; Koch, Martin A. In Magnetic Resonance Materials in Physics, Biology and Medicine, Vol. 29, pp. S165-S167. Springer, Berlin, 2016.
  • Design of a Motion Phantom for Magnetic Resonance Imaging. Schmiedel, Max; Möller, Anita; Koch, Martin A.; Mertins, Alfred. In Student Conference on Medical Engineering Science, Lübeck, pp. 251–254. 2016.
  • Conventions and Nomenclature for Double Diffusion Encoding NMR and MRI. Shemesh, Noam; Jespersen, Sune N.; Alexander, Daniel C.; Cohen, Yoram; Drobnjak, Ivana; Dyrby, Tim B.; Finsterbusch, Jurgen; Koch, Martin A.; Kuder, Tristan; Laun, Fredrik; Lawrenz, Marco; Lundell, Henrik; Mitra, Partha P.; Nilsson, Markus; Özarslan, Evren; Topgaard, Daniel; Westin, Carl-Fredrik. In Magnetic Resonance in Medicine, 75(1), pp. 82–87. 2016.
  • Investigation of pharyngeal flow patterns using phase contrast-MRI. Gurumurthy, Pragathi; Ulloa, Patricia; Kluck, Christina; Buzug, Thorsten M.; Koch, Martin A. In Biomedical Engineering / Biomedizinische Technik, Vol. 61, p. S227. de Gruyter, Berlin, 2016.
  • Water-in-oil Emulsion as a Simple Phantom for Validation of Double Diffusion Encoding MRI Sequences. Ulloa, Patricia; Benedik, Anastasia; Landmesser, Rabea; Koch, Martin A. In Magnetic Resonance Materials in Physics, Biology and Medicine, Vol. 29, pp. S48-S49. Springer, Berlin, 2016.
  • Study of fluid flow patterns in a human pharynx phantom using phase contrast-MRI. Gurumurthy, Pragathi; Ulloa, Patricia; Kluck, Christina; Buzug, Thorsten M.; Koch, Martin A. In Magnetic Resonance Materials in Physics, Biology and Medicine, Vol. 29, pp. S201-S202. Springer, Berlin, 2016.
  • Designing a compact MRI motion phantom. Schmiedel, Max; Möller, Anita; Koch, Martin A.; Mertins, A. In Current Directions in Biomedical Engineering, 2(1), pp. 417–474. 2016.
  • Designing coils to minimize the maximal induced electrical field amplitude in a patient. Bringout, Gael; Löfberg, Johan; Ulloa, Patricia; Koch, Martin A.; Buzug, Thorsten M. In International Workshop on Magnetic Particle Imaging, p. 32. 2016.
  • Direct extraction of a k0 navigator from golden angle stack-of-stars profiles – a model-based filtering approach. Technical Report (Master thesis), . Wattenberg, Maximilian. Master thesis. University of Lübeck, Institute of Medical Engineering, Philips GmbH Innovative Technologies, Research Laboratories, in Hamburg, 2016.
  • Determination of the pore size distribution by double diffusion encoding. Koch, Martin A.; Ulloa, Patricia. In New dimensions in diffusion encoding (Workshop Jan 11-14, 2016, Bäckaskog Castle, Sweden), of Frontiers in Physics, S. N. Jespersen, K. Bryskhe, M. Nilsson, D. Topgaard, C.-F. Westin (eds.), p. 12. 2016.
  • Exploring model limitations for double diffusion encoding MRI. Methot, Vincent; Koch, Martin A. In Breaking the Barriers of Diffusion MRI: Workshop of the International Society for Magnetic Resonance in Medicine, September 11--16, 2016, Lisbon. 2016.
2015[ to top ]
  • Investigating the Extracellular Contribution to the Double-Wave-Vector Diffusion-Weighted Signal. Ulloa, P.; Wottschel, V.; Koch, M. A. In 23rd Annual Meeting of the International Society for Magnetic Resonance in Medicine, Toronto, p. 2786. 2015.
  • Studying the extracellular contribution to the double wave vector diffusion-weighted signal. Ulloa, P.; Wottschel, V.; Koch, A.M. In Current Directions in Biomedical Engineering, 1(1), pp. 240–244. 2015.
  • Analyzing the Impact of Different Path Termination Conditions in a Probabilistic Fiber Tracking Algorithm. Ariyamitr, Schonlatis; Koch, Martin A. In Deutsche Gesellschaft für Biomedizinische Technik Jahrestagung. 2015.
2014[ to top ]
  • Development and Validation of a Tool for Pulse Wave Velocity Measurements in MRI Phase Contrast Data. Timmermeyer, Anja; Koch, Martin A.; Frydrychowicz, Alex. In Deutsche Gesellschaft für Biomedizinische Technik Jahrestagung, Vol. 59, pp. s543-s546. 2014.
  • Extracellular Space Contribution to the Double Wave Vector Diffusion-Weighted Signal. Ulloa, Patricia; Wottschel, Viktor; Koch, Martin A. In Deutsche Gesellschaft für Biomedizinische Technik Jahrestagung, Vol. 59, p. s568. 2014.
  • Chasing the Zebra. The Quest for the Origin of a Stripe Artifact in Diffusion-Weighted MRI. Meyer, Marius; Biber, Adil; Koch, Martin A. In Deutsche Gesellschaft für Biomedizinische Technik Jahrestagung, Vol. 59, pp. s535-s538. 2014.
  • Visualizing Microscopic Hemorrhages with Susceptibility-Weighted Imaging (SWI) for Forensic Applications. Biber, Adil; Meyer, Marius; Koch, Martin A. In Deutsche Gesellschaft für Biomedizinische Technik Jahrestagung, Vol. 59, pp. s539-s542. 2014.
2012[ to top ]
  • Double Wave Vector Diffusion Weighting in Wallerian Degeneration. Koch, M. A.; Finsterbusch, J. In 20th Annual Meeting of the International Society for Magnetic Resonance in Medicine, Montréal, p. 3564. 2012.
2011[ to top ]
  • Towards compartment size estimation in vivo based on double wave vector diffusion weighting. Koch, Martin A.; Finsterbusch, Jürgen. In NMR in Biomedicine, 24(10), pp. 1422–1432. John Wiley & Sons, Ltd, 2011.