Design and evaluation of Overhauser enhanced MRI visible markers

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Doctoral thesis (article-based)
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Date

2000-10-27

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Degree programme

Language

en

Pages

47, [31]

Series

Helsinki University of Technology, Applied Electronics Laboratory. Series B, Research reports, 7

Abstract

This thesis deals with the theoretical principles, design and construction of a small-sized marker which is visible in magnetic resonance images. The nuclear magnetic resonance signal emitted by the marker is enhanced by the use of the Overhauser phenomenon. Different marker configurations were designed and constructed. A point-like marker was coupled to the feeding cable by loop and loop-gap geometries, and circuit analogies were presented to the loop-gap geometry and to the Overhauser phenomenon. An elongated, cylindrical marker was realized by constructing a transmission-line marker where a microwave shield and tapered coupling were included in the design. The markers' feasibility in interventional use was demonstrated in phantom and in vitro experiments, and the loop-gap marker was used in high-resolution MR studies.

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Keywords

interventional MRI, device visualization, Overhauser effect

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Parts

  • R. P. Joensuu, R. E. Sepponen, A. E. Lamminen, C.-G. M. Standertskjöld-Nordenstam, Interventional MR imaging: Demonstration of the feasibility of the Overhauser marker enhancement (OMEN) technique. Acta Radiologica 38: 43-46, 1997.
  • R. P. Joensuu, R. E. Sepponen, A. E. Lamminen, S. E. Savolainen, C.-G. M. Standertskjöld-Nordenstam, High-Accuracy MR tracking of interventional devices: The Overhauser Marker Enhancement (OMEN) technique. Magnetic Resonance in Medicine 40: 914-921, 1998.
  • R. P. Joensuu, R. E. Sepponen, A. E. Lamminen, C.-G. M. Standertskjöld-Nordenstam, A shielded Overhauser marker for MR tracking of interventional devices. Magnetic Resonance in Medicine 43: 139-145, 2000.
  • R. P. Joensuu, R. E. Sepponen, T. E. Autti, J. I. Tanttu, A. E. Lamminen, C.-G. M. Standertskjöld-Nordenstam, A sub-voxel sized Overhauser phantom for high-resolution studies in MRI. Report B6, Applied Electronics Laboratory, Helsinki University of Technology, 2000.

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Permanent link to this item

https://urn.fi/urn:nbn:fi:tkk-002410