Double-Tuned Surface 1 H–23 Na Radio Frequency Coils at 7 T: Comparison of Three Decoupling Methods
Journal article
Maggiorelli, F., Boskamp, E.B., Tiberi, G., Retico, A., Symms, M.R., Tosetti, M. and Robb, F. (2019). Double-Tuned Surface 1 H–23 Na Radio Frequency Coils at 7 T: Comparison of Three Decoupling Methods. Applied Magnetic Resonance. 50, pp. 649-661. https://doi.org/10.1007/s00723-019-01116-w
Authors | Maggiorelli, F., Boskamp, E.B., Tiberi, G., Retico, A., Symms, M.R., Tosetti, M. and Robb, F. |
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Abstract | Magnetic Resonance Imaging (MRI) and Spectroscopy (MRS) with nuclei other than protons (X-nuclei) often require the acquisition of proton signal for shimming and co-registration procedures. Double-Tuned Radio Frequency (DT-RF) coils improve these procedures, avoiding the need for movement and repositioning of the subject during the examination. The drawback of DT-RF coils is basically the coupling between the two resonant structures, which increases signal losses leading to a degradation of the final MR image. To improve MR signal quality acquired via DT-RF coils, a suitable decoupling strategy should be implemented. For this purpose, three DT-RF coil prototypes, which differed only in the decoupling method, were built and their performances were compared through workbench measurements. Each prototype consisted of two concentric loops. The inner and outer loops were tuned at sodium (≈ 79 MHz) and proton (≈ 300 MHz) Larmor frequency at 7 Tesla, respectively. Active and passive decoupling designs were compared measuring the Q factor and the S21 parameter for each prototype. Active decoupling was tested as an alternative to the standard passive decoupling with a trap circuit, in which a non-negligible amount of current flows at resonance, perturbing the magnetic field responsible for producing the MR image. Workbench measurements showed satisfactory Q factors and S21 for both active and passive decoupling cases. Thus, active decoupling could be a promising alternative to achieve better MR signal quality. Furthermore, for active decoupling, two circuit elements were examined: PIN diodes and micro-electromechanical system (MEMS) switches. |
Year | 2019 |
Journal | Applied Magnetic Resonance |
Journal citation | 50, pp. 649-661 |
Publisher | Springer |
ISSN | 1613-7507 |
Digital Object Identifier (DOI) | https://doi.org/10.1007/s00723-019-01116-w |
Web address (URL) | http://www.scopus.com/inward/record.url?eid=2-s2.0-85062642600&partnerID=MN8TOARS |
Publication dates | |
Online | 27 Feb 2019 |
Publication process dates | |
Accepted | 03 Dec 2018 |
Deposited | 20 Sep 2022 |
Accepted author manuscript | License File Access Level Open |
Additional information | This version of the article has been accepted for publication, after peer review (when applicable) and is subject to Springer Nature’s AM terms of use, but is not the Version of Record and does not reflect post-acceptance improvements, or any corrections. The Version of Record is available online at: http://dx.doi.org/10.1007/s00723-019-01116 |
https://openresearch.lsbu.ac.uk/item/917w9
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Accepted author manuscript
s00723-019-01116-w.docx | ||
License: Springer Bespoke License | ||
File access level: Open |
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