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Shielded‐coaxial‐cable coils as receive and transceive array elements for 7T human MRI
PURPOSE: To investigate the use of shielded‐coaxial‐cable (SCC) coils as elements for multi‐channel receive‐only and transceive arrays for 7T human MRI and to compare their performance with equivalently sized conventional loop coils. METHODS: The SCC coil element consists of a coaxial loop with inte...
Autores principales: | , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
John Wiley and Sons Inc.
2019
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6899981/ https://www.ncbi.nlm.nih.gov/pubmed/31483530 http://dx.doi.org/10.1002/mrm.27964 |
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author | Ruytenberg, Thomas Webb, Andrew Zivkovic, Irena |
author_facet | Ruytenberg, Thomas Webb, Andrew Zivkovic, Irena |
author_sort | Ruytenberg, Thomas |
collection | PubMed |
description | PURPOSE: To investigate the use of shielded‐coaxial‐cable (SCC) coils as elements for multi‐channel receive‐only and transceive arrays for 7T human MRI and to compare their performance with equivalently sized conventional loop coils. METHODS: The SCC coil element consists of a coaxial loop with interrupted central conductor at the feed‐point side and an interrupted shield at the opposite point. Inter‐element decoupling, transmit efficiency, and sample heating were compared with results from conventional capacitively segmented loop coils. Three multichannel arrays (a 4‐channel receive‐only array and 8‐ and 5‐channel transceive arrays) were constructed. Their inter‐element decoupling was characterized via measured noise correlation matrices and additionally under different flexing conditions of the coils. Thermal measurements were performed and in vivo images were acquired. RESULTS: The measured and simulated [Formula: see text] maps of both SCC and conventional loops were very similar. For all the arrays constructed, the inter‐element decoupling was much greater for the SCC elements than the conventional ones. Even under high degrees of flexion, the coupling coefficients were lower than −10 dB, with a much smaller frequency shift than for the conventional coils. CONCLUSION: Arrays constructed from SCC elements are mechanically flexible and much less sensitive to changes of the coil shape from circular to elongated than arrays constructed from conventional loop coils, which makes them suitable for construction of size adjustable arrays. |
format | Online Article Text |
id | pubmed-6899981 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2019 |
publisher | John Wiley and Sons Inc. |
record_format | MEDLINE/PubMed |
spelling | pubmed-68999812019-12-20 Shielded‐coaxial‐cable coils as receive and transceive array elements for 7T human MRI Ruytenberg, Thomas Webb, Andrew Zivkovic, Irena Magn Reson Med Full Papers—Hardware and Instrumentation PURPOSE: To investigate the use of shielded‐coaxial‐cable (SCC) coils as elements for multi‐channel receive‐only and transceive arrays for 7T human MRI and to compare their performance with equivalently sized conventional loop coils. METHODS: The SCC coil element consists of a coaxial loop with interrupted central conductor at the feed‐point side and an interrupted shield at the opposite point. Inter‐element decoupling, transmit efficiency, and sample heating were compared with results from conventional capacitively segmented loop coils. Three multichannel arrays (a 4‐channel receive‐only array and 8‐ and 5‐channel transceive arrays) were constructed. Their inter‐element decoupling was characterized via measured noise correlation matrices and additionally under different flexing conditions of the coils. Thermal measurements were performed and in vivo images were acquired. RESULTS: The measured and simulated [Formula: see text] maps of both SCC and conventional loops were very similar. For all the arrays constructed, the inter‐element decoupling was much greater for the SCC elements than the conventional ones. Even under high degrees of flexion, the coupling coefficients were lower than −10 dB, with a much smaller frequency shift than for the conventional coils. CONCLUSION: Arrays constructed from SCC elements are mechanically flexible and much less sensitive to changes of the coil shape from circular to elongated than arrays constructed from conventional loop coils, which makes them suitable for construction of size adjustable arrays. John Wiley and Sons Inc. 2019-09-04 2020-03 /pmc/articles/PMC6899981/ /pubmed/31483530 http://dx.doi.org/10.1002/mrm.27964 Text en © 2019 The Authors. Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine This is an open access article under the terms of the http://creativecommons.org/licenses/by/4.0/ License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. |
spellingShingle | Full Papers—Hardware and Instrumentation Ruytenberg, Thomas Webb, Andrew Zivkovic, Irena Shielded‐coaxial‐cable coils as receive and transceive array elements for 7T human MRI |
title | Shielded‐coaxial‐cable coils as receive and transceive array elements for 7T human MRI |
title_full | Shielded‐coaxial‐cable coils as receive and transceive array elements for 7T human MRI |
title_fullStr | Shielded‐coaxial‐cable coils as receive and transceive array elements for 7T human MRI |
title_full_unstemmed | Shielded‐coaxial‐cable coils as receive and transceive array elements for 7T human MRI |
title_short | Shielded‐coaxial‐cable coils as receive and transceive array elements for 7T human MRI |
title_sort | shielded‐coaxial‐cable coils as receive and transceive array elements for 7t human mri |
topic | Full Papers—Hardware and Instrumentation |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6899981/ https://www.ncbi.nlm.nih.gov/pubmed/31483530 http://dx.doi.org/10.1002/mrm.27964 |
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