A novel receive-only liquid nitrogen (LN2)-cooled RF coil for high-resolution in vivo imaging on a 3-Tesla whole-body scanner

The design and operation of a receive-only liquid nitrogen (LN2)-cooled coil and cryostat suitable for medical imaging on a 3-T whole-body magnetic resonance scanner is presented. The coil size, optimized for murine imaging, was determined by using electromagnetic (EM) simulations. This process is...

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Main Authors: Hu, Bobo, Varma, Gopal, Randell, Chris, Keevil, Stephen F., Schaeffter, Tobias, Glover, Paul
Format: Article
Published: IEEE 2012
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Online Access:https://eprints.nottingham.ac.uk/1630/
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author Hu, Bobo
Varma, Gopal
Randell, Chris
Keevil, Stephen F.
Schaeffter, Tobias
Glover, Paul
author_facet Hu, Bobo
Varma, Gopal
Randell, Chris
Keevil, Stephen F.
Schaeffter, Tobias
Glover, Paul
author_sort Hu, Bobo
building Nottingham Research Data Repository
collection Online Access
description The design and operation of a receive-only liquid nitrogen (LN2)-cooled coil and cryostat suitable for medical imaging on a 3-T whole-body magnetic resonance scanner is presented. The coil size, optimized for murine imaging, was determined by using electromagnetic (EM) simulations. This process is therefore easier and more cost effective than building a range of coils. A nonmagnetic cryostat suitable for small-animal imaging was developed having good vacuum and cryogenic temperature performance. The LN2-cooled probe had an active detuning circuit allowing the use with the scanner's built-in body coil. External tuning and matching was adopted to allow for changes to the coil due to temperature and loading. The performance of the probe was evaluated by comparison of signal-to-noise ratio (SNR) with the same radio-frequency RF) coil operating at room temperature (RT). The performance of the RF coil at RT was also benchmarked against a commercial surface coil with a similar dimension to ensure a fair SNR comparison. The cryogenic coil achieved a 1.6- to twofold SNR gain for several different medical imaging applications: For mouse-brain imaging, a 100-mu m resolution was achieved in an imaging time of 3.5 min with an SNR of 25-40, revealing fine anatomical details unseen at lower resolutions for the same time. For heavier loading conditions, such as imaging of the hind legs and liver, the SNR enhancement was slightly reduced to 1.6-fold. The observed SNR was in good agreement with the expected SNR gain correlated with the loaded-quality factor of RF coils from the EM simulations. With the aid of this end-user-friendly and economically attractive cryogenic RF coil, the enhanced SNR available can be used to improve resolution or reduce the duration of individual scans in a number of biomedical applications.
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spelling nottingham-16302020-05-04T20:21:55Z https://eprints.nottingham.ac.uk/1630/ A novel receive-only liquid nitrogen (LN2)-cooled RF coil for high-resolution in vivo imaging on a 3-Tesla whole-body scanner Hu, Bobo Varma, Gopal Randell, Chris Keevil, Stephen F. Schaeffter, Tobias Glover, Paul The design and operation of a receive-only liquid nitrogen (LN2)-cooled coil and cryostat suitable for medical imaging on a 3-T whole-body magnetic resonance scanner is presented. The coil size, optimized for murine imaging, was determined by using electromagnetic (EM) simulations. This process is therefore easier and more cost effective than building a range of coils. A nonmagnetic cryostat suitable for small-animal imaging was developed having good vacuum and cryogenic temperature performance. The LN2-cooled probe had an active detuning circuit allowing the use with the scanner's built-in body coil. External tuning and matching was adopted to allow for changes to the coil due to temperature and loading. The performance of the probe was evaluated by comparison of signal-to-noise ratio (SNR) with the same radio-frequency RF) coil operating at room temperature (RT). The performance of the RF coil at RT was also benchmarked against a commercial surface coil with a similar dimension to ensure a fair SNR comparison. The cryogenic coil achieved a 1.6- to twofold SNR gain for several different medical imaging applications: For mouse-brain imaging, a 100-mu m resolution was achieved in an imaging time of 3.5 min with an SNR of 25-40, revealing fine anatomical details unseen at lower resolutions for the same time. For heavier loading conditions, such as imaging of the hind legs and liver, the SNR enhancement was slightly reduced to 1.6-fold. The observed SNR was in good agreement with the expected SNR gain correlated with the loaded-quality factor of RF coils from the EM simulations. With the aid of this end-user-friendly and economically attractive cryogenic RF coil, the enhanced SNR available can be used to improve resolution or reduce the duration of individual scans in a number of biomedical applications. IEEE 2012-01 Article NonPeerReviewed Hu, Bobo, Varma, Gopal, Randell, Chris, Keevil, Stephen F., Schaeffter, Tobias and Glover, Paul (2012) A novel receive-only liquid nitrogen (LN2)-cooled RF coil for high-resolution in vivo imaging on a 3-Tesla whole-body scanner. IEEE Transactions on Instrumentation and Measurement, 61 (1). pp. 129-139. ISSN 0018-9456 Biomedical imaging; electromagnetic (EM) modeling; finite-difference time-domain (FDTD) methods; image resolution; magnetic resonance imaging (MRI); medical diagnosis; quality (Q) factor; signal-to-noise ratio (SNR) http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5910383 doi:10.1109/TIM.2011.2157575 doi:10.1109/TIM.2011.2157575
spellingShingle Biomedical imaging; electromagnetic (EM) modeling; finite-difference time-domain (FDTD) methods; image resolution; magnetic resonance imaging (MRI); medical diagnosis; quality (Q) factor; signal-to-noise ratio (SNR)
Hu, Bobo
Varma, Gopal
Randell, Chris
Keevil, Stephen F.
Schaeffter, Tobias
Glover, Paul
A novel receive-only liquid nitrogen (LN2)-cooled RF coil for high-resolution in vivo imaging on a 3-Tesla whole-body scanner
title A novel receive-only liquid nitrogen (LN2)-cooled RF coil for high-resolution in vivo imaging on a 3-Tesla whole-body scanner
title_full A novel receive-only liquid nitrogen (LN2)-cooled RF coil for high-resolution in vivo imaging on a 3-Tesla whole-body scanner
title_fullStr A novel receive-only liquid nitrogen (LN2)-cooled RF coil for high-resolution in vivo imaging on a 3-Tesla whole-body scanner
title_full_unstemmed A novel receive-only liquid nitrogen (LN2)-cooled RF coil for high-resolution in vivo imaging on a 3-Tesla whole-body scanner
title_short A novel receive-only liquid nitrogen (LN2)-cooled RF coil for high-resolution in vivo imaging on a 3-Tesla whole-body scanner
title_sort novel receive-only liquid nitrogen (ln2)-cooled rf coil for high-resolution in vivo imaging on a 3-tesla whole-body scanner
topic Biomedical imaging; electromagnetic (EM) modeling; finite-difference time-domain (FDTD) methods; image resolution; magnetic resonance imaging (MRI); medical diagnosis; quality (Q) factor; signal-to-noise ratio (SNR)
url https://eprints.nottingham.ac.uk/1630/
https://eprints.nottingham.ac.uk/1630/
https://eprints.nottingham.ac.uk/1630/