Current Recycled and Self-Phase Shift to Expand the Length of Radio-Frequency Coils, With Application to Brain and Spine Coil Array at 7T MRI
The use of the 7-Tesla (T) magnetic resonance imaging (MRI) promises improved imaging quality and higher resolution compared with lower-field MRI systems. The design of the loop coil considers the tradeoff between coil size and performance. A larger coil enables deeper field penetration, but it may...
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| Format: | Article |
| Language: | English |
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IEEE
2023-01-01
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| Series: | IEEE Access |
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| Online Access: | https://ieeexplore.ieee.org/document/10292640/ |
| _version_ | 1797635399380631552 |
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| author | Daniel Hernandez Donghyuk Kim Taewoo Nam Yonghwa Jeong Minyeong Seo Eunwoo Lee Junghwan Kim Kyoung-Nam Kim |
| author_facet | Daniel Hernandez Donghyuk Kim Taewoo Nam Yonghwa Jeong Minyeong Seo Eunwoo Lee Junghwan Kim Kyoung-Nam Kim |
| author_sort | Daniel Hernandez |
| collection | DOAJ |
| description | The use of the 7-Tesla (T) magnetic resonance imaging (MRI) promises improved imaging quality and higher resolution compared with lower-field MRI systems. The design of the loop coil considers the tradeoff between coil size and performance. A larger coil enables deeper field penetration, but it may result in poorer field uniformity and localization. On the other hand, a smaller coil offers improved localization capabilities, however, field penetration reduces, and multiple coil elements are required to cover the same space as large coils. Additionally, safety concerns regarding the high-energy absorption of electromagnetic waves in healthy tissues principally limit the use of the 7T MRI, which is measured with the specific absorption rate (SAR). A coil that can generate a uniform magnetic field while maintaining a low SAR is necessary to comply with the SAR limits. We propose a coil design that recirculates the current and provides a phase shift in the same structure to provide a magnetic field over a broad area, thus reducing the number of channels required to cover the same area. We present electromagnetic (EM) simulations of the proposed coil with a magnetic field and SAR computed for the brain and human spine model. We built the coil and acquired images with a phantom using a 7T MRI system. The proposed coil improves the SAR by 43% compared with the reference coil in the spinal area in the case of EM simulations, indicating the imaging quality improvement potential of our proposed coil. |
| first_indexed | 2024-03-11T12:20:34Z |
| format | Article |
| id | doaj.art-31583601b2154a8389491f383181e2cd |
| institution | Directory Open Access Journal |
| issn | 2169-3536 |
| language | English |
| last_indexed | 2024-03-11T12:20:34Z |
| publishDate | 2023-01-01 |
| publisher | IEEE |
| record_format | Article |
| series | IEEE Access |
| spelling | doaj.art-31583601b2154a8389491f383181e2cd2023-11-07T00:02:56ZengIEEEIEEE Access2169-35362023-01-011112043812044810.1109/ACCESS.2023.332682210292640Current Recycled and Self-Phase Shift to Expand the Length of Radio-Frequency Coils, With Application to Brain and Spine Coil Array at 7T MRIDaniel Hernandez0https://orcid.org/0000-0003-0993-1373Donghyuk Kim1https://orcid.org/0000-0003-1381-3943Taewoo Nam2https://orcid.org/0000-0002-4234-7817Yonghwa Jeong3Minyeong Seo4Eunwoo Lee5Junghwan Kim6Kyoung-Nam Kim7Neuroscience Research Institute, Gachon University, Incheon, South KoreaNeuroscience Research Institute, Gachon University, Incheon, South KoreaDepartment of Health Sciences and Technology, GAIHST, Gachon University, Incheon, South KoreaNeuroscience Research Institute, Gachon University, Incheon, South KoreaNeuroscience Research Institute, Gachon University, Incheon, South KoreaDepartment of Biomedical Engineering, Gachon University, Seongnam, South KoreaDepartment of Radiology and EECS, University of Missouri-Columbia, Columbia, MO, USADepartment of Biomedical Engineering, Gachon University, Seongnam, South KoreaThe use of the 7-Tesla (T) magnetic resonance imaging (MRI) promises improved imaging quality and higher resolution compared with lower-field MRI systems. The design of the loop coil considers the tradeoff between coil size and performance. A larger coil enables deeper field penetration, but it may result in poorer field uniformity and localization. On the other hand, a smaller coil offers improved localization capabilities, however, field penetration reduces, and multiple coil elements are required to cover the same space as large coils. Additionally, safety concerns regarding the high-energy absorption of electromagnetic waves in healthy tissues principally limit the use of the 7T MRI, which is measured with the specific absorption rate (SAR). A coil that can generate a uniform magnetic field while maintaining a low SAR is necessary to comply with the SAR limits. We propose a coil design that recirculates the current and provides a phase shift in the same structure to provide a magnetic field over a broad area, thus reducing the number of channels required to cover the same area. We present electromagnetic (EM) simulations of the proposed coil with a magnetic field and SAR computed for the brain and human spine model. We built the coil and acquired images with a phantom using a 7T MRI system. The proposed coil improves the SAR by 43% compared with the reference coil in the spinal area in the case of EM simulations, indicating the imaging quality improvement potential of our proposed coil.https://ieeexplore.ieee.org/document/10292640/MRIantennasspine imagingEM simulations |
| spellingShingle | Daniel Hernandez Donghyuk Kim Taewoo Nam Yonghwa Jeong Minyeong Seo Eunwoo Lee Junghwan Kim Kyoung-Nam Kim Current Recycled and Self-Phase Shift to Expand the Length of Radio-Frequency Coils, With Application to Brain and Spine Coil Array at 7T MRI IEEE Access MRI antennas spine imaging EM simulations |
| title | Current Recycled and Self-Phase Shift to Expand the Length of Radio-Frequency Coils, With Application to Brain and Spine Coil Array at 7T MRI |
| title_full | Current Recycled and Self-Phase Shift to Expand the Length of Radio-Frequency Coils, With Application to Brain and Spine Coil Array at 7T MRI |
| title_fullStr | Current Recycled and Self-Phase Shift to Expand the Length of Radio-Frequency Coils, With Application to Brain and Spine Coil Array at 7T MRI |
| title_full_unstemmed | Current Recycled and Self-Phase Shift to Expand the Length of Radio-Frequency Coils, With Application to Brain and Spine Coil Array at 7T MRI |
| title_short | Current Recycled and Self-Phase Shift to Expand the Length of Radio-Frequency Coils, With Application to Brain and Spine Coil Array at 7T MRI |
| title_sort | current recycled and self phase shift to expand the length of radio frequency coils with application to brain and spine coil array at 7t mri |
| topic | MRI antennas spine imaging EM simulations |
| url | https://ieeexplore.ieee.org/document/10292640/ |
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