Abstract
Metamaterial-based designs in ultra-high field (≥7 T) MRI have the promise of increasing the local magnetic resonance imaging (MRI) signal and potentially even the global efficiency of both the radiofrequency (RF) transmit and receive resonators. A recently proposed metamaterial-like structure—comprised of a high-permittivity dielectric material and a set of evenly distributed copper strips—indeed resulted in a local increase in RF transmission. Here, we demonstrate that non-uniform designs of this metamaterial-like structure can be used to boost the ultimate RF field distribution. A non-uniform dielectric distribution can yield longer electric dipoles, thus extending the RF transmit field coverage. A non-uniform distribution of conducting strips enables the tailoring of the local electric field hot spots, where a concave distribution resulted in lower power deposition. Simulations of the brain and calf regions using our new metamaterial-like design, which combines non-uniform distributions of both the dielectric and conducting strips, revealed a 1.4-fold increase in the RF field coverage compared to the uniform distribution, and a 1.5–2-fold increase in the transmit efficiency compared to the standard surface-coil.
Original language | English |
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Article number | 2250 |
Journal | Sensors |
Volume | 24 |
Issue number | 7 |
Early online date | 31 Mar 2024 |
DOIs | |
Publication status | Published - Apr 2024 |
Bibliographical note
This paper is an extension version of the conference paper: Abstract P91; Vol. 36, Book of Abstracts ESMRMB 9 2023 Online 39th Annual Scientific Meeting 4–7 October 2023.We are grateful to E. Tegareh from the MRI technician team at the Weizmann Institute for assistance with the MRI scans.
This work was partially supported by the Israel Innovation Authority through its Metamaterials Consortium.
Publisher Copyright:
© 2024 by the authors.
All Science Journal Classification (ASJC) codes
- Analytical Chemistry
- Information Systems
- Atomic and Molecular Physics, and Optics
- Biochemistry
- Instrumentation
- Electrical and Electronic Engineering