Effects of tissues and geometric shapes of phantoms on the specific energy absorption rate

Saleh, Gameel; Sibaii, Fatima; Alashban, Najla; Alkhateeb, Haneen; Hegazi, Fatma Mohammed; Hegazi, Mariam

doi:10.1002/mmce.21252

Cited by 9 publications

(5 citation statements)

References 7 publications

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“…SAR is a constraint design parameter; it specifies the amount of energy absorbed by a human body tissue. SAR should not exceed certain values that are a measure to the increase in biological tissue temperature by one degree Celsius [35]. This is important for assessing patient safety when using medical implants with embedded antennas.…”

Section: Antenna In the Skin Layer Model: Results And Analysismentioning

confidence: 99%

A Miniaturized Enhanced Gain Wideband Metamaterial Loaded Planar Inverted F-L Implant Antenna

Salama,

ZYOUD,

Abuelhaija

et al. 2024

Preprint

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The antenna presented in this work is a planar inverted F-L (PIFLIA) implant antenna. The PIFLIA characteristics are improved by loading it with a metamaterial. A metamaterial is an artificial material engineered having properties that are unavailable in nature. The metamaterial is designed using an H-shaped split rectangular resonator as the unit cell. Unit cells are the main element of metamaterials. The antenna is constructed on a substrate material of RO3010. To reduce the antenna's size and enhance its bandwidth, a 2x2 array of the metamaterial unit cell is printed on the opposite side of the substrate. While, the planar inverted F-L antenna is on the upper side of the substrate. This arrangement results in a compact antenna structure. The size of the metamaterial-loaded PIFLA antenna is specified as 16 × 10 × 1.28 mm³. The structure and simulation of the proposed antenna are performed using CST (Computer Simulation Technology) software, a popular tool for electromagnetic simulations. The relative permittivity, ε_r, relative permeability, μ_r, and refractive index, n of the metamaterial unit cell are determined from the scattering parameters and plotted using Matlab, a high-level programming language commonly used for numerical simulations and data analysis. The simulated S_11 of the antenna indicates excellent performance with less than -32 dB return loss in the industrial, scientific, and medical (ISM) band and the medical implant communication services (MICS) band. Additionally, the antenna supports a wide frequency bandwidth, including the MICS band [393.3 – 412.64 MHz], the ISM band [2 – 2.6 GHz], and two additional frequency bands: [1.2 – 1.3 GHz] and [2.8 - 3.6 GHz]. The introduced metamaterial-loaded PIFLA implant antenna is implemented, and the measurements were in consistent with the simulation results.

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Section: Antenna In the Skin Layer Model: Results And Analysismentioning

confidence: 99%

A Miniaturized Enhanced Gain Wideband Metamaterial Loaded Planar Inverted F-L Implant Antenna

Salama,

ZYOUD,

Abuelhaija

et al. 2024

Preprint

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“…The structure also consists of a meander-printed dipole RF coil (on the right) comprising two parallel quarter-wave transmission lines, which act as a matching network to match the 10 Ω RF coil input impedance [23,26] with the 50 Ω transmission line impedance. Notably, the effect of biological tissues on SAR values when using the same coil geometry is explained in [27]. Furthermore, multiple halfwavelength (N × λ/2) transmission line cables are used to connect the PA to the RF coil, since the length of the cables maintains the applicability of the current forcing property.…”

Section: Design Of the Built-in Coil Current Sensing Methodsmentioning

confidence: 99%

Built-In Coil Current Sensing for 7-Tesla 1H/23Na and 1H/31P Magnetic Resonance Imaging

Abuelhaija,

Saleh,

Issa

et al. 2024

J. Electromagn. Eng. Sci

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This article introduces two designs for dual-tuned built-in radio-frequency coil current sensing in 7-Tesla magnetic resonance imaging based on the current forcing property of the quarter-wave transmission line. The first design offers dual-tuned built-in coil current sensing at 1H/23Na resonant frequencies to probe the coil current consecutively at 298 MHz and 78.8 MHz, without the need for any integrated sensor on the coil. The second design enables dual-tuned built-in coil current sensing at 1H/31P resonant frequencies to probe the coil current at 298 MHz and 120 MHz consecutively. The first design achieved good matching (<-40 dB) and low insertion loss (<0.5 dB) for 1H and 23Na magnetic resonance signals. The 1H/31P design also exhibited good matching (<-30 dB) and low insertion loss (<0.67 dB). Therefore, both designs show promising potential for monitoring current flows in dual-tuned coils at the Larmor frequencies of different atomic nuclei.

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“…For 7‐Tesla MRI, the 1H, 13C, 23Na, 31P, and 19F coils resonate at 298, 75, 78.8, 120.6 , and 280 MHz, respectively. Single and multichannel RF coils 1,2 are used with the aim to maximize the rotating magnetic field, enhance the signal‐to‐noise ratio (SNR), minimize the electric field and hence the energy specific absorption rate 3–5 …”

Section: Introductionmentioning

confidence: 99%

Multi‐ and dual‐tuned microstripline‐based transmit/receive switch for 7‐Tesla magnetic resonance imaging

Abuelhaija

Saleh

Nashwan

et al. 2021

Int J Imaging Syst Tech

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This article introduces two new designs of transmit/receive switches for 7‐Tesla magnetic resonance imaging. Both designs based on a microstripline coupler technology. In the first design, a different single frequency signals can be handled to/from a radio frequency coil using smart tuning network. In the second design, a dual‐tuned 1H/23Na transmit/receive switch is designed to handle a dual resonant signal to a dual resonant 1H/23Na coil, simultaneously and without tuning. In transmit and receive, the first design achieved good matching (‐20 dB), and low insertion loss (0.78 dB) for the 1H, 19F, 31P, 13C, and 23Na magnetic resonance signals with high isolation (61 dB). Similarly, the dual‐tuned 1H/23Na switch achieved good matching (<−11.5 dB) and low insertion loss (1.0 dB) with high isolation (67 dB), whereas for 1H/31P switch, good matching has been achieved (<−12 dB) and low insertion loss (0.96 dB) with high isolation (62 dB). The first proposed switch enables the use of the same switch with different coils resonating at Larmor frequencies of different atomic nuclei. The second switch can handle a dual resonant signal to a single dual resonant coil. The first design is promising in reducing the costs by using the same switch with different coils. The second design is promising in the integration with multichannel dual resonant coil.

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Effects of tissues and geometric shapes of phantoms on the specific energy absorption rate

Cited by 9 publications

References 7 publications

A Miniaturized Enhanced Gain Wideband Metamaterial Loaded Planar Inverted F-L Implant Antenna

A Miniaturized Enhanced Gain Wideband Metamaterial Loaded Planar Inverted F-L Implant Antenna

Built-In Coil Current Sensing for 7-Tesla 1H/23Na and 1H/31P Magnetic Resonance Imaging

Multi‐ and dual‐tuned microstripline‐based transmit/receive switch for 7‐Tesla magnetic resonance imaging

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