Simulation Design of Incremental Leg Tapered Birdcage Coil for Head Imaging at 4.7T MRI

Song, Hyunwoo; Kim, Kyoung Nam; Hernández, Daniel

doi:10.3390/app11052064

Cited by 3 publications

(2 citation statements)

References 23 publications

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“…Another method of improving the transmission metrics of the BC coil is altering the geometry, e.g., by using an oval or asymmetric cross section that more closely matches the shape of the human body [40], or a design where the ends taper to a small diameter end-rings at one end [41]. For body coils these strategies are not possible to employ, as the design must come as close to the cylindrical bore geometry as possible to maximize the available space.…”

Section: Alternative Bc Sar Reduction Strategiesmentioning

confidence: 99%

Metamaterial Liner for MRI Excitation—Part 2: Design and Performance at 4.7T

2022

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The theoretical foundations of a metamaterial (MM) liner for the MRI bore that facilitates the propagation of reduced-cutoff cylindrical waveguide modes are presented in the Part 1 companion paper to this work. Here, in Part 2, the practical design and modelling of the novel MM liner is applied to a body MRI radio-frequency (RF) transmitter for 4.7T. An equivalent network mesh model is developed to reduce the distributed structure of the MM to one that uses lumped discrete tuning elements. The close match between full-wave simulation and the network model is demonstrated by comparison of the longitudinal propagation dispersion curves and input impedance. The application of the methods developed for analysis of the MM liner behavior are demonstrated in the design of a practical MM liner as an effective MRI RF transmitter. The liner's simulated performance was evaluated using three key metrics of MR radio-frequency (RF) coil performance: transmit efficiency, the variation of the transmit field (a measure of homogeneity), and the 10g averaged local specific absorption rate (SAR). These metrics are compared to those of the commonly used birdcage (BC) coil. The main advantage of the MM liner is the 29.6% reduction in maximum SAR normalized to transmit field relative to the BC coil, with comparable transmit efficiency and homogeneity. Thus, the liner can potentially replace the BC coil as an RF transmitter and provide an enhanced safety margin, or allow the use of faster, more SAR-aggressive imaging sequences.

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Section: Alternative Bc Sar Reduction Strategiesmentioning

confidence: 99%

Metamaterial Liner for MRI Excitation—Part 2: Design and Performance at 4.7T

2022

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“…This work introduces a new curved approach to coil design that is tailored specifically for chick embryo MR scans. Previous attempts in in vivo human or animal experiments have largely aimed to integrate a curved feature solely on one side of the coil [30] , [31] , [32] , [33] , mainly due to limited accessibility. By integrating a curved shape into a standard low-pass birdcage coil, SNR is improved while achieving extended coverage.…”

Section: Introductionmentioning

confidence: 99%

A Modified Quadrature Birdcage Coil Incorporated With a Curved Feature for In Ovo MR Imaging

Choi,

Bruch,

Hong

et al. 2024

IEEE Open J. Eng. Med. Biol.

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Goal: This study presents a novel MRI coil design approach explicitly tailored for chick embryo measurements, with the primary objective of improving sensitivity and coverage. Methods: The limitations posed by conventional birdcage coils were addressed by introducing a curvature feature into a standard coil. The performance of the modified coil was assessed using EM simulations and experimental evaluations, which were subsequently validated using a 7 T MRI scanner. A comparative analysis was conducted against a standard quadrature low-pass birdcage coil to evaluate key factors. Results: The proposed coil demonstrated improved SNR and uniformity, particularly in the proximity of the end-rings. These results were consistent with the findings obtained from the simulations. Conclusions: The use of our innovative birdcage coil design holds promise and offers practical potential for in ovo studies.

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