Dual resonant birdcage coils for1H detected13C microscopic imaging at 11.7 T

Hudson, Alex M. J.; Köckenberger, Walter; Bowtell, Richard

doi:10.1007/bf02601839

Cited by 3 publications

(4 citation statements)

References 14 publications

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“…6. The resulting data are in good agreement with a similar map acquired using PRAWN-based CYCLCROP in conjunction with a spin-warp imaging procedure (21). The EPI data were, however, acquired in just 64 s, compared with a 68 min acquisition time for the spin-warp sequence.…”

Section: Field Mapping Using the Cyclcrop-epi Sequencementioning

confidence: 54%

1H Detected 13C Echo Planar Imaging

Hudson

Köckenberger

Heidenreich

et al. 2002

Journal of Magnetic Resonance

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Section: Field Mapping Using the Cyclcrop-epi Sequencementioning

confidence: 54%

1H Detected 13C Echo Planar Imaging

Hudson

Köckenberger

Heidenreich

et al. 2002

Journal of Magnetic Resonance

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“…[23][24][25][26][27][28][29] In 1989, Joseph and Lu built a "birdcage" volume coil to generate homogeneous RF magnetic fields at two desired resonant frequencies for multinuclear NMR imaging, 30 and since then various double-tuned birdcage imaging coils have been reported. [31][32][33][34][35][36][37][38][39][40][41] Among them, a quadrature double-tuned birdcage coil was developed to enable the birdcage coils in X-nuclear MRSI applications. 33 With the rapid development and utilization of high/ultrahigh magnetic field scanners in research and clinical applications, a need for efficient high-frequency RF coils has emerged.…”

Section: Introductionmentioning

confidence: 99%

“…Using a similar circuit concept, several other surface coils with multiple resonant frequencies have been designed and reported 23–29 . In 1989, Joseph and Lu built a “birdcage” volume coil to generate homogeneous RF magnetic fields at two desired resonant frequencies for multinuclear NMR imaging, 30 and since then various double‐tuned birdcage imaging coils have been reported 31–41 . Among them, a quadrature double‐tuned birdcage coil was developed to enable the birdcage coils in X‐nuclear MRSI applications 33 .…”

Section: Introductionmentioning

confidence: 99%

Dual‐frequency resonant coil design for low‐γ X‐nuclear and proton magnetic resonance imaging at ultrahigh fields

Zhang

Zhu

et al. 2023

NMR in Biomedicine

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Low‐γ X‐nuclear MRS and imaging have played a key role in studying metabolism and physiopathology, especially at ultrahigh fields. We design and demonstrate a novel and simple dual‐frequency RF resonant coil that can operate at both low‐γ X‐nuclear and proton frequencies. The dual‐frequency resonant coil comprises an LC coil loop and a tuning‐matching circuit bridged by two short wires of the desired length to generate two resonant modes: one for proton MRI and the other for low‐γ X‐nuclear MRS imaging with a large difference in their Larmor frequencies at ultrahigh fields. The coil parameters for the desired coil size and resonant frequencies can be determined via numerical simulations based on LC circuit theory. We designed, constructed, and evaluated several prototype surface coils and quadrature array coils for 1H and 2H or 17O imaging, with small‐sized (diameter ≤ 5 cm) coils evaluated using a 16.4 T animal scanner, and a large‐sized (15 cm diameter) coil on a 7 T human scanner. All coils could be tuned/matched and driven in the single coil or array coil mode to the resonant frequencies of 1H (698 and 298 MHz), 2H (107 and 45.8 MHz), or 17O (94.7 and 40.4 MHz) for imaging measurements and evaluation at 16.4 and 7 T, respectively. The dual‐frequency resonant coil or array provides adequate detection sensitivity for 1H MRI and excellent performance for low‐γ X‐nuclear MRS imaging applications, and excellent coil decoupling efficiency between the array coils at both resonant frequencies with an optimal geometric overlap. It provides a simple, cost‐effective dual‐frequency RF coil solution to perform low‐γ X‐nuclear MRS imaging for preclinical and human applications, especially at ultrahigh fields.

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“…A double-tuned coil can also be constructed using separate coils, such as two birdcage coils in co-axial configuration [20][21][22][23] or concentric loops. 24,25 Although each coil resonates at a different frequency, mutual coupling can cause interference between the coils due to induced current between the loops.…”

Section: Introductionmentioning

confidence: 99%

Scalable and modular 8‐channel transmit and 8‐channel flexible receive coil array for ¹⁹F MRI of large animals

Özen

Spreter

Schimpf

et al. 2022

Magnetic Resonance in Med

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Purpose To introduce an RF coil system consisting of an 8‐channel transmit (Tx) and 8‐channel receive (Rx) coil arrays for 19F MRI of large animals. Methods The Tx efficiency and homogeneity of the 8‐element loop coil array (loop size: 6 × 15 cm2) were simulated for two different pig models rendered from MR images. An 8‐channel Rx coil array consisting of a flexible 6‐channel posterior and a 2‐channel planar anterior array was designed to fit on the abdomen of an average‐sized pig in supine position. Measurements were performed in a grid phantom and ex vivo on a pig model with perfluoroctylbromide (PFOB)–filled tubes inserted in the thorax. Results Measured and simulated Tx efficiency and homogeneity for the 8‐channel and 5‐channel arrays were in good agreement: 1.87 ± 0.22μT/√kW versus 1.96 ± 0.29μT/√kW, and 2.29 ± 0.39μT/√kW versus 2.41 ± 0.37μT/√kW. An isolation of 38 ± 8 dB is achieved between the 19F Tx and Rx elements, and over 30 dB between the 1H and 19F elements. The PFOB‐filled vials could be clearly identified within the cadaver abdomen with an SNR of 275 ± 51 for a 3D gradient‐echo sequence with 2‐mm isotropic resolution and 12 averages, acquired in 9:52 min:s. Performance of the Tx array was robust against phase and amplitude mismatches at the input ports. Conclusions A modular and scalable Tx array offers improved Tx efficiency in 19F MRI of large animals with various sizes. Although conventional birdcage coils have superior Tx efficiency within the target region of interest, scalability of the Tx array to animal size is a major benefit. The described 19F coil provides homogeneous excitation and high sensitivity detection in large pig models.

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Dual resonant birdcage coils for1H detected13C microscopic imaging at 11.7 T

Cited by 3 publications

References 14 publications

1H Detected 13C Echo Planar Imaging

1H Detected 13C Echo Planar Imaging

Dual‐frequency resonant coil design for low‐γ X‐nuclear and proton magnetic resonance imaging at ultrahigh fields

Scalable and modular 8‐channel transmit and 8‐channel flexible receive coil array for ¹⁹F MRI of large animals

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Dual resonant birdcage coils for1H detected13C microscopic imaging at 11.7 T

Cited by 3 publications

References 14 publications

1H Detected 13C Echo Planar Imaging

1H Detected 13C Echo Planar Imaging

Dual‐frequency resonant coil design for low‐γ X‐nuclear and proton magnetic resonance imaging at ultrahigh fields

Scalable and modular 8‐channel transmit and 8‐channel flexible receive coil array for 19F MRI of large animals

Contact Info

Product

Resources

About

Scalable and modular 8‐channel transmit and 8‐channel flexible receive coil array for ¹⁹F MRI of large animals