A Novel 9-Channel 1H, 3-Channel 31P Radiofrequency Coil for Interleaved Multinuclear Studies of Human Calf Muscle at 7 T

TY - JOUR

T1 - A Novel 9-Channel 1H, 3-Channel 31P Radiofrequency Coil for Interleaved Multinuclear Studies of Human Calf Muscle at 7 T

AU - Cap, Veronika

AU - dos Santos, Vasco Rafael Rocha

AU - Repnin, Kostiantyn

AU - Soanca, Onisim

AU - Laistler, Elmar

AU - Wolf, Peter

AU - Kemp, Graham J.

AU - Frass-kriegl, Roberta

AU - Meyerspeer, Martin

N1 - Publisher Copyright: © 2026 The Author(s). Magnetic Resonance in Medicine published by Wiley Periodicals LLC on behalf of International Society for Magnetic Resonance in Medicine.

PY - 2026/5

Y1 - 2026/5

N2 - Purpose To develop a double-tuned calf coil with excellent 1H and 31P performance to study muscle physiology by interleaved 1H/31P MRS and parallel imaging at 7 T.Methods The coil combines three 1H transceive dipoles, six 1H receive-only loops and three 31P transceive loops, arranged in a nested, half-cylindrical layout. Several different decoupling mechanisms were implemented to limit electromagnetic interactions within the 1H and 31P arrays, between transmit and receive elements as well as 1H-31P cross-coupling. A custom housing was designed for mechanical stability and ease of use. The 1H and 31P performance were investigated on phantoms and demonstrated in vivo in an exemplary measurement with interleaved, localized 1H/31P MRS in the gastrocnemius muscle of a healthy subject at rest, during exercise and recovery.Results On phantoms, compared to a double-tuned reference coil, the new coil showed 2.8-fold higher 1H SNR, a stronger and more homogenous 1H transmit field, and 27% lower 31P SNR. It enabled four-fold GRAPPA acceleration. In vivo the CH2 resonance of creatine and PCr were fitted from the unaveraged 1H and 31P spectra, which resulted in time courses with closely matching depletion and recovery constants.Conclusion These results highlight the coil's suitability for the target application of advanced metabolic calf muscle studies. Its high 1H performance will enable 1H MRS acquisitions with improved spatial and temporal resolution and enable the implementation of MRS sequences that had previously been limited by insufficient SNR, which will generate new insights into muscle physiology.

AB - Purpose To develop a double-tuned calf coil with excellent 1H and 31P performance to study muscle physiology by interleaved 1H/31P MRS and parallel imaging at 7 T.Methods The coil combines three 1H transceive dipoles, six 1H receive-only loops and three 31P transceive loops, arranged in a nested, half-cylindrical layout. Several different decoupling mechanisms were implemented to limit electromagnetic interactions within the 1H and 31P arrays, between transmit and receive elements as well as 1H-31P cross-coupling. A custom housing was designed for mechanical stability and ease of use. The 1H and 31P performance were investigated on phantoms and demonstrated in vivo in an exemplary measurement with interleaved, localized 1H/31P MRS in the gastrocnemius muscle of a healthy subject at rest, during exercise and recovery.Results On phantoms, compared to a double-tuned reference coil, the new coil showed 2.8-fold higher 1H SNR, a stronger and more homogenous 1H transmit field, and 27% lower 31P SNR. It enabled four-fold GRAPPA acceleration. In vivo the CH2 resonance of creatine and PCr were fitted from the unaveraged 1H and 31P spectra, which resulted in time courses with closely matching depletion and recovery constants.Conclusion These results highlight the coil's suitability for the target application of advanced metabolic calf muscle studies. Its high 1H performance will enable 1H MRS acquisitions with improved spatial and temporal resolution and enable the implementation of MRS sequences that had previously been limited by insufficient SNR, which will generate new insights into muscle physiology.

KW - X-nucleus

KW - Magnetic resonance imaging

KW - Magnetic resonance spectroscopy

KW - Muscle physiology

KW - Radiofrequency coil

KW - Ultra-high field

UR - https://www.webofscience.com/api/gateway?GWVersion=2&SrcApp=meduni_vienna_pure&SrcAuth=WosAPI&KeyUT=WOS:001652608700001&DestLinkType=FullRecord&DestApp=WOS_CPL

U2 - 10.1002/mrm.70249

DO - 10.1002/mrm.70249

M3 - Article

C2 - 41486100

SN - 0740-3194

VL - 95

SP - 3008

EP - 3020

JO - Magnetic Resonance in Medicine

JF - Magnetic Resonance in Medicine

IS - 5

ER -