A novel multifrequency-tuned transceiver array for human-brain ³¹P-MRSI at 7 T.

Area of Science:

• Magnetic Resonance Imaging
• Neuroimaging
• Metabolic Imaging

Background:

• ³¹P MR spectroscopy imaging (MRSI) at 7 Tesla offers superior signal-to-noise ratio (SNR) and spectral resolution for studying brain energy metabolism.
• Current 7T ³¹P MRSI requires complex dual-frequency coils for simultaneous proton (¹H) anatomical imaging and ³¹P metabolic imaging.
• Existing dual-frequency coils often involve intricate circuitry or multiple coil layers, posing design and cost challenges.

Purpose of the Study:

• To introduce a novel, simplified ³¹P-¹H dual-frequency radiofrequency coil design for 7T human brain MRSI.
• To evaluate the performance of this new coil, termed the double-tuned and double-matched (DODO) coil, against conventional coil setups.
• To demonstrate the DODO coil's efficacy in improving SNR and spectral quality for in vivo ³¹P MRSI.

Main Methods:

• Construction of an eight-element ³¹P-¹H dual-frequency DODO transceiver array.
• Comparative performance analysis against a standard quadrature-driven dual-tuned coil array (³¹P and ¹H elements).
• Evaluation using both phantom studies and in vivo human brain ³¹P MRSI at 7 Tesla.

Main Results:

• The DODO transceiver array successfully achieved high spatiotemporal resolution ³¹P MRSI (2.5-cc voxel, 22-min scan) covering the entire human brain.
• Excellent SNR was obtained for mapping key cerebral metabolites, including phosphocreatine and adenosine triphosphate.
• Significant SNR improvements were observed: over 5-fold gain in peripheral regions and over 2-fold gain in central brain regions compared to the conventional coil.

Conclusions:

• The novel ³¹P-¹H DODO coil offers a simple, cost-effective, and high-performance solution for 7T human brain ³¹P MRSI.
• This design overcomes the complexity of previous dual-frequency coils without compromising imaging performance.
• The enhanced SNR and spectral quality provided by the DODO coil will significantly advance ³¹P MRSI applications in neuroscience and clinical research.