³¹P magnetization transfer magnetic resonance spectroscopy: assessing the activation induced change in cerebral ATP metabolic rates at 3 T

Chen, Chen; Stephenson, Mary C.; Peters, Andrew; Morris, Peter G.; Francis, Susan T.; Gowland, Penny A.

Abstract

Purpose: In vivo ³¹P MRS magnetization transfer (MT) provides a direct measure of neuronal activity at the metabolic level. This work aims to use functional ³¹P MRS-MT to investigate the change in cerebral ATP metabolic rates in healthy adults upon repeated visual stimuli.

Methods: A magnetization saturation transfer sequence with narrowband selective saturation of γ-ATP was developed for ³¹P MT experiments at 3 T.

Results: Using progressive saturation of γ-ATP, the intrinsic T1 relaxation times of phosphocreatine (PCr) and inorganic phosphate (Pi) at 3 T were measured to be 5.1±0.8 s and 3.0±1.4 s, respectively. Using steady-state saturation of γ-ATP, a significant 24±14% and 11±7% increase in the forward creatine kinase (CK) pseudo-first-order reaction rate constant, k₁, was observed upon visual stimulation in the first and second cycles respectively of a paradigm consisting of 10min-rest followed by 10min-stimulation, with the measured baseline k₁ being 0.35±0.04 s⁻¹. No significant changes in forward ATP synthase (ATPase) reaction rate, PCr/γ- ATP, Pi/γ-ATP, and NAD(H)/γ-ATP ratios, or intracellular pH were detected upon stimulation.

Conclusion: This work demonstrates the potential of studying cerebral bioenergetics using functional ³¹P MRS-MT to determine the change in the forward CK reaction rate at 3 T.

Citation

Chen, C., Stephenson, M. C., Peters, A., Morris, P. G., Francis, S. T., & Gowland, P. A. (2018). ³¹P magnetization transfer magnetic resonance spectroscopy: assessing the activation induced change in cerebral ATP metabolic rates at 3 T. Magnetic Resonance in Medicine, 79(1), 22-30. https://doi.org/10.1002/mrm.26663

• Journal Article Type: Article
• Acceptance Date: Feb 7, 2017
• Online Publication Date: Mar 16, 2017
• Publication Date: 2018-01
• Deposit Date: Feb 27, 2017
• Publicly Available Date: Mar 16, 2017
• Journal: Magnetic Resonance in Medicine
• Print ISSN: 0740-3194
• Electronic ISSN: 1522-2594
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• Volume: 79
• Issue: 1
• Pages: 22-30
• DOI: https://doi.org/10.1002/mrm.26663
• Keywords: Adenosine triphosphate (ATP) metabolism; Magnetization transfer; In vivo 31P magnetic resonance spectroscopy (MRS); Visual stimulation; Bioenergetics; Brain
• Public URL: https://nottingham-repository.worktribe.com/output/850990
• Publisher URL: http://onlinelibrary.wiley.com/doi/10.1002/mrm.26663/full
• Contract Date: Feb 27, 2017