Phosphorus transversal relaxation times and metabolite concentrations in the human brain at 9.4 T.

Autor: Dorst J; High-Field MR Center, Max Planck Institute for Biological Cybernetics, Tübingen, Germany.; International Max Planck Research School for Cognitive and Systems Neuroscience (IMPRS), University of Tübingen, Tübingen, Germany., Borbath T; High-Field MR Center, Max Planck Institute for Biological Cybernetics, Tübingen, Germany.; Faculty of Science, University of Tübingen, Tübingen, Germany., Ruhm L; High-Field MR Center, Max Planck Institute for Biological Cybernetics, Tübingen, Germany.; International Max Planck Research School for Cognitive and Systems Neuroscience (IMPRS), University of Tübingen, Tübingen, Germany., Henning A; High-Field MR Center, Max Planck Institute for Biological Cybernetics, Tübingen, Germany.; Advanced Imaging Research Center, UT Southwestern Medical Center, Dallas, Texas, USA.
Jazyk: angličtina
Zdroj: NMR in biomedicine [NMR Biomed] 2022 Oct; Vol. 35 (10), pp. e4776. Date of Electronic Publication: 2022 Jun 05.
DOI: 10.1002/nbm.4776
Abstrakt: A method to estimate phosphorus ( 31 P) transversal relaxation times (T 2 s) of coupled spin systems is demonstrated. Additionally, intracellular and extracellular pH and relaxation-corrected metabolite concentrations are reported. Echo time (TE) series of 31 P metabolite spectra were acquired using stimulated echo acquisition mode (STEAM) localization. Spectra were fitted using LCModel with accurately modeled Versatile Simulation, Pulses and Analysis (VeSPA) basis sets accounting for J-evolution of the coupled spin systems. T 2 s were estimated by fitting a single exponential two-parameter model across the TE series. Fitted inorganic phosphate frequencies were used to calculate pH, and estimated relaxation times were used to determine the relaxation-corrected brain metabolite concentrations on an assumption of 3 mM γ-ATP. The method was demonstrated in healthy human brain at a field strength of 9.4 T. T 2 times of ATP and nicotinamide adenine dinucleotide (NAD) were shortest between 8 and 20 ms, followed by T 2 s of inorganic phosphate between 25 and 50 ms, and phosphocreatine with a T 2 of 100 ms. Phosphomonoesters and phosphodiesters had the longest T 2 s of about 130 ms. The measured T 2 s are comparable with literature values and fit in a decreasing trend with increasing field strengths. Calculated pHs and metabolite concentrations are also comparable with literature values.
(© 2022 The Authors. NMR in Biomedicine published by John Wiley & Sons Ltd.)
Databáze: MEDLINE
Externí odkaz: