Phosphorus transversal relaxation times and metabolite concentrations in the human brain at 9.4 T.
NMR Biomed
; 35(10): e4776, 2022 10.
Article
en En
| MEDLINE
| ID: mdl-35607903
ABSTRACT
A method to estimate phosphorus (31 P) transversal relaxation times (T2 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. T2 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. T2 times of ATP and nicotinamide adenine dinucleotide (NAD) were shortest between 8 and 20 ms, followed by T2 s of inorganic phosphate between 25 and 50 ms, and phosphocreatine with a T2 of 100 ms. Phosphomonoesters and phosphodiesters had the longest T2 s of about 130 ms. The measured T2 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.
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1
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01-internacional
Banco de datos:
MEDLINE
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Fósforo
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Límite:
Humans
Idioma:
En
Revista:
NMR Biomed
Asunto de la revista:
DIAGNOSTICO POR IMAGEM
/
MEDICINA NUCLEAR
Año:
2022
Tipo del documento:
Article
País de afiliación:
Alemania