J-difference editing of gamma-aminobutyric acid (GABA): simulated and experimental multiplet patterns.
Magn Reson Med
; 70(5): 1183-91, 2013 Nov.
Article
en En
| MEDLINE
| ID: mdl-23213033
ABSTRACT
PURPOSE:
To investigate factors that influence the multiplet pattern observed in J-difference editing of gamma-aminobutyric acid (GABA).METHODS:
Density matrix simulations were applied to investigate the shape of the 3 ppm GABA multiplet as a function of the editing sequence's slice-selective refocusing pulse properties, in particular bandwidth, transition width, and flip angle. For comparison to the calculations, experimental measurements were also made at 3 T on a 10 mM GABA solution using the MEGA-PRESS sequence at various refocusing pulse flip angles.RESULTS:
Good agreement was found between experiments and simulations. The edited multiplet consists of two outer lines of slightly unequal intensity due to strong coupling, and a smaller central line, the result of the unequal J-couplings between the C4 and C3 protons. The size of the center peak increases with increasing slice-selective refocusing pulse transition width, and deviation of the flip angle from 180°.CONCLUSION:
The 3 ppm GABA multiplet pattern observed in the MEGA-PRESS experiment depends quite strongly on the properties of the slice-selective refocusing pulses used. Under some circumstance, the central peak can be quite large; this does not necessarily indicate inefficient editing, or a subtraction artifact, but should be recognized as a property of the pulse sequence itself.Palabras clave
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Algoritmos
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Reconocimiento de Normas Patrones Automatizadas
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Espectroscopía de Resonancia Magnética
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Ácido gamma-Aminobutírico
/
Modelos Químicos
Tipo de estudio:
Diagnostic_studies
/
Prognostic_studies
Idioma:
En
Revista:
Magn Reson Med
Asunto de la revista:
DIAGNOSTICO POR IMAGEM
Año:
2013
Tipo del documento:
Article
País de afiliación:
Reino Unido