TY - JOUR
T1 - Brain γ-aminobutyric acid measurement by proton double-quantum filtering with selective J rewinding
AU - Choi, Changho
AU - Coupland, Nicholas J.
AU - Hanstock, Christopher C.
AU - Ogilvie, Catherine J.
AU - Higgins, Andrea C M
AU - Gheorghiu, Dan
AU - Allen, Peter S.
PY - 2005/8
Y1 - 2005/8
N2 - An optimized single-shot proton double-quantum (DQ) filter for the quantification of γ-aminobutyric acid (GABA) levels in human brain is reported. It is demonstrated that creation of DQ coherences following dual-resonance-selective refocusing gives a theoretical editing efficiency of 50% for the detection of the GABA resonance at 3.01 ppm. The sequence times are optimized with both numerical and experimental analyses of the editing performance, giving an experimental editing efficiency of 42%. It is acknowledged that homocarnosine is partially coedited, leading to a 20% contribution to the edited signal; however, macromolecule contamination is negligible in vivo under these experimental conditions. The GABA concentration in human prefrontal cortex is estimated to be 0.8 ± 0.1 μmol/g (mean ± SD, n = 6), with reference to the internal standard creatine at 9 μmol/g.
AB - An optimized single-shot proton double-quantum (DQ) filter for the quantification of γ-aminobutyric acid (GABA) levels in human brain is reported. It is demonstrated that creation of DQ coherences following dual-resonance-selective refocusing gives a theoretical editing efficiency of 50% for the detection of the GABA resonance at 3.01 ppm. The sequence times are optimized with both numerical and experimental analyses of the editing performance, giving an experimental editing efficiency of 42%. It is acknowledged that homocarnosine is partially coedited, leading to a 20% contribution to the edited signal; however, macromolecule contamination is negligible in vivo under these experimental conditions. The GABA concentration in human prefrontal cortex is estimated to be 0.8 ± 0.1 μmol/g (mean ± SD, n = 6), with reference to the internal standard creatine at 9 μmol/g.
KW - Double-quantum filter
KW - Double-resonance selective refocusing
KW - Human brain
KW - Prefrontal cortex
KW - γ-aminobutyric acid (GABA)
UR - http://www.scopus.com/inward/record.url?scp=22744432671&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=22744432671&partnerID=8YFLogxK
U2 - 10.1002/mrm.20563
DO - 10.1002/mrm.20563
M3 - Article
C2 - 16032672
AN - SCOPUS:22744432671
SN - 0740-3194
VL - 54
SP - 272
EP - 279
JO - Magnetic resonance in medicine
JF - Magnetic resonance in medicine
IS - 2
ER -