Improvement of resolution for brain coupled metabolites by optimized 1H MRS at 7 T
| Autor: | Elizabeth A. Maher, Aditya Patel, Lana G. Kaiser, Ivan E. Dimitrov, Carlos A. Amezcua, Deborah Douglas, Changho Choi |
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| Rok vydání: | 2010 |
| Předmět: |
Adult
Male Magnetic Resonance Spectroscopy Resolution (mass spectrometry) Phantoms Imaging Chemistry Glutamine Brain Glutamic Acid Glutathione In vivo tests Young Adult chemistry.chemical_compound Nuclear magnetic resonance Yield (chemistry) Healthy volunteers Humans Molecular Medicine Female Radiology Nuclear Medicine and imaging Spectral fitting Spectroscopy |
| Zdroj: | NMR in Biomedicine. 23:1044-1052 |
| ISSN: | 0952-3480 |
| Popis: | Resolution enhancement for glutamate (Glu), glutamine (Gln) and glutathione (GSH) in the human brain by TE-optimized point-resolved spectroscopy (PRESS) at 7 T is reported. Sub-TE dependences of the multiplets of Glu, Gln, GSH, γ-aminobutyric acid (GABA) and N-acetylaspartate (NAA) at 2.2–2.6 ppm were investigated with density matrix simulations, incorporating three-dimensional volume localization. The numerical simulations indicated that the C4-proton multiplets can be completely separated with (TE1, TE2) = (37, 63) ms, as a result of a narrowing of the multiplets and suppression of the NAA 2.5 ppm signal. Phantom experiments reproduced the signal yield and lineshape from simulations within experimental errors. In vivo tests of optimized PRESS were conducted on the prefrontal cortex of six healthy volunteers. In spectral fitting by LCModel, Cramer–Rao lower bounds (CRLBs) of Glu, Gln and GSH were 2 ± 1, 5 ± 1 and 6 ± 2 (mean ± SD), respectively. To evaluate the performance of the optimized PRESS method under identical experimental conditions, stimulated-echo spectra were acquired with (TE, TM) = (14, 37) and (74, 68) ms. The CRLB of Glu was similar between PRESS and short-TE stimulated-echo acquisition mode (STEAM), but the CRLBs of Gln and GSH were lower in PRESS than in both STEAM acquisitions. Copyright © 2010 John Wiley & Sons, Ltd. |
| Databáze: | OpenAIRE |
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