In vivo measurement of glycine with short echo-time 1H MRS in human brain at 7 T.
MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE 2008;
22:1-4. [PMID:
18949497 DOI:
10.1007/s10334-008-0152-0]
[Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2008] [Revised: 09/30/2008] [Accepted: 10/03/2008] [Indexed: 10/21/2022]
Abstract
OBJECT
To determine whether glycine can be measured at 7 T in human brain with (1)H magnetic resonance spectroscopy (MRS).
MATERIALS AND METHODS
The glycine singlet is overlapped by the larger signal of myo-inositol. Density matrix simulations were performed to determine the TE at which the myo-inositol signal was reduced the most, following a single spin-echo excitation. (1)H MRS was performed on an actively shielded 7 T scanner, in five healthy volunteers.
RESULTS
At the TE of 30 ms, the myo-inositol signal intensity was substantially reduced. Quantification using LCModel yielded a glycine-to-creatine ratio of 0.14 +/- 0.01, with a Cramér-Rao lower bound (CRLB) of 7 +/- 1%. Furthermore, quantification of metabolites other than glycine was possible as well, with a CRLB mostly below 10%.
CONCLUSION
It is possible to detect glycine at 7 T in human brain, at the short TE of 30 ms with a single spin-echo excitation scheme.
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