Abstract：
PURPOSE:While PRESS is often employed to measure glutamate concentrations, MEGA-PRESS enables simultaneous Glx (glutamate and glutamine) and GABA measurements. This study aimed to compare validation, repeatability, and concordance of different approaches for glutamate quantification at 3T to aid future studies in their selection of the appropriate sequence and quantification method. MATERIALS AND METHODS:Nine phantoms with different glutamate and glutamine concentrations and five healthy participants were scanned twice to assess respectively the validation and repeatability of measurements with PRESS and MEGA-PRESS. To assess concordance between the different methods, results from 95 human participants were compared. PRESS, MEGA-PRESS (i.e. difference), and the MEGA-PRESS OFF spectra were analyzed with both LCModel and Gannet. RESULTS:In vitro, excellent agreement was shown between actual and measured glutamate concentrations for all measurements (r>0.98). In vivo CVs were better for PRESS (2.9%) than MEGA-PRESS (4.9%) and MEGA-PRESS OFF (4.2%). However, the concordance between the sequences was low (PRESS and MEGA-PRESS OFF, r=0.3) to modest (MEGA-PRESS versus MEGA-PRESS OFF, r=0.8). CONCLUSION:Both PRESS and MEGA-PRESS can be employed to measure in vivo glutamate concentrations, although PRESS shows a better repeatability. Comparisons between in vivo glutamate measures of different sequences however need to be interpreted cautiously.
journal_name
Magn Reson Imagingjournal_title
Magnetic resonance imagingauthors
van Veenendaal TM,Backes WH,van Bussel FCG,Edden RAE,Puts NAJ,Aldenkamp AP,Jansen JFAdoi
10.1016/j.mri.2017.12.029subject
Has Abstractpub_date
2018-05-01 00:00:00pages
107-114eissn
0730-725Xissn
1873-5894pii
S0730-725X(17)30303-Xjournal_volume
48pub_type
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journal_title：Magnetic resonance imaging
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