Subtraction Artifacts and Frequency (Mis-)Alignment in J-Difference GABA Editing
Subtraction Artifacts and Frequency (Mis-)Alignment in J-Difference GABA Editing
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DOI：
10.1002/jmri.23923
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发表时间：
2013-10-01
影响因子：
4.4
通讯作者：
Edden, Richard A. E.
中科院分区：
文献类型：
--
作者：
Evans, C. John;Puts, Nicolaas A. J.;Edden, Richard A. E.
PurposeTo compare the repeatability of -aminobutyric acid (GABA) measurements using J-difference editing, before and after spectral realignmenta technique which has previously been demonstrated to improve the quality of J-difference GABA spectra.Materials and MethodsWe performed in vivo measurements in three brain regions (occipital, sensorimotor, and dorsolateral prefrontal cortex [DLPFC]), and analyzed these using alternative alignment approaches to evaluate the impact of alignment on repeatability: Independent alignment (aligning each subspectrum independently) and Pairwise alignment (aligning each on and off subspectrum as a pair) were compared.ResultsPairwise alignment improved the group mean coefficient of variation in all regions; 0.4% in occipital, 1.1% in sensorimotor, and 1.1% in DLPFC. Independent alignment resulted in subtraction artifacts in the majority of cases, and increased the coefficient of variation in the DLPFC by 9.4%. Simulations demonstrate that the GABA quantification error in datasets with high B-0 drift, is 4.5% without alignment, but
