Edited Magnetic Resonance Spectroscopy Detects an Age-Related Decline in Nonhuman Primate Brain GABA Levels

Figure 2

The original GABA+ spectrum editing results: (a) the processed GABA-edited difference spectrum (EDIT-OFF − EDIT-ON = DIFF), which is the primary output of the GannetLoad module. Green spectrum is the one before frequency and phase correction, while the blue line is the one after frequency and phase correction. (b) Model fitting of GABA+ and Creatine spectrum peak: this plot represents the GABA+ signal modeling (GannetLoad output). The blue line is the actual GABA-edited spectrum while the red one is the model of best fit (using a simple Gaussian model by default). The residual is the black curve below the modeling plot. (c) Cr signal variation through the whole experiment; the -axis represents the frequency of Cr signal (ppm); the intensity registers with a color scale, so the Cr signal appears as “hot” stripe through the plot. The lower half line should be more evenly horizontal compared with the upper half strip due to the frequency and phase correction. (d) The bottom panel is the Cr signal from the OFF spectrum.

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