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. Author manuscript; available in PMC: 2016 Apr 30.
Published in final edited form as: Psychiatry Res. 2015 Feb 3;232(1):65–70. doi: 10.1016/j.pscychresns.2015.01.009

Figure 1.

Figure 1

Striatal Subregions and Associated Sample 1H MR Spectral Data. [A] Coronal and [B] axial localizer images showing the size and location of the volume of interest (large white box) pre-localized with the PRESS method. The spectroscopic imaging (SI) slice thickness was 20 mm, field of view 16 cm, with the slice positioned coronally anterior to the anterior commissure. The coronal view, [A], is overlaid with a grid of voxels that cover the striatum and its subregions. Within this grid, three individual voxels (0.8 × 0.8 × 2.0 cm3) were positioned to contain the dorsal caudate, dorsal putamen, and ventral striatum. The multi-voxel PRESS data set was acquired in 20 min using TE/TR 80/1500 ms, 20×20 phase-encoding (PE) steps, 2 excitations per PE. The arrows point to sample 1H spectra recorded from these three striatal voxels, labeled as follows in panel [C]: (a) dorsal caudate; (b) dorsal putamen; and (c) ventral striatum; Shown left-to-right in each spectrum are the resonances for total choline (tCho), total creatine (tCr), N-acetyl-L-aspartate (NAA, methylene), uncontaminated glutamate (Glu), and NAA (methyl); (d) A nonlinear least-squares best-fit spectrum obtained by fitting the experimental spectrum in (c) to a sum of pseudo-Voigt lineshape functions in the frequency domain; (e) The residuals of the difference between (d) and (e). The fitting procedure yields areas under the metabolite resonances, which are proportional to concentrations.