Figure 2.
(A) Representative single voxel MR spectra of GSH from the motor cortex (3.5 × 2.5 × 2.3 cm3) of a subject with ALS using MEGA-PRESS (TE = 68 ms, TR = 2 s, 512 averages, editing pulse at 4.56 ppm for edit on and at 7.5 ppm for edit off) at 3 T. The bottom spectrum is shown without processing. Slight frequency drifts over time lead to small subtraction artifacts as can be seen for NAA (red arrow). The top spectrum shows the same spectrum as below after the individual transients are frequency aligned leading to a clean, flat baseline. Both spectra are shown with 1 Hz exponential line broadening. (B) GSH MRSI measured from the fronto-parietal region of the human brain using the doubly selective MQF editing sequence (TE = 115 ms, TR = 1.5 s, matrix size = 8 × 8, nominal voxel size = 1.25 × 1.25 × 3.0 cm3, field of view = 20 cm, and scan time = 16 min) at 3 T. All spectra were processed with 2 Hz exponential line broadening and are shown in the range from 3.6 to 2.2 ppm (adapted from Reference125).