Figure 2.

Phantom results. (a.) Voxel placement. (b.) Spectra from all N_ent=10 schedule entries from a single MRSF acquisition, after summation of N_avg=20 averages. (c.) The normalized fingerprints of NAA, Cr and Cho from all N_rep=22 repetitions (mean±standard deviation). The similarity between different scans is so high that the outlines of the standard deviation can barely be seen. (d.) The mean±standard deviation of the residual for NAA, Cr, Cho, taken over N_rep=22 repetitions. All non-zero residuals are either within 1–2 standard deviations from zero, indicating the overall robustness of the dictionary fitting process. (e.) Box plots (median, inter-quartile range and whiskers) for $\Delta T_1$, the difference between the estimated and “true” T₁ in the phantom (as measured using a long inversion recovery experiment), from all N_rep=22 repetitions. The schedule’s precision (standard deviation) is reflected by the width of the boxplot, while its accuracy (bias) is reflected by its distance from the $\Delta T_1=0$ line. (f,g.) Boxplots for $\Delta T_2$ (as measured by a long multi-echo single voxel experiment) and ∆concentrations. (h.) Summed TE=35 ms schedule entries and corresponding LCModel fit from one of the 5-minute N_rep=22 repetitions. This fit was used to assess concentrations, as explained in the Methods section.