Correction: Koush, Y.; Elliott, M.A. and Mathiak, K. Single Voxel Proton Spectroscopy for Neurofeedback at 7 Tesla. Materials 2011, 4, 1548–1563
- 1.
- Figure 1, p. 1551 should be with the correct time and frequency axes:Figure 1. Spectral processing of the single voxel spectroscopic data. (a) Raw (blue) and processed (red) magnitude free induction decay functions (FIDs); (b) Raw (blue) and processed (red) magnitude spectra. Note that graphics and spectra were normalized to their maximum values for comparison purposes and the panels are scaled differently.
- 2.
- Figure 2, p. 1552 should be with the correct time axis. The loptim should be 19.7 ms; not 0.078 s.
- 3.
- Last paragraph, lines 5–7, p. 1554: For the following sentence the bandwidth should be 2 kHz; not 1 kHz. The acquisition duration = 256 ms should be specified.
- A spin-echo SVPS protocol was also acquired with 300 repetitions, TE/TR = 20/1000 ms, flip angle α = 90°, average voxel size 10 × 10 × 10 mm3, bandwidth = 2 kHz, acquisition duration = 256 ms.
- 4.
- Second paragraph, lines 3–5, p. 1556: The sentence with citations [51,52] should be modified to “the absolute T2* values in some subjects differ from those expected”; not “the absolute T2* values differ from those expected”.
- Although the T2* values show detectable dynamic change in the measured regions due to the BOLD activation, the absolute T2* values in some subjects differ from those expected at 7T for venous blood (T2* < 5 ms), gray matter (T2* ~ 21 ms), and arterial blood (T2* ~ 40 ms) [51,52].
- 5.
- Second paragraph, lines 5–7, p. 1556: The T2* estimates should be in ms, PMC (T2*offl = 21.1 ± 0.6 ms), PMC NF (T2*nf = 21.8 ± 0.7 ms), and VC (T2*offl = 16.8 ± 0.5 ms); not in arbitrary units, PMC (T2*offl = 84.2 ± 2.5), PMC NF (T2*nf = 87.3 ± 2.6), and VC (T2*offl = 67.0 ± 2.1).
- The baseline T2* values averaged across the four subjects were: PMC (T2*offl = 21.1 ± 0.6 ms), PMC NF (T2*nf = 21.8 ± 0.7 ms), and VC (T2*offl = 16.8 ± 0.5 ms).
- 6.
- Figure 3, p. 1556: The T2* axis should be modified. The last sentence of the Figure 3 description should be “Acquired time series show significant variability between subjects and regions of interest (ROIs) T2* values.”; not the “Acquired time series show significant variability between subjects and regions of interest (ROIs) and overall higher than expected T2* values.”. The sentence of the Figure 3 description ‘These large calculated T2* values indicate that the measured signal contains spin-echo components from the SVS excitation scheme and partial volume effects with cerebro-spinal fluid–particularly in some PMC ROIs.’ should be removed.Figure 3. Functional single-voxel proton spectroscopy (fSVPS)-estimated T2* time series. (a) The primary motor cortex (PMC); (b) PMC in real time (PMC NF); and (c) Visual cortex (VC) functional single-voxel proton spectroscopy (fSVPS) time series (processed) are displayed for four control subjects. Acquired time series show significant variability between subjects and regions of interest (ROIs) T2* values.
- 7.
- Figure 6, p. 1558 should be with the correct time axes. The PMC loptim should be 50.2 ms; not 200 ms. The VC loptim should be 19.7 ms; not 78 ms:Figure 6. Optimal linear regression length. Experimental statistic (t-value) depends on the applied linear regression length and reveals an optimum duration, loptim, here shown in a typical example for (a) the PMC (blue dot; loptim = 50.2 ms, t = 17.0, p < 0.001) and (b) the VC condition (blue dot; loptim = 19.7 ms, t = 19.12, p < 0.001). Note that panels are scaled differently.
- 8.
- Second paragraph, lines 2–3, p. 1558. The maximum t-value attained should be 70 ms; not 220 ms.
- The maximum t-value (Figure 6) was specific for selected ROI and time from the beginning of FID acquisition. Thus, with the chosen TE = 20 ms, the maximal t-value attained was around 70 ms after the first excitation pulse in the PMC example.
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Koush, Y.; Elliott, M.A.; Mathiak, K. Correction: Koush, Y.; Elliott, M.A. and Mathiak, K. Single Voxel Proton Spectroscopy for Neurofeedback at 7 Tesla. Materials 2011, 4, 1548–1563. Materials 2011, 4, 2057-2060. https://doi.org/10.3390/ma4112057
Koush Y, Elliott MA, Mathiak K. Correction: Koush, Y.; Elliott, M.A. and Mathiak, K. Single Voxel Proton Spectroscopy for Neurofeedback at 7 Tesla. Materials 2011, 4, 1548–1563. Materials. 2011; 4(11):2057-2060. https://doi.org/10.3390/ma4112057
Chicago/Turabian StyleKoush, Yury, Mark A. Elliott, and Klaus Mathiak. 2011. "Correction: Koush, Y.; Elliott, M.A. and Mathiak, K. Single Voxel Proton Spectroscopy for Neurofeedback at 7 Tesla. Materials 2011, 4, 1548–1563" Materials 4, no. 11: 2057-2060. https://doi.org/10.3390/ma4112057