Article Figures & Data
Figures
- FIG 1.
Illustrated MRSI workflow. After acquiring 2D MRSI and an associated T1WI-based segmentation, one spectrum for each region was generated by combining the spectra for all overlapping voxels in a weighted average based on overlap contribution (Equation). The regionally-weighted spectra were subsequently fit using LCModel to compute metabolite peaks, resulting in one metabolite ratio computed per participant per region. Of note, the pictured MRSI grid is provided only for illustrative purposes and does not represent collected data.
- FIG 2.
Maps of weights used to compute weighted average spectra for WM and deep GM in a representative participant. Each voxel is colored to represent its percent contribution to the tissue-weighted spectra as well as the corresponding voxel-wise volume fraction in parentheses.
- FIG 3.
Mean regionally weighted spectra with 95% confidence intervals across participants from 0.2 to 4.0 ppm. Spectra were extracted for each region for each participant from LCModel and plotted after baseline subtraction. a.u. indicates arbitrary units.
- FIG 4.
Differences in NAA/Cr in T1D by region. A, The uncalibrated NAA/Cr ratios from the regionally weighted spectra are shown across participants. B, P values of statistical comparisons between WM and deep GM as a whole and the individual deep nuclei. C, P values of contralateral comparisons in deep GM nuclei. D, P values of ipsilateral comparisons in deep GM nuclei. Statistical significance between regions was determined with pair-wise Wilcoxon signed-rank tests after false discovery rate correction (en dash indicates not tested; ns, not significant; single asterisk, P < .05; double asterisks, P < .005; triple asterisks, P < .0005). RC indicates right caudate; RBG, right basal ganglia; RTH, right thalamus; LC, left caudate; LBG, left basal ganglia; LTH, left thalamus; DGM, deep GM.
- FIG 5.
Associations of NAA/Cr in WM with T1D complications. The calibrated NAA/Cr ratios in WM are shown plotted against HbA1c, DKA status, and their interaction. Data points are colored by site with the symbol denoting the participant’s DKA status.
Tables
Site A Site B Site C Overall Sample size (No.) 10 11 4 25 Age (yr) (mean) 10.6 (SD, 1.1) 10.5 (SD, 2.7) 8.5 (SD, 1.3) 10.2 (SD, 2.0) Sex, female (No.) 7 (70%) 5 (45%) 3 (75%) 15 (60%) Duration (yr) (mean) 2.6 (SD, 2.3) 4.6 (SD, 3.3) 0.3 (SD, 0.1) 3.1 (SD, 3.0) HbA1c (%) (mean) 9.5 (SD, 3.2) 8.5 (SD, 1.9) 6.2 (SD, 0.9) 8.5 (SD, 2.6) DKA at onset (No.) 5 (50%) 9 (82%) 0 (0%) 14 (56%) Race (No) White 7 (70%) 8 (73%) 4 (100%) 19 (76%) Black/African American 2 (20%) 1 (9%) 0 (0%) 3 (12%) Multiracial (black/white) 0 (0%) 1 (9%) 0 (0%) 1 (4%) Other 1 (10%) 1 (9%) 0 (0%) 2 (8%) - Table 2:
Effect sizes, Akaike Information Criterion, and adjusted R2 for forward model selection of NAA/Cr in WM and deep GM with T1D covariates
Tissue HbA1c DKA HbA1c x DKA Age Sex Duration Akaike aR2 WM –0.086a – – – – – 17.581 0.291 –0.080b –0.095 – – – – 19.083 0.273 –0.171a,c –1.142b,c 0.130b,c – – – 15.373c 0.394c –0.169a –1.156b 0.131b –0.009 – – 17.298 0.365 –0.187a –1.209b 0.141b –0.001 0.175 – 17.086 0.389 –0.187a –1.267b 0.144b –0.005 0.189 0.012 18.799 0.362 Deep GM –0.016c – – – – – –29.356c 0.061c –0.018 0.034 – – – – –27.785 0.034 –0.027 –0.065 0.012 – – – –26.087 –0.001 –0.029 –0.043 0.010 0.011 – – –24.800 –0.023 –0.027 –0.035 0.009 0.010 –0.018 – –22.922 –0.075 –0.028 –0.086 0.011 0.007 –0.005 0.011 –22.194 –0.079
Jump to section
Related Articles
Cited By...
- No citing articles found.