Table 2. Group comparisons of quantitative imaging measures.
| Group mean values (SD) | Pairwise Comparisons (performed when ANCOVA showed between groups difference). | ||||||
|---|---|---|---|---|---|---|---|
| Control | MS | NMO | ANCOVA F Score (p) | NMO vs Control | MS vs Control | NMO vs MS | |
| Cross-sectional normalized brain volume/ mm3 | 1431785 (75185) | 1432448 (82061) | 1440255 (66069) | 0.269 (0.765) | NS | NS | NS |
| Cross-sectional average thalamic volume/ mm3 | 9864.9 (602.5) | 8749.6 (866.1) | 9991.4 (552.7) | 10.34 (<0.001) * | NS | p<0.001 * | p<0.001 * |
| Cross-sectional cervical spinal cord volume of NAT/ mm3 | 2945.7 (148.5) | 2684.3 (252.3) | 2848.7 (131.8) | 5.48 (0.003) * | NS | p = 0.001 * | p = 0.041 * |
| DTI of NAWM (FA) | 0.473 (0.015) | 0.443 (0.029) | 0.454 (0.027) | 5.021 (0.011) * | NS | p = 0.010 * | NS |
| MWI of NAWM (MWF) | 0.239 (0.005) | 0.221 (0.009) | 0.238 (0.008) | 4.639 (0.014) * | NS | p = 0.013 * | NS |
| Cervical cord MTCSF white:grey ratio of NAT/ mm3 | 0.847 (0.029) | 0.887 (0.052) | 0.833 (0.046) | 0.033 (0.01) * | NS | p = 0.023 * | p<0.001 * |
| Percentage change in brain volume over one year / mm3 | 0.068 (1.078) | -0.526 (1.135) | -0.222 (1.507) | 1.089 (0.38) | - | - | - |
| Change in average thalamic volume over one year / mm3 | 75.34 (143.1) | -136.24 (127.5) | 158.54 (238.4) | 9.272 (<0.01) * | NS | p = 0.007 * | p<0.001 * |
Abbreviations:
ANCOVA: analysis of co-variance
DTI: diffusion tensor imaging
MTSCF: Magnetisation transfer contrast normalized by CSF signal
MWI: myelin water imaging
NAT: Normal appearing tissue
NAWM: normal appearing white matter
NS: not significant
SD: standard deviation
*: significant difference (p<0.05).