Table II.
F statistics and P‐values for the main effects and interactions of “sequence” tested using repeated‐measures ANOVA
| Dependant variable | Explanatory model | F statistic (significance) | |
|---|---|---|---|
| Left optic radiation | Right optic radiation | ||
| λ|| | Sequence | 0.15 | 0.51 |
| Sequence × Group | 0.81 | 0.18 | |
| Sequence × Group × Segment | 0.89 | 1.17 | |
| λ⟂ | Sequence | 9.62 (P = 0.006) | 9.54 (P = 0.006) |
| Sequence × Group | 0.49 | 1.24 | |
| Sequence × Group × Segment | 0.5 | 1.18 | |
| MD | Sequence | 0.72 | 4.29 |
| Sequence × Group | 0.05 | 0.14 | |
| Sequence × Group × Segment | 0.6 | 1.22 | |
| FA | Sequence | 15.30 (P = 0.001) | 8.46 (P = 0.009) |
| Sequence × Group | 1.85 | 4.65 (P = 0.04) | |
| Sequence × Group × Segment | 0.65 | 0.83 | |
| α | Sequence | 0.02 | 0.02 |
| Sequence × Group | 0.7 | 0.03 | |
| Sequence × Group × Segment | 0.5 | 0.91 | |
These results confirm that despite the existence of a main effect for sequence for radial diffusivity and fractional anisotropy, no interaction terms were significant indicating that differences in DTI parameters attributable to DWI sequence did not affect group comparisons
Abbreviations: λ|| (axial diffusion coefficient), λ⟂ (radial diffusion coefficient), MD (mean diffusivity), FA (fractional anisotropy), α (angle of deviation of the principal eigenvector).