Figure 1.
White matter regions of interest.
ICBM DTI-81 white matter atlas [33] depicted on FMRIB58 standard-space FA map [35]. Data-derived white matter skeleton mask in white. AnCr, anterior corona radiata; AnIC, anterior internal capsules; PoIC, posterior internal capsules; ReIC, retrolenticular internal capsules; EC, external capsules; FxCr, fornix crura; InCg, inferior cingula; SuCg, superior cingula; SLF, superior longitudinal fasciculi; FxCo, fornix columns; CCs, corpus callosum splenium; CCb, corpus callosum body; CCg, corpus callosum genu. Posterior corona radiata not depicted.
Table 1.
Fourteen white matter structures.
Table 2.
Patient characteristics.
Figure 2.
Significant changes in FA from pre-RT to end-RT.
Arrowheads: Z = −5, left inferior cingulum; Z = +25, corpus callosum body; Y = −40, left inferior cingulum; X = 0, fornix columns. Significant results per color chart, blue is TBSS skeleton without significant results. Depicted on Montreal Neurological Institute (MNI) ICBM152 standard brain T1-weighted image [34].
Figure 3.
Significant changes in RD from pre-RT to end-RT.
Arrowheads: Z = −5, left inferior cingulum; Z = +10, left fornix crus; Z = +25, corpus callosum body; Y = −40, left inferior cingulum; X = 0, fornix columns. Significant results per color chart, blue is TBSS skeleton without significant results. Depicted on MNI ICBM152 standard brain T1-weighted image [34]. Units are µm2/s.
Figure 4.
Significant changes in AD from pre-RT to one month post-RT.
Arrowheads: Z = +10, right superior longitudinal fasciculus; Z = +35, right superior cingulum; Y = −40, right superior cingulum. Significant results per color chart, blue is TBSS skeleton without significant results. Depicted on MNI ICBM152 standard brain T1-weighted image [34]. Units are µm2/s.
Figure 5.
Pre-RT to one month post-RT significant voxel overlap.
(a) Color key to significant voxel changes from pre-RT to one month post-RT in AD, RD, and FA with overlapping voxels. Underlying white matter skeleton with no significant changes is gray. (b) Venn diagram depicting proportion of white matter skeleton with significant changes. FA = 82.9%; RD = 37.4%; AD = 12.9%; FA ∩ RD = 33.5%; FA ∩ AD = 10.4%; RD ∩ AD = 0.1%. Labels are MNI coordinates.
Table 3.
Fractional anisotropy (FA) longitudinal changes by structure.
Table 4.
Radial diffusivity (RD) longitudinal changes by structure.
Table 5.
Axial diffusivity (AD) longitudinal changes by structure.
Table 6.
Repeated-measures ANOVA of FA changes from pre-RT to end-RT.
Figure 6.
Mean FA changes from pre-RT to end-RT in fourteen structures.
Comparisons by subject-paired two-sided t-test to Inferior Cingula (filled marker). *p<0.05; **p<0.00385 (Bonferroni correction). Error bars are 95% confidence interval.