Tract | FA | MD (×10−3 mm2/s) | λ// (×10−3 mm2/s) | λ⊥ (×10−3 mm2/s) | Volume (cm3) |
---|---|---|---|---|---|
Genu of the corpus callosum | 0.012 | 0.017 | 0.023 | 0.016 | 1.15 |
Body of the corpus callosum | 0.013 | 0.022 | 0.034 | 0.020 | 2.29 |
Splenium of the corpus callosum | 0.012 | 0.024 | 0.032 | 0.022 | 1.06 |
Corticospinal tract | 0.019 | 0.025 | 0.030 | 0.025 | 1.23 |
Cingulum | 0.016 | 0.012 | 0.020 | 0.017 | 0.54 |
Inferior longitudinal fasciculus | 0.007 | 0.012 | 0.017 | 0.012 | 1.27 |
Inferior fronto-occipital fasciculus | 0.012 | 0.012 | 0.022 | 0.011 | 2.65 |
Superior longitudinal fasciculus | 0.009 | 0.010 | 0.012 | 0.012 | 1.25 |
Superior fronto-occipital fasciculus | 0.009 | 0.011 | 0.013 | 0.012 | 0.72 |
Uncinate fasciculus | 0.010 | 0.012 | 0.025 | 0.022 | 0.83 |
Seven subjects were scanned three to four times each within 6 months to determine reliability of the diffusion and tract volume measurements over time. The mean of the SDs over all scans per subject are shown for each parameter [FA, MD, parallel (λ//) and perpendicular diffusivity (λ⊥), and tract volume], which were then used as a threshold for determining whether the parameters increased or decreased between scans in the study population.