Table 1.

Tractography-derived SDs over multiple scans

TractFAMD (×10−3 mm2/s)λ// (×10−3 mm2/s)λ (×10−3 mm2/s)Volume (cm3)
Genu of the corpus callosum0.0120.0170.0230.0161.15
Body of the corpus callosum0.0130.0220.0340.0202.29
Splenium of the corpus callosum0.0120.0240.0320.0221.06
Corticospinal tract0.0190.0250.0300.0251.23
Cingulum0.0160.0120.0200.0170.54
Inferior longitudinal fasciculus0.0070.0120.0170.0121.27
Inferior fronto-occipital fasciculus0.0120.0120.0220.0112.65
Superior longitudinal fasciculus0.0090.0100.0120.0121.25
Superior fronto-occipital fasciculus0.0090.0110.0130.0120.72
Uncinate fasciculus0.0100.0120.0250.0220.83
  • 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.