Table 4:
Twin ACE modeling of diffusion tensor imaging (DTI) measures of AD, RD and MD in specific Johns Hopkins University template white matter regions. N=438
| AD | RD | MD | |||||||
|---|---|---|---|---|---|---|---|---|---|
| a2 | c2 | e2 | a2 | c2 | e2 | a2 | c2 | e2 | |
| Projection fibers: | |||||||||
| Anterior corona radiata-L | 0.73 | 0.00 | 0.27 | 0.81 | 0.00 | 0.19 | 0.82 | 0.00 | 0.18 |
| Anterior corona radiata-R | 0.74 | 0.00 | 0.26 | 0.83 | 0.00 | 0.17 | 0.87 | 0.00 | 0.13 |
| Superior corona radiata-L | 0.67 | 0.00 | 0.33 | 0.80 | 0.00 | 0.20 | 0.82 | 0.00 | 0.18 |
| Superior corona radiata-R | 0.82 | 0.00 | 0.18 | 0.83 | 0.00 | 0.17 | 0.85 | 0.00 | 0.15 |
| Posterior corona radiata-L | 0.52 | 0.28 | 0.20 | 0.81 | 0.00 | 0.19 | 0.72 | 0.14 | 0.14 |
| Posterior corona radiata-R | 0.40 | 0.43 | 0.17 | 0.83 | 0.00 | 0.17 | 0.88 | 0.00 | 0.12 |
| Anterior limb of internal capsule-L | 0.64 | 0.01 | 0.35 | 0.71 | 0.00 | 0.29 | 0.62 | 0.00 | 0.38 |
| Anterior limb of internal capsule-R | 0.62 | 0.00 | 0.38 | 0.70 | 0.00 | 0.30 | 0.66 | 0.00 | 0.34 |
| Posterior limb of internal capsule-L | 0.71 | 0.00 | 0.29 | 0.40 | 0.28 | 0.32 | 0.24 | 0.38 | 0.38 |
| Posterior limb of internal capsule-R | 0.55 | 0.07 | 0.38 | 0.70 | 0.00 | 0.30 | 0.56 | 0.00 | 0.44 |
| Posterior thalamic radiation-L | 0.32 | 0.39 | 0.29 | 0.71 | 0.05 | 0.23 | 0.43 | 0.35 | 0.22 |
| Posterior thalamic radiation-R | 0.41 | 0.36 | 0.23 | 0.75 | 0.00 | 0.25 | 0.71 | 0.08 | 0.21 |
| Association fibers: | |||||||||
| Superior longitudinal fasciculus-L | 0.47 | 0.28 | 0.25 | 0.87 | 0.00 | 0.13 | 0.85 | 0.02 | 0.13 |
| Superior longitudinal fasciculus-R | 0.56 | 0.20 | 0.24 | 0.86 | 0.00 | 0.14 | 0.87 | 0.00 | 0.13 |
| Superior fronto-occipital fasciculus-L | 0.40 | 0.00 | 0.60 | 0.54 | 0.00 | 0.46 | 0.62 | 0.00 | 0.38 |
| Superior fronto-occipital fasciculus-R | 0.42 | 0.00 | 0.58 | 0.62 | 0.00 | 0.38 | 0.62 | 0.00 | 0.38 |
| Cingulum-L | 0.51 | 0.08 | 0.41 | 0.73 | 0.00 | 0.27 | 0.73 | 0.01 | 0.26 |
| Cingulum-L | 0.66 | 0.00 | 0.34 | 0.76 | 0.00 | 0.24 | 0.78 | 0.00 | 0.22 |
| Uncinate fasciculus-L | 0.48 | 0.00 | 0.52 | 0.48 | 0.00 | 0.52 | 0.11 | 0.21 | 0.68 |
| Uncinate fasciculus-R | 0.22 | 0.23 | 0.55 | 0.39 | 0.00 | 0.61 | 0.39 | 0.05 | 0.56 |
| Sagittal Stratum-L | 0.53 | 0.13 | 0.34 | 0.73 | 0.00 | 0.27 | 0.78 | 0.00 | 0.22 |
| Sagittal Stratum-R | 0.33 | 0.30 | 0.37 | 0.75 | 0.00 | 0.25 | 0.61 | 0.14 | 0.25 |
| Commissural fibers: | |||||||||
| Genu of corpus callosum | 0.71 | 0 | 0.29 | 0.81 | 0 | 0.19 | 0.82 | 0 | 0.18 |
| Body of corpus callosum | 0.60 | 0 | 0.40 | 0.72 | 0 | 0.28 | 0.74 | 0 | 0.26 |
| Splenium of corpus callosum | 0.45 | 0.26 | 0.29 | 0.67 | 0 | 0.33 | 0.68 | 0 | 0.32 |
| Tracts in the brainstem: | |||||||||
| Corticospinal tracts-L | 0.56 | 0.00 | 0.44 | 0.65 | 0.00 | 0.35 | 0.60 | 0.00 | 0.40 |
| Corticospinal tracts-R | 0.37 | 0.01 | 0.62 | 0.59 | 0.00 | 0.41 | 0.51 | 0.00 | 0.49 |
| Cerebral peduncle-L | 0.29 | 0.16 | 0.55 | 0.54 | 0.00 | 0.46 | 0.13 | 0.13 | 0.74 |
| Cerebral peduncle-R | 0.44 | 0.04 | 0.52 | 0.37 | 0.03 | 0.60 | 0.30 | 0.09 | 0.61 |
| Middle cerebellar peduncle | 0.60 | 0.00 | 0.40 | 0.71 | 0 | 0.29 | 0.63 | 0.00 | 0.37 |
| Global Measure: | 0.65 | 0.15 | 0.20 | 0.73 | 0.00 | 0.27 | 0.67 | 0.00 | 0.33 |
Note: Full ACE model fit is shown. Estimates of zero for c2 were empirically driven to their boundary at zero in these ACE models.