Table 2.
Mean and Standard Deviation (in parentheses) for Right and Left Superior Longitudinal Fasciculus Metrics and Asymmetry Indices.
| Metric | Right Superior Longitudinal Fasciculus | Left Superior Longitudinal Fasciculus | Asymmetry Index | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Controls (N=23) |
Patients (N=27) |
p-value | Controls (N=23) |
Patients (N=27) |
p-value | Controls (N=23) |
Patients (N=27) |
p-value | |
| Number of Crossing Fibers | 1.87 (0.09) | 1.87 (0.15) | NS | 1.82 (0.10) | 1.90 (0.14) | .04 | 1.19 (2.36) | −.64 (2.30) | .008 |
| MDA | .476 (0.02) | .475 (0.01) | NS | .490 (0.02) | .479 (0.01) | 01 | −1.43 (1.64) | −.34 (1.54) | .019 |
| GFA | .179 (.007) | .180 (.006) | NS | .185 (.008) | .179 (.006) | .006 | −1.51 (1.84) | .08 (1.94) | .005 |
| FA | .463 (0.03) | .462 (0.02) | NS | .472 (0.03) | .453 (0.02) | .004 | −1.05 (2.15) | .96 (2.17) | .002 |
| Volume (cc) | 12.7 (4.5) | 11.4 (3.0) | NS | 12.3 (3.9) | 11.9 (2.9) | NS | 1.20 (10.2) | −2.28 (11.1) | NS |
Notes. Number of crossing fibers = number of ODF peaks found for each voxel; MDA (multi directional anisotropy) = anisotropy calculated from ODFs by using ratio of peaks to troughs in the ODFs and identical to FA for single-directional Gaussian diffusion with values ranging from 0 to 1; GFA (generalized fractional anisotropy) defined according to Tuch (2004); and FA (fractional anisotropy) = anisotropy calculated based on a DTI model with values ranging from 0 to 1; Volume = volume based on traversed locations for tract. The asymmetry index was computed using the following formula = [(R−L)/(R+L)] * 100.