Population means and 99% normal ranges (in parentheses) of MR parameter interquartile ranges across our population of healthy individuals. Data obtained at 3T.
| Reconstruction Type | T1 (ms) | T2 (ms) | MTR | FA | MD (×104 mm2/s) | λ1 (×104 mm2/s) | λ2 (×104 mm2/s) | λ3 (×104 mm2/s) | λ⊥ (×104 mm2/s) |
|---|---|---|---|---|---|---|---|---|---|
| No. of individuals | 11 | 17 | 15 | 20 | 20 | 20 | 20 | 20 | 20 |
| Whole brain | 340 (150, 530) | 14 (0.20, 27) | 0.044 (0.010, 0.078) | 0.24 (0.17, 0.30) | 1.4 (0.79, 2.0) | 4.3 (3.1, 5.6) | 2.1 (1.4, 2.8) | 2.2 (1.5, 3.0) | 2.0 (1.3, 2.6) |
| Hemispheres | 320 (170, 460) | 9.8 (4.6, 15) | 0.037 (0.0013, 0.072) | 0.23 (0.14, 0.32) | 0.96 (0.47, 1.4) | 3.9 (2.3, 5.5) | 1.7 (1.1, 2.3) | 1.9 (1.2, 2.5) | 1.6 (0.99, 2.3) |
| Brain stem | 170 (82, 260) | 21 (−15, 57) | 0.039 (0.017, 0.062) | 0.18 (0.12, 0.25) | 2.4 (0.60, 4.2) | 3.9 (1.6, 6.2) | 2.8 (1.4, 4.2) | 2.8 (0.96, 4.6) | 2.5 (1.0, 4.0) |
Note:—MTR indicates magnetization transfer ratio; FA, fractional anisotropy; MD, mean diffusivity; λ⊥, transverse diffusivity (average of λ2 and λ3).