Table 3:

99% normal ranges of absolute asymmetry indices for fiber number, tract volume, and summary statistics of MR parameters across our population of healthy volunteers

Reconstruction Type	No. of fibers	Vol.	T1	T2	MTR	FA	MD	λ₁	λ₂	λ₃	λ_⊥
No. of individuals	20	20	11	17	15	20	20	20	20	20	20
Whole brain	1.0	0.64	0.053 (0.20)	0.035 (0.21)	0.012 (0.20)	0.051 (0.16)	0.028 (0.28)	0.041 (0.16)	0.052 (0.21)	0.092 (0.20)	0.064 (0.19)
Hemispheres	0.56	0.31	0.047 (0.13)	0.026 (0.17)	0.015 (0.23)	0.068 (0.20)	0.023 (0.19)	0.033 (0.20)	0.059 (0.19)	0.098 (0.18)	0.071 (0.20)
Brain stem	0.97	0.54	0.054 (0.31)	0.087 (0.34)	0.021 (0.29)	0.073 (0.15)	0.10 (0.31)	0.097 (0.28)	0.12 (0.20)	0.18 (0.26)	0.13 (0.22)

Note:—MTR indicates magnetization transfer ratio; FA, fractional anisotropy; MD, mean diffusivity; λ_⊥, transverse diffusivity (average of λ₂ and λ₃). For the MR parameters, cutoffs for medians and interquartile ranges (in parentheses) are given. Data obtained at 3T.