Anatomic Location | FA | MK | ||||||
---|---|---|---|---|---|---|---|---|
R2a | % Δ (Birth to 2 yr)b | % Δ (Birth to 4 yr 7 mo)c | 90% of FAmax (mo)d | R2a | % Δ (Birth to 2 yr)b | % Δ (Birth to 4 yr 7 mo)c | 90% of MKmax (mo)d | |
Splenium | 0.66 | 70 | 71 | 9 | 0.82 | 157 | 165 | 15 |
Genu | 0.63 | 81 | 89 | 16 | 0.85 | 115 | 129 | 19 |
Frontal WM | 0.69 | 172 | 173 | 8 | 0.92 | 233 | 265 | 23 |
Parietal WM | 0.77 | 111 | 116 | 13 | 0.94 | 236 | 257 | 19 |
Anterior IC | 0.62 | 103 | 103 | 6 | 0.85 | 182 | 184 | 10 |
Posterior IC | 0.61 | 48 | 48 | 4 | 0.84 | 158 | 159 | 9 |
EC | 0.59 | 63 | 63 | 5 | 0.87 | 160 | 174 | 18 |
Thalamus | 0.45 | 63 | 66 | 10 | 0.78 | 136 | 137 | 8 |
Putamen | 0.03 | −7 | −18 | N/A | 0.68 | 80 | 81 | 8 |
Note:—NA indicates not applicable; EC external capsule.
a Coefficient of determination (R2) demonstrating the goodness of exponential fit for the FA and MK nonlinear monoexponential regression curves.
↵b Percentage change in FA and MK absolute values from birth to 2 years of age.
↵c Percentage change in FA and MK absolute values from birth to 4 years 7 months of age.
↵d Approximate age in months at which 90% of developmental plateau is reached since birth for both FA and MK datasets (ie, FAmax and MKmax).