Article Figures & Data
Figures
- Fig 1.
Axial MR images illustrated changes on T1-, PD-, and T2-weighted images with increasing age. Right sides of the images represent the right side of the body. Note the inverted T2-weighted contrast at 18 months in the child with 18q− and low T2- and PD-weighted contrast extending to 124 months.
A, Three healthy control children.
B, Three children with 18q−.
- Fig 2.
Myelin (fmy), myelinated axon (fma), and mixed (fmx) pool fractions in typically developing children (normal) and in children with 18q− as a function of age and the regions in A–F.
A, FWM.
B, SWM.
C, PWM.
D, Genu of the CC.
E, Splenium of the CC.
F, MCBP.
Tables
Region Onset (months) TC (months) Maturation Age (months) 18q− Control 18q− Control 18q− Control FWM 6.7 ± 0.54 1.8 ± 1.03 16.3 ± 2.54 10.3 ± 0.30 71.9 ± 10.17 43.2 ± 1.59 SWM 3.6 ± 0.94 0.8 ± 0.16 12.4 ± 0.95 6.3 ± 0.75 53.2 ± 3.93 26.0 ± 3.02 PWM 3.7 ± 1.75 1.9 ± 0.25 12.7 ± 3.59 8.2 ± 0.93 54.5 ± 14.40 34.7 ± 3.74 Genu 2.6 ± 1.10 1.9 ± 0.51 13.1 ± 0.57 5.4 ± 0.27 55.0 ± 2.54 23.5 ± 1.18 Splenium 3.1 ± 0.45 2.3 ± 0.11 8.1 ± 2.44 2.4 ± 0.47 35.5 ± 9.77 11.9 ± 1.90 MCBP −4.9 ± 0.49 −3.9 ± 0.60 12.1 ± 2.87 4.1 ± 0.47 43.5 ± 11.50 12.5 ± 1.97 Note.—TC is the time constant for myelination model; maturation age, Age when myelin development reaches about 98% of the equilibrium level (onset + 4TC). All SDs estimated by using propagation of errors from Bevington et al (24).
Region fmy fma fmx fmy/fma 18q− Control 18q− Control 18q− Control 18q− Control FWM 0.067 ± 0.023 0.171 ± 0.021 0.458 ± 0.035 0.536 ± 0.027 0.474 ± 0.036 0.295 ± 0.018 0.147 0.319 SWM 0.085 ± 0.017 0.183 ± 0.021 0.423 ± 0.022 0.475 ± 0.028 0.493 ± 0.027 0.343 ± 0.021 0.200 0.387 PWM 0.079 ± 0.023 0.186 ± 0.012 0.394 ± 0.059 0.463 ± 0.026 0.526 ± 0.045 0.351 ± 0.022 0.200 0.403 Genu 0.034 ± 0.020 0.155 ± 0.020 0.542 ± 0.025 0.602 ± 0.031 0.423 ± 0.026 0.245 ± 0.026 0.063 0.257 Splenium 0.053 ± 0.015 0.157 ± 0.022 0.515 ± 0.075 0.538 ± 0.052 0.444 ± 0.071 0.304 ± 0.038 0.102 0.292 MCBP 0.043 ± 0.025 0.117 ± 0.022 0.469 ± 0.054 0.461 ± 0.041 0.489 ± 0.047 0.421 ± 0.028 0.091 0.254 Note.—fmy indicates the myelin pool fraction; fma, myelinated axon pool fraction; and fmx, mixed pool fraction. Equilibrium fractions are from the model ± SDs of measured fractions about these values for age >4 years.
