TY - JOUR
T1 - Myelination in children with partial deletions of chromosome 18q
AU - Lancaster, Jack L.
AU - Cody, Jannine D.
AU - Andrews, Trevor
AU - Hardies, L. Jean
AU - Hale, Daniel E.
AU - Fox, Peter T.
PY - 2005
Y1 - 2005
N2 - BACKGROUND AND PURPOSE: We compared myelin levels in white matter (WM) in typically developing children with those of children with partial deletions of chromosome 18q (18q-). METHODS: Conventional spin-echo MR imaging at 1.9T was used to acquire T1-, T2-, and proton density-weighted images of the brain. From these images, a three-pool model was used to estimate the fraction of water in myelin, myelinated axon, and mixed water compartments (or pools) in six WM regions. A model curve was fit to the pool fractions to model the trend of myelin development by age in each region. Water-pool fractions in children with 18q- aged 5 months to 13 years were compared with those of age-matched, typically developing children. RESULTS: In children with 18q-, the model predicted later onset of myelination (P < .02), lower myelination rates (P < .001), and smaller equilibrium myelin pool fractions (P < .001). Significant differences were seen between the two groups for all three water pool fractions (P < .001). The mixed pool fraction was larger in children with 18q-. Although the myelin pool fraction was significantly smaller, the myelinated axon pool fraction was only slightly smaller, leading to a significantly smaller estimate of myelin per myelinated axon in children with 18q-(P < .001). CONCLUSION: Myelination modeling in 18q- children indicated delayed onset, a lower rate of myelination, and equilibrium myelin levels less than 50% those of age-matched, typically developing children.
AB - BACKGROUND AND PURPOSE: We compared myelin levels in white matter (WM) in typically developing children with those of children with partial deletions of chromosome 18q (18q-). METHODS: Conventional spin-echo MR imaging at 1.9T was used to acquire T1-, T2-, and proton density-weighted images of the brain. From these images, a three-pool model was used to estimate the fraction of water in myelin, myelinated axon, and mixed water compartments (or pools) in six WM regions. A model curve was fit to the pool fractions to model the trend of myelin development by age in each region. Water-pool fractions in children with 18q- aged 5 months to 13 years were compared with those of age-matched, typically developing children. RESULTS: In children with 18q-, the model predicted later onset of myelination (P < .02), lower myelination rates (P < .001), and smaller equilibrium myelin pool fractions (P < .001). Significant differences were seen between the two groups for all three water pool fractions (P < .001). The mixed pool fraction was larger in children with 18q-. Although the myelin pool fraction was significantly smaller, the myelinated axon pool fraction was only slightly smaller, leading to a significantly smaller estimate of myelin per myelinated axon in children with 18q-(P < .001). CONCLUSION: Myelination modeling in 18q- children indicated delayed onset, a lower rate of myelination, and equilibrium myelin levels less than 50% those of age-matched, typically developing children.
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M3 - Article
C2 - 15760848
AN - SCOPUS:16844368082
SN - 0195-6108
VL - 26
SP - 447
EP - 454
JO - American Journal of Neuroradiology
JF - American Journal of Neuroradiology
IS - 3
ER -