PT  - JOURNAL ARTICLE
AU  - Ho, Chang Y.
AU  - Persohn, Scott
AU  - Sankar, Meghana
AU  - Territo, Paul R.
TI  - Development of Myelin Growth Charts of the White Matter Using T1 Relaxometry
AID  - 10.3174/ajnr.A8306
DP  - 2024 Sep 01
TA  - American Journal of Neuroradiology
PG  - 1335--1345
VI  - 45
IP  - 9
4099  - http://www.ajnr.org/content/45/9/1335.short
4100  - http://www.ajnr.org/content/45/9/1335.full
SO  - Am. J. Neuroradiol.2024 Sep 01; 45
AB  - BACKGROUND AND PURPOSE: Myelin maturation occurs in late fetal life to early adulthood, with the most rapid changes observed in the first few years of infancy. To quantify the degree of myelination, a specific MR imaging sequence is required to measure the changes in tissue proton relaxivity (R1). R1 positively correlates with the degree of myelination maturation at a given age. Similar to head circumference charts, these data can be used to develop normal growth charts for specific white matter tracts to detect pathologies involving abnormal myelination.MATERIALS AND METHODS: This is a cross-sectional study using normal clinical pediatric brain MR images with the MP2RAGE sequence to generate T1 maps. The T1 maps were segmented to 75 brain regions from a brain atlas (white matter and gyri). Statistical modeling for all subjects across regions and the age range was computed, and estimates of population-level percentile ranking were computed to describe the effective myelination rate as a function of age. Test-retest analysis was performed to assess reproducibility. Logistic trendline and regression were performed for selected white matter regions and plotted for growth charts.RESULTS: After exclusion for abnormal MR imaging or diseases affecting myelination from the electronic medical record, 103 subject MR images were included, ranging from birth to 17 years of age. Test-retest analysis resulted in a high correlation for white matter (r = 0.88) and gyri (r = 0.95). All white matter regions from the atlas had significant P values for logistic regression with R2 values ranging from 0.41 to 0.99.CONCLUSIONS: These data can serve as a myelination growth chart to permit patient comparisons with normal levels with respect to age and brain regions, thus improving detection of developmental disorders affecting myelin.R1tissue proton relaxivity