Magnetic resonance imaging of normal and pathological white matter maturation

Abstract

Fifty children between 3 months postnatal and 16 years of age were examined by means of a 1.5 T superconductive magnet, run at 0.35 and 1.0 T. The myelination was studied qualitatively and quantitatively (relaxation times, proton densities, image contrast). With increasing age, a decrease of T1 and proton density of white matter was found, which was complete at one year of age. In regions with a slow progression of myelination, gray/white matter contrast showed an increase up to the end of the first decade. Pathological white matter maturation was diagnosed either as an abnormal transformation of myelin (characterized by abnormal relaxation values), or as a deficient or delayed myelin formation (in comparison with age-matched controls).

A quantitative measure of myelination development in infants, using MR images

“…It is wellknown that the developmental changes in water content of the brain affect the MR signal and that most water content of the brain reduces in the first year [12,21]. The T1 values decrease steadily during the first year for white and gray matter, with no changes after age 1 year [26]. Histologic studies of the brains of infants less than 12 months of age found that the increase in white matter intensity on T1-weighted images is explained by water decrease in the brain, not by myelination [15].…”

Myelination progression in language-correlated regions in brain of normal children determined by quantitative MRI assessment

“…In previous studies, myelination was examined by using MRI qualitative or semiquantitative ratings in normal infants and children [8,15,16,18,20,22,[27][28][29][30]36,38,39]. As many studies have shown that delayed myelination in children is related to developmental delay [13,14,16,31,40], it is important to establish the pace of myelination in normal children.…”

“…As many studies have shown that delayed myelination in children is related to developmental delay [13,14,16,31,40], it is important to establish the pace of myelination in normal children.…”

“…Myelin is hydrophobic, and myelin formation is associated with a decrease in water content, which can be detected by MRI. The use of MRI to evaluate myelination visually and quantitative assessment of myelination-associated changes in the signal intensity of regions of interest (ROI) in the brain for detecting subtler changes has been reported [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29]. However, a time lag has been noted between the determination of myelination by histological staining and its determination by MRI [7,15,21,[29][30][31].…”

Advanced Magnetic Resonance Imaging Techniques in Perinatal Brain Injury¹

“…The significance of finding abnormalities in myelination in relation to functional (neuro)development has been studied extensively. Correlation was found between neurodevelopmental delay and delay in myelination [53][54][55][56][57][58][59][60][61].…”