Volume 29, Issue 3
DOI: 10.24205/03276716.2020.738
Diffusion Tensor Imaging for the Development of Neonatal Brain Myelin
Abstract
Magnetic resonance diffusion tensor imaging (DTI) can be used to quantitatively determine fractional anisotropy (FA) values to reflect the white matter microstructure of the brain. In this study, we evaluate the application of DTI for the myelin development of cerebral white matter and compared different FA values in various brain regions for both term and preterm neonates. 100 healthy neonates with perinatal medical records were enrolled in this study. Newborns were divided into term (n = 39) and preterm group (n = 61) regarding to the gestational age (term > 37 weeks). Magnetic Resonance Imaging (MRI) and DTI scan were conducted to all infants to determine FA values in regions of interest (ROI), including bilateral white matter of cerebral hemisphere (WMCH), anterior limb of internal capsule (ALIC), posterior limb of internal capsule (PLIC), frontal periventricular zone (FPVZ), occipital periventricular zone (OPVZ), centrum semiovale (CS), subventricular zone (SVZ), corpus callosum genu/splenium (CCG & CCS), external capsule (EC) and middle cerebellar peduncles (MCP). The discrepancy of FA values in white matter regions between term and preterm neonates as well as their interior differences in various regions of newborns were analyzed. FA values in the same ROI between left and right hemisphere had no statistical difference (P> 0.05). The comparison of FA values between CCG and CCS in both preterm and term groups were statistical significant (P< 0.05). The FA values of preterm neonates in white matter regions were lower than that of terms. The comparison of FA values between preterm and term infants in ALIC, PLIC, CCS, CSb, EC and MCP was statistically significant (P< 0.05). The comparison of FA values between the two groups in CCG, FPVZ, OPVZ, CSa, SVZ had no significant difference (P>0.05). The interior FA values of preterm and term neonates in various WMCH were different. Paired comparison found that FA values in PLIC, OPVZ and CCS were higher than that in ALIC, FPVZ and CCG, respectively. All differences were statistically significant (P< 0.05). The comparison between CSa and CSb had no statistical significance (P> 0.05). The FA value was the lowest in FPVZ and highest in CCS and PLIC in all ROIs. The paired comparison of FA values in FPVZ vs. CCS or FPVZ vs. PLIC had a significant difference (P< 0.05). FA values of DTI can be used to quantitatively evaluate the maturity of myelin (brain white matter) development, which solves the problem of the subjective characterization and the absence of objective markers in traditional MRI. FA values also vary in different regions of the brain, reflecting the myelination time, white matter fiber arrangement and myelin selfstructure difference.
Keywords
neonates, diffusion tensor imaging, fractional anisotropy, myelination