Maturation of Thalamic Radiations between 34 and 41 Weeks' Gestation: A Combined Voxel-Based Study and Probabilistic Tractography with Diffusion Tensor Imaging

Abstract

BACKGROUND AND PURPOSE:This study aimed to investigate brain maturation along gestational age with diffusion tensor imaging in healthy preterm and term neonates. Therefore, a voxel-based study of fractional anisotropy (FA) and mean diffusivity (D av ) was performed to reveal the brain regions experiencing microstructural changes with age. With tractography, the authors intended to identify which fiber tracts were included in these significant voxels.

Gender Differences in Language and Motor-Related Fibers in a Population of Healthy Preterm Neonates at Term-Equivalent Age: A Diffusion Tensor and Probabilistic Tractography Study

“…[72][73][74] Another hypothesis is that our results may have been influenced by the effect of prematurity. Indeed, even if the normality of our preterm population was based on robust structural and clinical criteria, as in previous studies, 48,52 we cannot exclude the possibility that the sex related differences observed in the language and motor networks may have been caused by subtle cerebral lesions, because certain studies seem to suggest that preterm males may be more sensitive to brain injuries than females. 75,76 Therefore, it would be of interest to investigate whether these sex differences are also present in healthy term neonates.…”

“…51 Finally, the obtained connectivity distributions were thresholded with a probability of 2%. 48,52,53 We calculated the TBV by measuring the volume of the voxels located in the brain mask. 14,54 To assess tract macrostructure, tract volumes and relative tract volumes (defined as the ratio between individual tract volume and TBV) were computed.…”

Tractography of the corticospinal tracts in infants with focal perinatal injury: comparison with normal controls and to motor development

“…To our knowledge, there have been no studies assessing the CSTs in infants with focal lesions using tractography in the neonatal period. Furthermore, there have been few tractography studies assessing the healthy infant brain [16,17].…”

Comparison of Spin-Echo T1- and T2-Weighted and Gradient-Echo T1-Weighted Images at 3T in Evaluating Very Preterm Neonates at Term-Equivalent Age

“…An imaging data base and clinical record review during 3 years (January 2007-January 2010) yielded 24 very preterm infants (Ͻ30 weeks) who underwent 3T MR imaging at term-equivalent age (38 -42 weeks) that used all 3 sequences, SE-T1WI, GRE-T1WI, and SE-T2WI, and had no neurologic symptoms at clinical follow-up at 9 months of age or older (as determined by a pediatric neurologist), based on inclusion criteria from a previous study with a similar patient population. 7 Of the 24 patients from the data base search, 13 were excluded at initial review: 9 due to MR imaging abnormalities such as hypoxic-ischemic insult or T1-bright periventricular foci (n ϭ 4), germinal matrix or paren-chymal hemorrhage (n ϭ 3), periventricular leukomalacia (n ϭ 1), or a congenital structural abnormality (n ϭ 1). The remainder of excluded patients were due to suboptimal imaging or severe motion (n ϭ 4).…”