Detailed semiautomated MRI based morphometry of the neonatal brain: Preliminary results

Abstract

In the neonate, regional growth trajectories provide information about the coordinated development of cerebral substructures and help identify regional vulnerability by identifying times of faster growth. Segmentation of magnetic resonance images (MRI) has provided detailed information for the myelinated brain but few reports of regional neonatal brain growth exist. We report the method and preliminary results of detailed semiautomated segmentation of 12 normative neonatal brains (gestational age 31.1 -42.6 weeks at time of MRI) using volumetric T1-weighted images. Accuracy was confirmed by expert review of every segmented image. In 5 brains, repeat segmentation resulted in intraclass correlation coefficients >0.9 (except for the right amygdala) and an average percent voxel overlap of 90.0%. Artifacts or image quality limited the number of regions segmented in 9/12 data sets and 1/12 was excluded from volumetric analysis due to ventriculomegaly. Brains were segmented into cerebral exterior (N = Linear growth ( P < 0.05) was identified in all regions except the cerebral white matter, medulla and ventricles. Striking differences in regional growth rates were noted. These preliminary results are consistent with the heterochronous nature of cerebral development and provide initial estimates of regional brain growth and therefore regional vulnerability in the perinatal time period. D8

Regional Gray Matter Growth, Sexual Dimorphism, and Cerebral Asymmetry in the Neonatal Brain

“…Although there has been a great deal of recent interest in the study of childhood and adolescent brain development, very little is known about normal brain development in the first few months of life. Previous magnetic resonance imaging (MRI) studies of a small number of healthy neonates being compared with prematurely born infants found gray and white matter volumes increased in the perinatal period (Huppi et al, 1998;Peterson et al, 2003); in a recent preliminary study, white matter growth appeared to slow after the 36 week gestational age (Nishida et al, 2006).…”

Regional and Hemispheric Asymmetries of Cerebral Hemodynamic and Oxygen Metabolism in Newborns

“…Studies of brain development in large populations of neonates have not been performed because volumetric analysis of newborn brain MRIs is time intensive if small structures or regional segmentations are needed (Nishida et al 2006). PET and single-photon emission computed tomography (SPECT) can be performed only on sick infants when clinically necessary, due to the radiation exposure required for these techniques.…”

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

“…Because automated and semi-automated MR imaging segmentation techniques were developed for volumetric T1 studies of the fully myelinated mature brain and are not directly transferable to the incompletely myelinated brain, 26 no segmentation procedure to separate gray and white matter was performed. 18,20 Images were spatially normalized in SPM2 with a reference template that consisted of the b ϭ 0 s/mm 2 image of 1 healthy term subject who had no motion artifacts.…”