Are Developmental Trajectories of Cortical Folding Comparable Between Cross-sectional Datasets of Fetuses and Preterm Newborns?

Abstract

Magnetic resonance imaging has proved to be suitable and efficient for in vivo investigation of the early process of brain gyrification in fetuses and preterm newborns but the question remains as to whether cortical-related measurements derived from both cases are comparable or not. Indeed, the developmental folding trajectories drawn up from both populations have not been compared so far, neither from cross-sectional nor from longitudinal datasets. The present study aimed to compare features of cortical folding between healthy fetuses and early imaged preterm newborns on a cross-sectional basis, over a developmental period critical for the folding process (21-36 weeks of gestational age [GA]). A particular attention was carried out to reduce the methodological biases between the 2 populations. To provide an accurate group comparison, several global parameters characterizing the cortical morphometry were derived. In both groups, those metrics provided good proxies for the dramatic brain growth and cortical folding over this developmental period. Except for the cortical volume and the rate of sulci appearance, they depicted different trajectories in both groups suggesting that the transition from into ex utero has a visible impact on cortical morphology that is at least dependent on the GA at birth in preterm newborns.

Mimicking Cortex Convolutions Through the Wrinkling of Growing Soft Bilayers

“…In Fig. (8), a comparison with measurements made with MRI [38], close to the gyri initiation, is performed, G I being smaller than 1.6 while the brain mass is smaller than 200mL. The two data sets (blue and red points) correspond respectively to pre-term babies and fetuses after a similar period of gestation, for comparison.…”

“…Our understanding of the growth dynamics of the brain in fetal life will increase in the next future as the same time as its connection with pathologies [25,38]. However, the simple buckling of a double elastic layer of soft tissues is itself rather poorly understood and many works accept wavelength relationships out of their domain of application.…”

“…To find the k number, we expand the solvability condition Eq. (38) in the vicinity of the root of D a , given by Eq. (27), and define the key parameter R 1 : where D a is the derivative of D a with respect toJ 1 = J c .…”

Exploring the successive waves of cortical folding in the developing brain using MRI and spectral analysis of gyrification

“…The scaling exponent of the model was compared to the theoretical one under the hypothesis of strictly proportional geometric dependence between surface and volume, to demonstrate non proportional scaling called allometry [7]. Variations in SPANGY parameters with age were further studied in order to identify developmental periods showing specific features of folding or discontinuities.…”

“…Understanding their complexity requires to map the folding process in vivo from the early stages, which has become possible in the recent years with non-invasive magnetic resonance imaging (MRI) combined with post-processing tools to extract cortical surfaces [5]. In cross-sectional populations of fetuses and pre-term newborns, folding features have been measured, showing dramatic increase with age [6,7]. Nevertheless there is still no quantitative way to disentangle between primary, secondary and tertiary folds in a single newborn brain.…”