Background and aim Our aim was to analyse the development of cortical morphology in preterm infants, as alterations in cortical folding affect functional development.
Methods MRI was performed at 30 and 40 weeks corrected age in 19 preterm born infants (gestational age (GA) 24.71–27.86 wks, 11 males). After automatic brain tissue segmentation,1 a 3D reconstruction of the inner cortical surface was computed and cortical sulci were labelled with Brainvisa software.2 We measured global sulcal index (SI=folded/unfolded surface areas), and per sulcus surface area (SA, mm2) and mean geodesic depth (MGD, mm), all corrected for scan-age.
Results In 10 weeks, SI increased from 0.18 to 1.08 (6 times, 40 wks: right > left). Central sulcus, lateral fissure, and insula increased more in SA (resp. 2.3, 2.6, 1.7-times) than in MGD (resp.1.2, 1.1, 1.3-times). The superior temporal sulcus (STS) expanded in SA with factor 16.3 left and 12.6 right (30 wks: right > left), and factor 1.6 in MGD (30 and 40 wks: right > left). White matter injury in these infants (9 IVH,1 PVHI, 4 treated for PHVD) or GA did not significantly influence cortical morphology changes.
Conclusion Over this short period, cortical folding is immense in preterm newborns, and shows inter-hemispherical asymmetries. Sulci increased more in surface area than in depth, STS showed the largest increase. The influence of brain injury on cortical morphology needs to be elucidated in a larger cohort.
Chita S, et al. Medical Imaging (2013)
Perrot M, et al. Medical Image Analysis (2011)