Different patterns of cortical maturation before and after 38 weeks gestational age demonstrated by diffusion MRI in vivo
Year: 2018
Type: article
Study design: Observational Study
Abstract: Human cortical development during the third trimester is characterised by macro- and microstructural changes which are reflected in alterations in diffusion MRI (dMRI) measures, with significant decreases in cortical mean diffusivity (MD) and fractional anisotropy (FA). This has been interpreted as reflecting increased cellular density and dendritic arborisation. However, the fall in FA stops abruptly at 38 weeks post-menstrual age (PMA), and then tends to plateau, while MD continues to fall, suggesting a more complex picture and raising the hypothesis that after this age development is dominated by continuing increase in neural and organelle density rather than alterations in the geometry of dendritic trees. To test this, we used neurite orientation dispersion and density imaging (NODDI), acquiring multi-shell, high angular resolution dMRI and measures of cortical volume and mean curvature in 99 preterm infants scanned between 25 and 47 weeks PMA. We predicted that increased neurite and organelle density would be reflected in increases in neurite density index (NDI), while a relatively unchanging geometrical structure would be associated with constant orientation dispersion index (ODI). As dendritic arborisation is likely to be one of the drivers of gyrification, we also predicted that measures of cortical volume and curvature would correlate with ODI and show slower growth after 38 weeks. We observed a decrease of MD throughout the period, while cortical FA decreased from 25 to 38 weeks PMA and then increased. ODI increased up to 38 weeks and then plateaued, while NDI rose after 38 weeks. The evolution of ODI correlated with cortical volume and curvature. Regional analysis of cortical microstructure revealed a heterogenous pattern with increases in FA and NDI after 38 weeks confined to primary motor and sensory regions. These results support the interpretation that cortical development between 25 and 38 weeks PMA shows a predominant increase in dendritic arborisation and neurite growth, while between 38 and 47 weeks PMA it is dominated by increasing cellular and organelle density.
Source: NeuroImage
Language: English
Subfield: Radiology, Nuclear Medicine and Imaging
Field: Medicine
Domain: Health Sciences
Open Access status: hybrid
Estimated APC paid: $3,088
Funders: Wellcome Trust, King's College Hospital NHS Foundation Trust, National Institute for Health and Care Research, British Heart Foundation, Royal Society, King's College London, Medical Research Council, Engineering and Physical Sciences Research Council, Programme Grants for Applied Research, Centre For Medical Engineering, King’s College London, Niilo Helanderin Säätiö
Awards: G1054121244, The relation of cerebral oxygen delivery to brain dysmaturation and damage in infants with congenital heart disease, G1211483440, G1247657515, G1271318647, King's College London Medical Engineering Centre of Research Excellence, G2119833926, The Developing Brain, G2417159676, G339059223, G4859212381, In vivo microstructural neuroimaging in infants at risk of developing neurocognitive delay or neurobehavioural disorders, Imaging Focal Epilepsy in Children: A Developmental Perspective, G5296857752, G5728235598, G5797911231, G5893523844, King's College London Medical Engineering Centre of Research Excellence, G5935007269, Evaluation of MR imaging to predict neurodevelopmental impairment in preterm infants, G7587803570, Imaging Focal Epilepsy in Children: A Developmental Perspective, G7804309329, G8101219992, G8131728046, G8208673703, G8303168876, G841698483, G8775246936, G9000139232, G938335843, G961285871
OpenAlex ID: W2804580576