Presented at the Neonatal Society 2018 Spring Meeting.
Kimpton JA, Batalle D, Barnett M, Hughes E, Chew A, Falconer S, Tournier JD, Edwards AD, Counsell SJ
Centre for the Developing Brain, King’s College London, St Thomas’ Hospital, London, UK
Background: Diffusion magnetic resonance imaging (dMRI) studies report altered white matter (WM) development in preterm infants, which correspond to impaired neurodevelopmental outcomes. New dMRI methods such as neurite orientation dispersion and density imaging (NODDI) provide realistic estimations of neurite architecture in vivo (1). We studied a population of neonates from 25-45 weeks gestation with normal developmental outcome scores and hypothesised that WM maturation corresponds more closely to NODDI than traditional dMRI metrics.
Methods: 33 neonates (n=19 male) with median (range) age at birth of 32+4 (24+2-38+0) weeks had a 3-T MRI brain scan at median (range) post menstrual age (PMA) of 35+2 (25+3- 43+1) weeks following ethics approval and parental consent. Constrained spherical deconvolution and probabilistic tractography implemented in MRtrix3 were used to delineate WM tracts. Data were analysed in SPSS v.24 using Pearson’s correlation and Bonferroni correction applied to reported p-values. Participants with congenital malformations, focal lesions, severe motion artefact on MRI or neurodevelopmental outcome scores < 85 on the Bayley III Scales at 2 years were excluded.
Results: PMA was positively correlated with FA, ND and ODI and negatively correlated with MD in WM tracts (Table 1).
Table 1: Correlation between post menstrual age at scan and diffusion matters in white matter tracts. * significant, p<0.00125
Conclusion: This is the first study using NODDI to describe WM maturation in neonates with normal developmental outcomes in early childhood. NODDI enables us to appreciate contributions of neuronal and cell density and dispersion on FA values, enhancing biological interpretation of diffusion data, which is key to defining robust imaging markers.
Corresponding author: jessica.kimpton@doctors.org.uk
References
1. Zhang, H. et al. NODDI: practical in vivo neurite orientation dispersion and density imaging of the human brain. NeuroImage 61, 1000-1016 (2012).