Recent advances in diffusion neuroimaging: applications in the developing preterm brain

Abstract

Measures obtained from diffusion-weighted imaging provide objective indices of white matter development and injury in the developing preterm brain. To date, diffusion tensor imaging (DTI) has been used widely, highlighting differences in fractional anisotropy (FA) and mean diffusivity (MD) between preterm infants at term and healthy term controls; altered white matter development associated with a number of perinatal risk factors; and correlations between FA values in the white matter in the neonatal period and subsequent neurodevelopmental outcome. Recent developments, including neurite orientation dispersion and density imaging (NODDI) and fixel-based analysis (FBA), enable white matter microstructure to be assessed in detail. Constrained spherical deconvolution (CSD) enables multiple fibre populations in an imaging voxel to be resolved and allows delineation of fibres that traverse regions of fibre-crossings, such as the arcuate fasciculus and cerebellar–cortical pathways. This review summarises DTI findings in the preterm brain and discusses initial findings in this population using CSD, NODDI, and FBA.

Peak Width of Skeletonized Water Diffusion MRI in the Neonatal Brain

“…Increased PSAD in preterm infants at term equivalent age is consistent with altered axonal integrity, which is a feature of white matter disease in preterm infants. PSFA was the only metric that did not show a significant difference between groups, although there was a histogram shift (Table 3) such that term infants do have higher mean FA across the skeleton, which is a consistent finding across studies (4). All the metrics, with exception of the PSFA and PSODI, achieved high accuracy (≥70%) in the classification task of preterm vs. term brain images.…”

“…Peak width of skeletonized DTI and NODDI metrics have potential to be useful biomarkers of preterm brain dysmaturation because several are known to be altered throughout white matter in association with preterm birth. Specifically, low FA and increased MD occur throughout the white matter in preterm infants at term equivalent age compared with term-born infants (4,(17)(18)(19)(20), and NDI at term equivalent age it is negatively correlated with gestational age at birth (8). Additional advantages are that this framework is fully automated, only requires a single diffusion MRI acquisition, is computationally inexpensive, and has high inter-scanner reproducibility so could be used in clinical settings and for multi-center clinical trials (14).…”

“…Preterm birth is closely associated with a phenotype that includes cognitive impairment in childhood and cerebral white matter disease. White matter disease is apparent as diffuse changes in signal intensity on conventional MRI (1,2), and alterations in diffusion MRI parameters based on the diffusion tensor [fractional anisotropy (FA), and mean, axial, and radial diffusivities, (MD, AD, RD)], and more recently, metrics based on biophysical models, such as neurite orientation and dispersion imaging (NODDI) (3,4). These metrics have proven useful for making inferences about microstructural alteration of white matter that characterizes dysmaturity associated with preterm birth, for investigating upstream pathways to typical / atypical brain development, and for studying the anatomical bases of subsequent cognitive function in early life (5)(6)(7)(8)(9)(10)(11)(12)(13).…”

New Paradigm in Abilitation of Premature Children with Perinatal Pathology — Therapeutic Stages Personalization: Cohort Study

“…Помимо этого, в нашем исследовании у всех пациентов МРТ выполнялась не более 1-2 раз по стандартной методике; детального МРТ-исследования формирования нейрональных связей в динамике (МРТ-трактография) не проводилось. Как известно, подобные исследования способны выявить тонкие нарушения формирования структуры белого мозгового вещества, которые у недоношенных могут быть связаны с негрубыми моторными дефектами [26].…”

A framework for multi-component analysis of diffusion MRI data over the neonatal period

“…Prior work in neonatal group-analysis of diffusion data aims to establish and improve inter-subject correspondence, increase sensitivity and robustness to large shape and intensity changes during development, increase specificity to tissue classes and white matter (WM) fibre tracts, and to build models with interpretable parameters with respect to biological tissue properties. A comprehensive review of diffusion models and analysis methods is beyond the scope of this manuscript, see (Novikov et al., 2018) for a review on microstructure modelling in diffusion MRI (Dell’Acqua and Tournier, 2018), for a discussion of spherical deconvolution techniques, and (Pecheva et al., 2018) for a summary of analysis techniques applied to neonatal data.…”