Assessing white matter microstructure of the newborn with multi-shell diffusion MRI and biophysical compartment models

Abstract

Brain white matter connections have become a focus of major interest with important maturational processes occurring in newborns. To study the complex microstructural developmental changes in-vivo, it is imperative that non-invasive neuroimaging approaches are developed for this age-group. Multi-b-value diffusion weighted imaging data were acquired in 13 newborns, and the biophysical compartment diffusion models CHARMED-light and NODDI, providing new microstructural parameters such as intra-neurite volume fraction (νin) and neurite orientation dispersion index (ODI), were developed for newborn data. Comparative analysis was performed and twenty ROIs in the white matter were investigated. Diffusion tensor imaging and both biophysical compartment models highlighted the compact and oriented structure of the corpus-callosum with the highest FA and νin values and the smallest ODI values. We could clearly differentiate, using the FA, νin and ODI, the posterior and anterior internal capsule representing similar cellular structure but with different maturation (i.e. partially myelinated and absence of myelin, respectively). Late maturing regions (external capsule and periventricular crossroads of pathways) had lower νin values, but displayed significant differences in ODI. The compartmented models CHARMED-light and NODDI bring new indices corroborating the cellular architectures, with the lowest νin, reflecting the late maturation of areas with thin non-myelinated fibers, and with highest ODI indicating the presence of fiber crossings and fanning. The application of biophysical compartment diffusion models adds new insights to the brain white matter development in vivo.

Age-related microstructural differences quantified using myelin water imaging and advanced diffusion MRI

“…These can be seen as independent factors influencing anisotropy and provide a more biologically intuitive model of diffusion changes. NODDI has been successfully applied in previous studies investigating pathologic changes (Billiet et al, 2014;Lally et al, 2014;Winston et al, 2014) and neonates (Jelescu et al, 2015;Kunz et al, 2014;Melbourne et al, 2013) but has not yet been used prospectively in healthy aging.…”

Sensitivity of multi-shell NODDI to multiple sclerosis white matter changes: a pilot study

“…NODDI parameters have recently been shown to provide greater contrast than DTI for the detection of subtle cortical abnormalities in people with epilepsy (Winston et al, 2014). NODDI metrics have also been shown to be more informative than DTI in describing differences between main fiber tracts in terms of intra-axonal water fraction and axon dispersion when used to study the time-course of maturation in the developing brain (Kunz et al, 2014). In this pilot study, we applied NODDI to a small cohort of MS patients and age-and gender-matched healthy controls (HCs).…”

Neurite orientation dispersion and density imaging of the healthy cervical spinal cord in vivo

“…On the other hand, high orientation dispersion occurs when neurites are dispersed in space and their orientations vary considerably from each other. In practice, NODDI can be performed in a clinically feasible time and it was recently applied with encouraging results to brain tumour (Wen et al, 2014), multiple sclerosis (MS) (Magnollay et al, 2014;Schneider et al, 2014), in vivo g-ratio estimation (Campbell et al, 2014), focal cortical dysplasia (Winston et al, 2014), NeuroImage 111 (2015) [590][591][592][593][594][595][596][597][598][599][600][601] neurofibromatosis (Billiet et al, 2014), neonatal encephalopathy (Lally et al, 2014) and healthy newborn brain (Kunz et al, 2014).…”