Keywords: Normal Development, Microstructure, Development, cortex, childhood, adolescence

Motivation: The adolescent brain has been well described using MRI, revealing ongoing cortical thinning and volume loss. But which underlying cellular properties drive these changes?

Goal(s): To model developmental patterns of soma and neurite architecture in the human cerebral cortex.

Approach: We quantified in vivo cortical neurite and soma microstructure in a sample of children and adolescents aged 8-18 years. We then analysed two human gene expression databases to determine cell-type specific profiles underlying these MR-based changes.

Results: Developmental increases in neurite density and reductions in soma radius suggest increasing cortical oligodendrocyte density, supporting the model of protracted intra-cortical myelination throughout the adolescent period.

Impact: Our novel study suggests that ongoing intracortical myelination underpins developmental patterns of cortical neurite and soma microstructure. Once thought to be driven by synaptic pruning, increasing cortical oligodendrocyte density may underlie previously reported patterns of cortical volume loss in adolescence.

Keywords: Fetal, Diffusion/other diffusion imaging techniques, Brain, Simulation

Motivation: Computational models may help to decipher the neuroscientific mechanisms of cortical folding. Past simulations relied on histology or ex-vivo MRI data, which may not fully capture the complexity of in-utero brain development.

Goal(s): To build a simulation model leveraging in-utero MRI data to elucidate how cortical microstructures impact fetal brain gyrification.

Approach: Based on diffusion MRI-measured microstructures, we simulated cortical folding in the right temporal lobe using a computational model.

Results: Differences in fiber density between sulci and gyri are critical for folding initialization and development, linked to regional differences in dendritic arborization. Simulation results agreed with experimentally measured fetal brain morphology.

Impact: Our work introduced a novel computational model that utilized in-utero MRI data to simulate the cortical folding process of the human fetal brain, suggesting local differences in dendritic arborization may be one of the driving forces of cortical folding.

Keywords: Adolescents, Pediatric, Congenital Heart Disease Neurodevelopment Cerebrospinal Fluid Flow

Motivation: Examine cerebrospinal fluid (CSF) flow abnormalities in congenital heart disease (CHD) and develop an evaluation method to measure the CSF flow variance over the entire CSF flow cycle.

Goal(s): Determine CSF flow difference between CHD and healthy controls. Evaluate effectiveness of new method to measure CSF flow variance.

Approach: Use phase contrast MRI to acquire CSF flow velocity over the pulsatile flow cycle. Model consensus CSF flow of study cohort and calculate each participant’s flow variance using root mean square deviation.

Results: CHD had greater pulsatile CSF flow variance, especially in CHD with single ventricle. Higher flow variance predicted poor working memory outcomes.

Impact: This study expands our understanding of CSF flow abnormality in CHD and its potential for predicting executive function deficit. A new method measuring CSF flow variance over the entire flow cycle offers an evaluation of CSF flow abnormalities more comprehensively.

Keywords: Neuro, Brain, shunt, hydrocephalus

Motivation: We investigate a new approach to evaluating ventricular shunt function using phase-contrast magnetic resonance imaging (PC-MRI).

Goal(s): Our goal was to demonstrate the rapid (96-second) sequence as a practical adjunct for determining shunt function non-invasively.

Approach: An MRI phantom was constructed to assess CSF flows between 0-24 cc/hr while in vivo studies measured 21 consecutive patients.

Results: The PC-MRI calibration curve demonstrates a slightly non-linear relationship between flow output by pump and PC-MRI measured velocity. The in vivo patient studies flows ranged between 7 and 54 cc/hr.

Impact: Our work shows that PC-MRI is a non-invasive method for the measurement of CSF flow through the shunt in patients with hydrocephalus. Our work shows that PC-MRI is a promising addition to the clinical setting.

Keywords: Neuro, Brain

Motivation: Whether there exist association between glymphatic/white matter impairment and postoperative outcomes of paediatric hydrocephalus.

Goal(s): We tried to investigate the glymphatic and white matter abnormalities in paediatric hydrocephalus using MRI metrics.

Approach: Fifty-five children with hydrocephalus who underwent MRI and ventriculoperitoneal shunt surgery were prospectively enrolled. DTI metrics were analyzed.

Results: Compared with controls, DTI-ALPS index decreased before surgery and recovered after surgery. The preoperative and postoperative DTI-ALPS index and FA in association fibres could predict the short-term motor and long-term cognition outcomes, respectively.

Impact: The DTI-ALPS index and FA could be a sensitive biomarker of underlying neuroanatomical changes and developmental outcomes, which would benefit the decision-making of treatment plans.

Keywords: Normal Development, Perfusion, infant; cortical gradient; hierarchy; behavior; neuroscience;

Motivation: Infant cerebral blood flow (CBF) delivers nutrients to meet the brain’s energy demand for the fastest period of brain development across lifespan.

Goal(s): The presented study delineates the organizing principle of whole-brain CBF dynamics during infancy.

Approach: We optimized a state-of-the-art pseudo-continuous-arterial-spin-labeled (pCASL) sequence to obtain high-resolution spatiotemporal dynamics of infant CBF at isotropic 2.5mm.

Results: We revealed infant physiological heterogeneity and found the emergence of the limbic-sensorimotor-association cortical gradient based on CBF. Infant regional CBF changes were also associated with their improved real-world developmental functioning. These normative charts of infant CBF can serve as atlases for research and clinical care.

Impact: Capitalizing on a 3D multi-shot stack-of-spirals pCASL, we acquired the highest-resolution infant CBF maps available to date, discovered the emergence of the limbic-sensorimotor-association cortical gradient in infancy, and provide a standardized reference for infant CBF.

Keywords: Neuro, Arterial spin labelling

Motivation: OSA Children show cognitive and behavioral impairments along with brain tissue changes. The status of CBF, which may contribute to brain changes impacting cognitive and behavioral issues in pediatric OSA, is unknown.

Goal(s): Our goal was to examine CBF, brain volume, and microstructural changes in pediatric OSA and evaluate associations between CBF, cognition, and behavioral issues.

Approach: We used ANCOVA to compare CBF and brain tissue changes between OSA and controls, and partial correlations for associations.

Results: We observed reduced CBF in pediatric-OSA and associations of CBF with behavioral and cognitive issues, which may contribute to OSA pathogenesis.

Impact: This study showed altered cerebral blood flow and its associations with abnormal behavioral and cognitive functions in children with OSA, which have never been studied before. The reduced regional flow may lead to further neural damage in the condition.

Keywords: Neuro, Brain, Autism, Neurodevelopment

Motivation: The axon morphology underlying the evolution of Autism Spectrum Disorder (ASD) symptoms during early childhood is still enigmatic. 

Goal(s):  To uncover the developmental patterns of axon density in early childhood of ASD , and further explore their relationships with clinical measures in ASD.

Approach: We used a multi-shell diffusion MRI dataset of 1- to 7-year-old children (including 156 ASD , 48 developmental delay/intellectual disability and 160 Typical Development).

Results: ASD reserved three white matter clusters during early childhood as TD, but exhibited abnormal curves with various developmental stages. The development-stage-specific associations between axon density and clinical measures were elucidated in ASD.

Impact: Whilst reserving uneven spatial layouts of white matter development during early childhood as TD, ASD exhibited developmental curves with altered growth rates and distinct clinical associations in different developmental stages, elucidating potential targets for early diagnoses and interventions in ASD.

Keywords: Adolescents, Adolescents, screen use, reading, brain volume, brain development

Motivation: The causal relationships between screen use and mental health were not clear.

Goal(s): We used genetic, imaging, and questionnaire data from ABCD study to investigate the causal relationships between screen use and mental health in early adolescents.

Approach: One-sample Mendelian randomization analysis.

Results: We found a direct causal relationship between screen use and behavior problems and an indirect effect between screen use and brain volume by the changes in reading habits. 

Impact: These findings provide new evidence for a causal influence of screen use and reading habits on brain development and highlight the importance of monitoring media use and related habits change in children.