Keywords: Neonatal, Oxygenation

Motivation: Over 40% of neonates with moderate or severe hypoxic-ischemic-encephalopathy (HIE) still suffer from death, disability or neurodevelopmental delay after standard hypothermia treatment. Assessment of the brain’s oxygen metabolism may provide useful biomarkers to identify the risk of permanent neurologic injury and determine the necessity of adjuvant treatments.

Goal(s): To evaluate cerebral oxygen-extraction-fraction (OEF) and cerebral-metabolic-rate-of-oxygen (CMRO2) in neonates with HIE in comparison with healthy newborns.

Approach: We measured OEF and CMRO2 in 42 neonates with HIE and 52 healthy newborns.

Results: Neonates with HIE exhibited diminished OEF and CMRO2. Furthermore, a lower OEF predicted a longer stay in the neonatal ICU.

Impact: The brain’s physiological parameters such as oxygen-extraction-fraction can provide additional information (beyond standard clinical indices) for cerebral injury evaluation and treatment planning for hypoxic-ischemic-encephalopathy.

Keywords: Neonatal, CEST & MT

Motivation: Chemical exchange saturation transfer (CEST) has been employed for studying pH changes in acute phase of neonatal arterial ischemic stroke (NAIS), but not for long-term effects.

Goal(s): This study aimed to achieve longitudinal monitoring of NAIS evolution.

Approach: We constructed a 7-day-old NAIS rat model and explored the changes of brain metabolites by CEST-MRI. Contrast maps for contributing metabolites were calculated using Lorentzian Difference (LD) methods.

Results: All LD-quantified CEST contrast maps exhibit significant increase as age growth, in both sham group and the contralateral brain in NAIS group; Whereas the ischemic hemisphere displayed lower signals than the contralateral sides in NAIS group .

Impact: CEST signals displayed significant elevation over from 3h to 5w after surgery for both sham group and the contralateral brain tissue in NAIS group. This suggests the potential of CEST in sensitive and comprehensive assessment in NAIS diagnosis and management.  

Keywords: Neonatal, Pediatric

Motivation: Hypoxic ischemic encephalopathy (HIE) is the most important reason for morbidity and mortality in full-term infants.

Goal(s): This study aimed to investigate the clinical value of 3DASL perfusion imaging for the early diagnosis and prognosis of HIE in full-term neonates.

Approach: This study recruited 40 full-term HIE neonates and 40 healthy controls. Cerebral blood flow (CBF) values of bilateral frontal lobes, basal ganglia, thalamus were measured for comparison.

Results: The HIE groups showed significant decreased CBF values in the frontal lobes but significantly increased CBF values in basal ganglia and thalamus as compared to the control group.

Impact: We observed significant group differences between HIE neonates and healthy controls. 3DASL could reflect abnormal changes of cerebral perfusion in HIE infants and demonstrated the clinical value for early diagnosis and diagnosis of HIE.

Keywords: Neonatal, White Matter

Motivation: As the last myelinated structure, SWM is most affected by prematurity. Early exposure to the environment might injure the organization of SWM and lead to psychiatric disorders later in life.

Goal(s): To detect the impact of both preterm birth and “abnormal” brain injury on SWM microstructure.

Approach: TBSS method was used to track SWM in preterm infants of different degrees. The study aimed to detect changes in diffusion indices over time and identify distinct manifestations within the brain injury group.

Results: We were surprised to find that different degrees of preterm birth have different effects on the microstructure of superficial white matter.

Impact: The dose-dependent effect of preterm birth on SWM microstructure/developmental pattern. Further study the dynamic developmental association between SWM structure and neurodevelopmental outcomes in elderly children to gain a deeper understanding of the role of SWM in brain functional development.

Keywords: Neonatal, Neonatal

Motivation: To explore high-risk pregnancy effects on premature infant brain development. Conditions like preeclampsia, gestational diabetes, and thyroid dysfunction can profoundly impact fetal brain development.

Goal(s): To evaluate the correlation between synthetic MRI and Doppler ultrasound in assessing brain development in high-risk pregnancies.

Approach: 54 infants from high-risk pregnancies and 50 from low-risk pregnancies were studied, analyzing various brain regions and blood flow parameters.

Results: Findings indicate moderate correlations between synthetic MRI and Doppler ultrasound data, providing a comprehensive assessment of premature infant brain development in high-risk pregnancies, with specific MRI and blood flow correlations.

Impact: This study's findings expand our understanding of high-risk pregnancy effects on infant brain development. They offer clinicians a valuable tool for early intervention, potentially improving outcomes for premature infants born to high-risk mothers.

Keywords: Fetal, Brain

Motivation: MRI is crucial for the diagnosis and prognosis of hypoxic-ischemic encephalopathy (HIE). High-resolution imaging benefits the detection of subtle lesions. However, neonates may not tolerate lengthy scans .

Goal(s): To obtain ultrahigh resolution brain diffusion-weighted MR images(DWIs) within a feasible time frame to detect lesions invisible on images acquired using standard clinical protocols.

Approach: One b=0 volume and six DWI volumes at submillimeter isotropic resolution (0.86×0.86×0.86 mm³) were acquired using the Generalized SLIce Dithered Enhanced Resolution Simultaneous MultiSlice (gSlider-SMS) sequence, in addition to standard protocols.

Results: Ischemic lesions and cytotoxic edema invisible on standard clinical images were found on submillimeter resolution diffusion MRI data.

Impact: Submillimeter isotropic resolution diffusion MR images show lesions invisible on standard clinical images, which helps diagnose HIE earlier and more accurately for timely and appropriate treatment, as well as provides new biomarkers for accurate HIE staging.

Keywords: Neonatal, Neonatal

Motivation: There is currently no high contrast structural T₁-weighted protocol available for neonatal imaging at ultrahigh field (7T), as the longer T₁ relaxation times make existing protocols optimized for older subjects unsuitable.

Goal(s): To produce submillimeter T₁-weighted images for neonates at 7T in a clinically feasible scan time.

Approach: We optimised a T₁-weighted MP2RAGE protocol using the genetic algorithm for constrained optimisation while accounting for transmit field inhomogeneities.

Results: 3D whole-brain images with 0.65-0.8mm isotropic resolution were acquired in under 6-7 minutes from 3 infants. Quantitative T₁ maps were produced using an in-house fitting algorithm.

Impact: We describe the first neonatal optimised MP2RAGE protocol for acquiring high-contrast submillimeter-resolution images with full-brain coverage that are relatively insensitive to transmit field inhomogeneities.  

Keywords: Neonatal, Brain Connectivity, structure-function coupling

Motivation: Structure-function coupling (SFC) has been proposed to decode the relationship between anatomical structure and neural activity, but how SFC develops in the perinatal period remains largely unknown.

Goal(s): To establish typical SFC map at birth and portray its development during the perinatal period.

Approach: SFC of neonatal brains from 26 to 45 postmenstrual weeks were characterized using the dHCP data, and compared to that of adults. The developmental trajectories were depicted by GLM. 

Results: SFC at birth already demonstrated a sensorimotor-to-association pattern but were immature in somatomotor and frontoparietal networks compared to adults. SFC increased extensively and fastest in visual and limbic networks.

Impact: This study fills a gap in the SFC research during early development. Our findings characterized the brain connectome in term- and preterm-born neonates, revealing that visual regions developed earlier than somatomotor regions.

Keywords: Neonatal, Spectroscopy

Motivation: Alterations in brain metabolism before and after surgical repair of congenital heart disease is not well studied.

Goal(s): To investigate changes in key brain metabolites and primary neurotransmitters before and after cardiac surgery using ¹H-MRS.

Approach: Data were acquired in the cerebellum, right basal ganglia and right frontal lobe using MEGA-PRESS in 3T.

Results: Measurements of myo-inositol (mI) in the cerebellum were significantly higher in the preoperative CHD group compared to the healthy controls. γ-Aminobutyric acid (GABA) measurements were significantly higher in the right basal ganglia in the postoperative CHD group compared to the preoperative group.

Impact: Expanded investigation of brain biochemistry in neonates with congenital heart disease has revealed dynamic changes in key metabolites before and after cardiac repair, especially in key neurotransmitters GABA and mI which are known to play important roles in neurodevelopmental disabilities.

Keywords: Neonatal, Quantitative Susceptibility mapping

Motivation: Estimating iron and myelin contents in the newborn brain can be used to access neurodevelopment, but is challenging with conventional quantitative susceptibility mapping.

Goal(s): To separate positive and negative susceptibilities in the newborn brain and investigate differences between preterm and full-term newborns.

Approach: A total of 22 full-term and 10 preterm newborns were studied using quantitative susceptibility mapping with R2*-based source separation. Mean susceptibilities within 10 regions-of-interests were compared between full-term and preterm newborns.

Results: Preterm brains showed less positive and negative susceptibilities, compared to the full-term brains.

Impact: This study suggests that positive and negative magnetic susceptibilities in the newborn brain may be estimated individually using quantitative susceptibility mapping with source separation and may be used to identify early deviations from normal neurodevelopment in preterm-born infants.

Keywords: Neuro, MR Value

Motivation: Brain injury induced by neonatal hyperbilirubinemia is an important cause of abnormal development of infant nervous system. The traditional use of serum total bilirubin as a diagnostic marker is inconsistent and imprecise.

Goal(s): This study aims to investigate the relationship between different levels of bilirubin and quantitative parameters of SyMRI with hyperbilirubinemia.

Approach: A total of 107 NHB and 22 healthy infants were recruited in the study. Obtain T1, T2, and PD values by scanning SyMRI sequences.

Results: There were significant difference in T1 values of globus pallidus and cerebral peduncle at different levels of TSB, and there were negative correlation.

Impact: The assessment of neonatal bilirubin encephalopathy with increased signals from the pallidus has a high degree of subjectivity. SyMRI can reflect biological information through quantitative parameters, providing objective basis for the early diagnosis of NHB.

Keywords: MR Fingerprinting, MR Fingerprinting, Neonatal

Motivation: Motion artifact of MR Fingerprinting (MRF) cannot be recognized visually, but it affects quantitative values severely.

Goal(s): We aimed to assess the impact of motion in MRF and propose an objective motion-detection method.

Approach: We utilized Spatiotemporal Residuals (STR) from MRF-acquired signals and compared them with motion assessments in neonatal clinical practice.

Results: Our results revealed that motion significantly affects the accuracy of both T1 and T2 values. By applying an appropriate threshold to the standard deviation of STR, we achieved highly accurate motion detection equivalent to expert visual judgment, which leads to robust accuracy of quantitative values.

Impact: Our method to detect motion from MRF signals enables an objective assessment of the presence or absence of motion in MRF data. Consequently, this method facilitates the evaluation of the reliability of quantitative MRF images in clinical settings.

Keywords: Neonatal, Normal development, early preterm brain development

Motivation: BOLD signal variability (BOLD-SD) has emerged as a measure for assessing brain function, but little is known regarding its biological significance. 

Goal(s): Demonstrate that cortical BOLD-SD modifications are accompanied by structural intracortical maturational changes. Elucidate brain networks undergoing the most important maturational changes during early development.

Approach: Longitudinal brain MRI acquisition in preterm infants at 33 and 40 weeks’ gestational age. Assessment of cortical BOLD-SD and NODDI indices longitudinal modifications per brain network.

Results: A significant longitudinal cortical BOLD-SD increase is observed in primary sensory networks and Default-Mode-Network, accompanied by a decreased NDI (neurite-density-index) and/or increased ODI (orientation-dispersion-index), reflecting concomitant structural intracortical maturation.

Impact: During early brain development, the BOLD signal variability increase in resting-state networks was associated to underlying structural intracortical maturational changes and thus it can be considered as a marker of cortical maturation.

Keywords: Neuro, Brain Connectivity, Neurodevelopment, fMRI, Music

Motivation: Instrumental music and singing differ due to the vocal component of the sung melody and present distinct neural processing pathways, though its developmental origins remain unclear.

Goal(s): This study explores the early development of music vs singing brain processing.

Approach: Dynamic PPI-CAPs approach was applied to longitudinal fMRI data of preterm infants at 33- and 40-weeks gestational age.

Results: Singing elicited a stronger activation of salience and language-related networks, while music elicited limbic networks. Default-mode network and right temporal gyrus were elicited for both stimuli longitudinally. Visual network is also involved for both stimuli but only at term-equivalent age.

Impact: This study explores the longitudinal early development of neural processing networks in the context of instrumental and vocal music stimuli and shows that preterm infants already present a specialized processing for these different stimuli.

Keywords: Neuro, Brain

Motivation: Preterm male present high risk for neurodevelopmental disability. However, sex differences in preterm neurodevelopmental characterization is not yet known.

Goal(s): Investigate sex differences in neurodevelopmental evolution of preterm by exploring the postnatal age-related changes of brain white matter (WM) and neurobehavioral abilities.

Approach: The diffusion tensor imaging (DTI) parameter FA was applied to indirectly reflect the changes of brain white matter microstructure.

Results: The FA in preterm neonates is lower than term neonates which increased with postnatal age in both. Male presented significantly higher growth rate in certain brain regions compared with female especially for preterm male. 

Impact: Preterm male showed higher growth rate in certain brain regions which indicate a “catch-up” pattern toward the term neonates and this finding may suggest that certain intervention would be expected to work well in improving the preterm male outcome.