Neonatal Magnetic Resonance Imaging Research Articles

Neonatal hypoxic-ischaemic encephalopathy: Motor impairment beyond cerebral palsy

Research investigating neuromotor function in the absence of cerebral palsy (CP) for children who had neonatal HIE is limited.To investigate school-age neurological and neuromotor function, and correlations with attention, neonatal Magnetic Resonance Imaging (MRI), and neuromotor assessments at toddler age.Twenty-seven children with neonatal HIE without CP who underwent hypothermia treatment and a comparison group of 20 children were assessed at age 5-7 years for Minor Neurological Dysfunction (MND; simplified Touwen), motor skills (Movement Assessment Battery for Children-2; MABC-2), parental concern over motor function (MABC Checklist), general cognition (Wechsler Preschool and Primary Scale of Intelligence-IV, WPPSI), and attention (DuPaul ADHD Rating Scale). Neurological examination and motor development, using Bayley-3 scales, at age 24-months was extracted from the clinical database. Clinical neonatal MRI was assessed for hypoxic-ischaemic injury.In the HIE group, MND was more prevalent (p = 0.026) and M-ABC performance (total score p = 0.006; balance subtest p = 0.008) was worse; parents were more concerned about children's motor function (p = 0.011). HIE group inattention scores were higher (p = 0.032), which correlated with lower MABC-2 scores (rs = -0.590, p = 0.004). Neurological examination at 24-months correlated with MND (rs = 0.437, p = 0.033); Bayley-3 motor scores did not correlate with M-ABC-2 scores (rs = 368, p = 0.133). Neonatal MRI findings were not associated with school-age MND (rs = 0.140, p = 0.523) or MABC-2 (rs = 0.300, p = 0.165).Children with neonatal HIE, without CP, treated with hypothermia may be more likely to develop MND and motor difficulties than typically developing peers. Inattention may contribute to motor performance. In the absence of CP, neonatal MRI and toddler age assessment of motor development have limited predictive value for school-age outcome. Since this was an exploratory study with a small sample size, findings should be confirmed by a definite larger study.

Long-term cognitive outcomes in term newborns with watershed injury caused by neonatal encephalopathy

BackgroundWe previously reported that increasing severity of watershed (WS) injury in neonatal magnetic resonance imaging (MRI) is associated with worse language outcomes in early childhood. In the present study, we investigated the relationship between neonatal injury patterns and cognitive profile in adolescents with neonatal encephalopathy.MethodsTerm neonates with encephalopathy were prospectively enrolled and imaged using brain MRI from 1999 to 2008. Neonatal brain injury was scored according to the degree of injury in WS and basal ganglia/thalamus (BG/T) areas. The children underwent a neurocognitive assessment and follow-up brain MRI at the age of 10–16 years. The relationship between neonatal brain injury patterns and adolescent cognitive outcomes was assessed.ResultsIn a cohort of 16 children, neonatal MRI showed WS injury in 7, BG/T injury in 2, and normal imaging in 7. Children with WS injury had lower estimated overall cognitive ability than those with normal imaging. Increasing WS injury score was associated with decreasing estimated overall cognitive ability, Perceptual Reasoning Index, and digit span score.ConclusionsChildren with the WS injury are at an increased risk of having problems in long-term intellectual ability. These cognitive outcomes may underlie early language difficulties seen in children with neonatal WS injury.ImpactAdolescents with a history of neonatal encephalopathy and watershed pattern of injury on neonatal brain magnetic resonance imaging (MRI) had lower overall cognitive ability, perceptual reasoning skills, and auditory working memory than those with normal neonatal imaging.Children with post-neonatal epilepsy and cerebral palsy had the worst cognitive outcomes.Watershed pattern of injury confers high long-term differences in intellectual ability.

Mildly Elevated Bilirubin Levels are Associated with Increased Magnetic Resonance Imaging Signal Intensity in the Basal Ganglia of Preterm Neonates.

This study aimed to test whether mildly elevated bilirubin levels in preterm infants are associated with increased signal intensity (SI) on magnetic resonance imaging (MRI) of the basal ganglia (BG). MRI was performed at term equivalent age in 55 postpreterm infants using a neonatal MRI 1-T scanner. SI of the BG was correlated with mild hyperbilirubinemia. BG MRI SI was significantly increased in infants with mild hyperbilirubinemia on T1-weighted image (T1; p = 0.0393) and T2-weighted image (T2; p = 0.0309). We found no effect of gestational age or sepsis on BG MRI intensity; however, there was a significant effect of acidosis on T1 (p = 0.0223) but not on T2 (p = 0.2316). Infants with combined hyperbilirubinemia and acidosis had the most significant increase in SI on both T1 and T2 respectively (p = 0.0072 and 0.0195, respectively). We found a positive association between increased BG MRI SI and mildly elevated bilirubin levels. The effect was greatly strengthened when hyperbilirubinemia was associated with acidosis. · Excessive bilirubin is neurotoxic to the neonatal brain. It is deposited in the BG.. · BG MRI SI is increased with bilirubin deposition.. · The premature brain is more vulnerable to bilirubin associated MRI changes..

Safety and effectiveness of intranasal dexmedetomidine together with midazolam for sedation in neonatal MRI.

Magnetic resonance imaging (MRI) has been consistently indicated as the imaging modality of choice in children and neonates. MRI is pivotal for the management and prognostication of different neonatal conditions including neonatal encephalopathy, preterm birth and congenital heart diseases. While feed and wrap technique may be used to perform MRI scans without sedation, this is not always possible due to MRI sensitivity to motion artifacts and long duration of the procedure.

Implementation of the Feed and Swaddle Technique as a Non-Pharmacological Strategy to Conduct Brain Magnetic Resonance Imaging in Very Low Birth Weight Infants

Purpose: Magnetic resonance imaging (MRI) is a useful tool for evaluating brain injury and maturation in preterm infants and often requires sedation to acquire images of sufficient quality. Infant sedation is often associated with adverse events, despite extreme precautions. In this study, the swaddling technique was investigated as an alternative non-pharmacological strategy to obtain brain MRIs of sufficient quality.Methods: We applied the feed and swaddle technique during routine brain MRI as a quality improvement project and compared its morbidity with that of sedation in a historic age-matched group. Seventy-nine very low birth weight infants in the neonatal intensive care unit of Ajou University Hospital (Suwon, Korea) were enrolled. Thirty-two (40.5%) infants were in the feed and swaddling group, and 47 (59.5%) were in the sedation group.Results: The morbidity associated with the cardiopulmonary system (swaddling group vs. sedation group: 53.13% [n=17] vs. 63.83% [n=30], P=0.723) and central nervous system (40.63% [n=13] vs. 29.79% [n=14], P=0.217) were not significantly different between groups. The MRI failure rate was not significantly different (swaddling group vs. sedation group: 12.5% [n=4] vs. 4.3% [n=2], P=0.174). The MRI scanning time was longer in the swaddling group than in the sedation group (76.5±20.3 minutes vs. 61.5±13.6 minutes, P=0.001). Cardiopulmonary adverse events were significantly less common in the swaddling group than in the sedation group (3.13% [n=1] vs. 34.04% [n=16], P=0.002).Conclusion: The success rate of MRI was comparable between the swaddling technique and sedation. Furthermore, despite the drawback of prolonged scan time, cardiopulmonary adverse events are fewer with swaddling than with sedative agents. Therefore, swaddling can be an alternative to sedation or anesthesia when performing neonatal MRI scans.

Survey of Acoustic Output in Neonatal Brain Protocols.

Auditory and non-auditory safety concerns associated with the appreciable sound levels inherent to magnetic resonance imaging (MRI) procedures exist for neonates. However, current gaps in knowledge preclude making an adequate risk assessment. To measure acoustic exposure (duration, intensity, and frequency) during neonatal brain MRI and compare these values to existing hearing safety limits and data. Phantom. Cylindrical doped water phantom. Neonatal brain protocols acquired at 1-3 T. Scans in the model protocol included a diffusion tensor imaging scan, a gradient echo, a three-dimensional (3D) fast spin echo, 3D fast spin-echo single-shots, a spin echo, a turbo spin echo, a 3D arterial spin labeling scan, and a susceptibility-weighted fast spin-echo scan. The sound pressure levels (SPLs), frequency profile, and durations of five neonatal brain protocols on five MR scanners (scanner A [3 T, whole-body], scanner B [1.5 T, whole-body], scanner C [1 T, dedicated neonatal], scanner D [1.5 T, whole-body], and scanner E [3 T, whole-body]) located at three different sites were recorded. The SPLs were then compared to the International Electrotechnical Commission (IEC) hearing safety limit and existing data of infant non-auditory responses to loud sounds to assess risk. Mann-Whitney U test to assess whether the dedicated neonatal scanner was quieter than the other machines. The average level A-weighted equivalent value (LAEQ) across all five MR scanners and scans was 92.88 dBA and the range of LAEQs across all five MR scanners and scans was 80.8-105.31 dBA. The duration of the recorded neonatal protocols maintained by neonatal scanning facilities (from scanners A, B, and C) ranged from 27:33 to 37:06 minutes. Neonatal protocol sound levels straddled existing notions of risk, exceeding sound levels known to cause non-auditory responses in neonates but not exceeding the IEC MRI SPL safety limit. 5 TECHNICAL EFFICACY: Stage 5.

Robust Cortical Thickness Morphometry of Neonatal Brain and Systematic Evaluation Using Multi-Site MRI Datasets.

The human brain grows the most dramatically during the perinatal and early post-natal periods, during which pre-term birth or perinatal injury that may alter brain structure and lead to developmental anomalies. Thus, characterizing cortical thickness of developing brains remains an important goal. However, this task is often complicated by inaccurate cortical surface extraction due to small-size brains. Here, we propose a novel complex framework for the reconstruction of neonatal WM and pial surfaces, accounting for large partial volumes due to small-size brains. The proposed approach relies only on T1-weighted images unlike previous T2-weighted image-based approaches while only T1-weighted images are sometimes available under the different clinical/research setting. Deep neural networks are first introduced to the neonatal magnetic resonance imaging (MRI) pipeline to address the mis-segmentation of brain tissues. Furthermore, this pipeline enhances cortical boundary delineation using combined models of the cerebrospinal fluid (CSF)/GM boundary detection with edge gradient information and a new skeletonization of sulcal folding where no CSF voxels are seen due to the limited resolution. We also proposed a systematic evaluation using three independent datasets comprising 736 pre-term and 97 term neonates. Qualitative assessment for reconstructed cortical surfaces shows that 86.9% are rated as accurate across the three site datasets. In addition, our landmark-based evaluation shows that the mean displacement of the cortical surfaces from the true boundaries was less than a voxel size (0.532 ± 0.035 mm). Evaluating the proposed pipeline (namely NEOCIVET 2.0) shows the robustness and reproducibility across different sites and different age-groups. The mean cortical thickness measured positively correlated with post-menstrual age (PMA) at scan (p < 0.0001); Cingulate cortical areas grew the most rapidly whereas the inferior temporal cortex grew the least rapidly. The range of the cortical thickness measured was biologically congruent (1.3 mm at 28 weeks of PMA to 1.8 mm at term equivalent). Cortical thickness measured on T1 MRI using NEOCIVET 2.0 was compared with that on T2 using the established dHCP pipeline. It was difficult to conclude that either T1 or T2 imaging is more ideal to construct cortical surfaces. NEOCIVET 2.0 has been open to the public through CBRAIN (https://mcin-cnim.ca/technology/cbrain/), a web-based platform for processing brain imaging data.

Early Diagnostics and Early Intervention in Neurodevelopmental Disorders-Age-Dependent Challenges and Opportunities.

This review discusses early diagnostics and early intervention in developmental disorders in the light of brain development. The best instruments for early detection of cerebral palsy (CP) with or without intellectual disability are neonatal magnetic resonance imaging, general movements assessment at 2–4 months and from 2–4 months onwards, the Hammersmith Infant Neurological Examination and Standardized Infant NeuroDevelopmental Assessment. Early detection of autism spectrum disorders (ASD) is difficult; its first signs emerge at the end of the first year. Prediction with the Modified Checklist for Autism in Toddlers and Infant Toddler Checklist is possible to some extent and improves during the second year, especially in children at familial risk of ASD. Thus, prediction improves substantially when transient brain structures have been replaced by permanent circuitries. At around 3 months the cortical subplate has dissolved in primary motor and sensory cortices; around 12 months the cortical subplate in prefrontal and parieto-temporal cortices and cerebellar external granular layer have disappeared. This review stresses that families are pivotal in early intervention. It summarizes evidence on the effectiveness of early intervention in medically fragile neonates, infants at low to moderate risk, infants with or at high risk of CP and with or at high risk of ASD.

Early Identification of Cerebral Palsy Using Neonatal MRI and General Movements Assessment in a Cohort of High-Risk Term Neonates

BackgroundCerebral palsy (CP) is the most common motor disability of childhood. Its early identification is an important priority for parents and is critical for access to early intervention resources, which may optimize function. MethodsA prospective cohort of term neonates at high risk for CP was assessed by neonatal magnetic resonance imaging (MRI) to determine myelination of the posterior limb of the internal capsule, General Movements Assessment to assess typical fidgety movements at age three months, and followed to at least age two years to determine diagnosis of CP based on neurological examination. ResultsSeven of 58 children developed CP (12%), two with moderate/severe CP. Sensitivity and specificity for abnormal myelination of the posterior limb of the internal capsule were (PLIC) was 29% and 94%, and for absent fidgety movements, 29% and 98%, respectively. Negative predictive value of both absent myelination of the PLIC and absent fidgety movements was 90% (79% to 96%) for any CP and 98% (90% to 100%) for moderate/severe CP cerebral palsy. None of the children with both normal PLIC and normal fidgety movements had moderate/severe CP. ConclusionNormal neonatal MRI and General Movements Assessment at age three months are reassuring that a high-risk term-born child is at low risk for moderate/severe CP. These results are important for counseling parents and individualizing therapy resources in the community.

Associations between Neonatal Magnetic Resonance Imaging and Short- and Long-Term Neurodevelopmental Outcomes in a Longitudinal Cohort of Very Preterm Children

To assess associations between neonatal brain injury assessed by magnetic resonance imaging and cognitive, motor, and behavioral outcomes at 2 and 10years of age, in a longitudinal cohort of children born very preterm. There were 112 children born at <32weeks of gestation who participated in a longitudinal prospective study on brain injury and neurodevelopmental outcome. Using the Kidokoro score, neonatal brain injury and altered brain growth in white matter, cortical and deep gray matter, and the cerebellum were assessed. Cognitive, motor, and behavioral outcomes were assessed during follow-up visits at both 2 (corrected) and 10years of age. After adjusting for perinatal factors and level of maternal education, the global brain abnormality score was associated with cognition (B=-1.306; P=.005), motor skills (B=-3.176; P<.001), and behavior (B=0.666; P=.005) at 2years of age, but was not associated with cognition at 10years of age. In the subgroup of children with a moderate-severe global brain abnormality score, magnetic resonance imaging was independently associated with cognitive impairment at 10years of age. For children with milder forms of brain injury, only birth weight and level of maternal education were associated with cognitive outcomes. Neonatal brain injury, assessed by a standardized scoring system, was associated with short-term neurodevelopmental outcomes, but only with motor skills and behavior in childhood. Environmental factors, such as level of maternal education, become more important for cognitive development as children grow older, especially for children with relatively mild neonatal brain injury.

Clinical Application of Postmortem Magnetic Resonance Imaging in Neonates

Background: Recent reports advocate the use of MRI either as a substitute for postmortem examinations or for a more targeted autopsy. Methods: A full-body postmortem MRI (pMRI) of infants was performed as early as possible after death, and findings were compared to clinical premortem diagnoses. Results: Thirty-one infants were scanned during the study period. Median gestation at birth was 34 weeks (ranges: 24–43). In 3 (10%) cases, no new findings were detected. In 2 (6%), new minor findings not related to the cause of death were detected, and in 17 (55%), new minor findings related to the cause of death were detected. New major findings related to the cause of death were detected in 4 (13%) cases, and new major findings not related to the cause of death were detected in 5 (16%) cases. In 3 (10%), findings thought to alter the perceived cause of death were detected. Overall, in 23 (74%) cases, pMRI findings reinforced the clinical premortem diagnoses. Conclusions: pMRI is a culturally accepted alternative when autopsy is not performed and can either reinforce, refute, or add to premortem clinical diagnoses.

Arterial spin labeling in neonatal magnetic resonance imaging - first experience and new observations.

PurposeArterial spin labeling (ASL) is a noninvasive non-contrast technique of perfusion imaging that uses endogenous water from the blood as the perfusion tracer, with very scant data on its use in neonates. The authors present the added value of ASL in the examined babies in their own material and discuss it in the light of the existing literature.Material and methodsDuring the first 10 months after the purchase of a new magnetic resonance imaging (MRI) scanner, 123 neonates were examined using it in an MR-compatible incubator, 117 of them had brain MRI, and in 104 ASL was incorporated in the routine protocol, which resulted in prolongation of the study time by approximately 4 minutes. 3D ASL sequence uses Pulsed Continuous Arterial Spin Labeling (PCASL; aka pseudo continuous) technique.ResultsThe quality of the cerebral blood flow (CBF) maps was good in all cases but 2 because all the babies were sedated. Apart from the knowledge about normal perfusion patterns in the preterm and term neonatal brains, the use of ASL sequence provided important additional information in 11 cases (10.8%): increased CBF correlating with electroencephalographic seizure localization in otherwise normal MRI (n = 1), increased CBF in the cortex without clinical information about seizures and with posthaemorrhagic changes (n = 1), increased CBF in the brain stem and decreased in the upper parts of the brain (n = 2), probably reflecting the homeostatic mechanism which allows preferential perfusion of the vital structures of the brain stem, hypoperfusion (n = 1) or hypoperfusion with peripheral hyperperfusion (n = 1) in the area of stroke, hypoperfusion of the posterior areas of the brain in the presence of subarachnoid or epidural haemorrhage (n = 3), significantly increased CBF in the presumed nidus of arteriovenous malformation causing haemorrhage (n = 1), and lack of perfusion in the supratentorial compartment in a case of suspected brain death (n = 1).ConclusionsOur short experience but relatively large volume of material encourages the use of ASL in routine neonatal MRI as a useful and non-time-consuming tool providing additional important clinical information in a significant percentage of cases.

Exploratory Assessment of the Relationship Between Hemoglobin Volume Phase Index, Magnetic Resonance Imaging, and Functional Outcome in Neonates with Hypoxic-Ischemic Encephalopathy.

Near-infrared spectroscopy (NIRS)-based measures of cerebral autoregulation (CAR) can potentially identify neonates with hypoxic-ischemic encephalopathy (HIE) who are at greatest risk of irreversible brain injury. However, modest predictive abilities have precluded previously described metrics from entering clinical care. We previously validated a novel autoregulation metric in a piglet model of induced hypotension called the hemoglobin volume phase index (HVP). The objective of this study was to evaluate the clinical ability of the HVP to predict adverse outcomes neonates with HIE. This is a prospective study of neonates with HIE who underwent therapeutic hypothermia (TH) at a level 4 neonatal intensive care unit (NICU). Continuous cerebral NIRS and mean arterial blood pressure (MAP) from indwelling arterial catheters were measured during TH and through rewarming. Multivariate autoregressive process was used to calculate the coherence between MAP and the sum total of the oxy- and deoxygenated Hb densities (HbT), a surrogate measure of cerebral blood volume (CBV). The HVP was calculated as the cosine-transformed phase shift at the frequency of maximal MAP-HbT coherence. Brain injury was assessed by neonatal magnetic resonance imaging (MRI), and developmental outcomes were assessed by the Bayley Scales of Infant Development (BSID-III) at 15-30months. The ability of the HVP to predict (a) death or severe brain injury by MRI and (b) death or significant developmental delay was assessed using logistic regression analyses. In total, 50 neonates with moderate or severe HIE were monitored. Median HVP was higher, representing more dysfunctional autoregulation, in infants who had adverse outcomes. After adjusting for sex and encephalopathy grade at presentation, HVP at 21-24 and 24-27h of life predicted death or brain injury by MRI (21-24h: OR 8.8, p = 0.037; 24-27h: OR 31, p = 0.011) and death or developmental delay at 15-30months (21-24h: OR 11.8, p = 0.05; 24-27h: OR 15, p = 0.035). Based on this pilot study of neonates with HIE, HVP merits further study as an indicator of death or severe brain injury on neonatal MRI and neurodevelopmental delay in early childhood. Larger studies are warranted for further clinical validation of the HVP to evaluate cerebral autoregulation following HIE.

Risk for infantile spasms after acute symptomatic neonatal seizures.

Infantile spasms (IS) is a severe epilepsy in early childhood. Early treatment of IS provides the best chance of seizure remission and favorable developmental outcome. We aimed to develop a prediction rule to accurately predict which neonates with acute symptomatic seizures will develop IS. We used data from the Neonatal Seizure Registry, a prospective, multicenter cohort of infants with acute symptomatic neonatal seizures born from July 2015 to March 2018. Neonates with acute symptomatic seizures who received clinical electroencephalography (EEG) and magnetic resonance imaging (MRI) and were younger than 2years of age at the time of enrollment were included. We evaluated the association of neonatal EEG, MRI, and clinical factors with subsequent IS using bivariate analysis and best subsets logistic regression. We selected a final model through a consensus process that balanced statistical significance with clinical relevance. IS developed in 12 of 204 infants (6%). Multiple potential predictors were associated with IS, including Apgar scores, EEG features, seizure characteristics, MRI abnormalities, and clinical status at hospital discharge. The final model included three risk factors: (a) severely abnormal EEG or ≥3days with seizures recorded on EEG, (b) deep gray or brainstem injury on MRI, and (c) abnormal tone on discharge exam. The stratified risk of IS was the following: no factors 0% (0/82, 95% confidence interval [CI] 0%-4%), one or two factors 4% (4/108, 95% CI 1%-9%), and all three factors 57% (8/14, 95% CI 29%-83%). IS risk after acute symptomatic neonatal seizures can be stratified using commonly available clinical data. No child without risk factors, vs >50% of those with all three factors, developed IS. This risk prediction rule may be valuable for clinical counseling as well as for selecting participants for clinical trials to prevent post-neonatal epilepsy. This tailored approach may lead to earlier diagnosis and treatment and improve outcomes for a devastating early life epilepsy.

Rapid Magnetic Resonance Imaging of the Spine in Neonates with Spinal Dysraphism

The use of nonsedated T2-weighted Half-Fourier Acquisition Single-shot Turbo spin Echo magnetic resonance imaging (MRI) sequences in screening for spinal cord syrinx in neonates with spinal dysraphism has not been reported in the literature. We sought to review our experience using T2-weighted Half-Fourier Acquisition Single-shot Turbo spin Echo imaging of the spine (i.e., rapid spine MRI) in nonsedated neonates for detecting spinal cord syrinx in neonates with spinal dysraphism. We performed a retrospective search of our radiology database for neonates with spinal dysraphism who had rapid spine MRI between May 2017 and February 2020. The images were reviewed in conjunction with clinical findings and standard spine imaging, when available. Thirty studies (in 29 neonates) fulfilled our inclusion criteria. Of the 26 neonates with myelomeningocele, 5 of them (19%) had spinal cord syrinx identified on neonatal rapid spine MRI. An additional 2 patients developed syrinx by 2 years of age. Potential pitfalls identified in interpreting rapid spine MRI include motion artifacts and distinguishing a severe holocord syrinx from a truncated spinal cord. Rapid spine MRI acquired without sedation or anesthesia may be used as a screening technique to detect spinal cord syrinx in neonates with spinal dysraphism.

Head Ultrasound Resistive Indices Are Associated With Brain Injury on Diffusion Tensor Imaging Magnetic Resonance Imaging in Neonates With Hypoxic-Ischemic Encephalopathy.

Neonatal hypoxic-ischemic encephalopathy (HIE) is associated with dysfunctional cerebral autoregulation. Resistive index (RI) measured in the anterior cerebral artery on transfontanellar head ultrasound is a noninvasive measure of blood flow and may indicate autoregulation dysfunction. We tested whether RI was associated with brain injury on diffusion tensor imaging magnetic resonance imaging (MRI). Seventy-five neonates who underwent therapeutic hypothermia for HIE were enrolled. Resistive index values were obtained from head ultrasound performed at the end of therapeutic hypothermia. Apparent diffusion coefficient scalars were measured on MRIs performed before day of life 10. Lower RI was associated with lower apparent diffusion coefficient in the centrum semiovale, basal ganglia, thalamus, and posterior limb of the internal capsule. Combining RI and Apgar scores improved the ability to distinguish injury severity on MRI relative to either metric alone. Low RI correlated with worse brain injury on diffusion tensor imaging and may serve as an early marker of brain injury in cooled HIE neonates.

Utilizing Simulation to Identify Latent Safety Threats During Neonatal Magnetic Resonance Imaging Procedure.

Transfer of infants for magnetic resonance imaging (MRI) from the neonatal intensive care unit (NICU) requires exposure to unfamiliar environments and involve multiple complex human and system interactions, which can compromise patient safety. In situ simulation (ISS) offers an opportunity to identify latent safety threats (LSTs) that may occur during this high-risk procedure. Our primary aim was to use ISS to identify modifiable LSTs during the MRI procedure: involving neonatal transport to/from NICU to the MRI and the MRI scan. Secondarily, we compared the overall performance and needs of specialized versus nonspecialized transport personnel. In situ simulations of the MRI procedure (transport and scan) were performed for 9 months involving specialized and nonspecialized transport personnel. Two simulation scenarios were used, one involving an intubated infant and one nonintubated infant. After each simulation, participants underwent a standardized debriefing and answered questionnaires on safety threats and team function. The results were then used to identify and implement mitigation strategies. Among 10 simulations completed, 7 were by specialized and 3 by nonspecialized teams. In total, 116 LSTs were identified (22 involving medication, 12 equipment, and 82 resources/system issues). Preprocedure deliberation with anticipation/preparedness for patient deterioration, and the need for clinical checklists and protocols were identified as important requirements. After completion of the project, protocols (ie, sedation), checklists (ie, pretransport), and policies (ie, environmental orientation) were adapted to address the gaps. In situ simulations were able to identify important safety risks during transport of neonatal patients from the NICU to the MRI suite, informing changes in MRI transport policy.

Ultrasound and Magnetic Resonance Imaging of Agenesis of the Corpus Callosum in Fetuses

We hypothesized that: (1) fetal frontal horn (FH) morphology and their proximity to the cavum septi pellucidi (CSP) can assist in suspecting complete agenesis of the corpus callosum (cACC) and partial agenesis of the corpus callosum (pACC) earlier than known indirect ultrasound (US) findings; (2) FHs assist in differentiating a true CSP from a pseudocavum; and (3) magnetic resonance imaging (MRI) is useful in learning FH morphology and pseudocavum etiology. Thirty-two patients with cACC and 9 with pACC were identified on an Institutional Review Board-approved retrospective review. Of the 41 cases, 40 had prenatal US, and 21 had prenatal MRI; 17 had follow-up neonatal US, and 14 had follow-up neonatal MRI. Variables evaluated retrospectively were the presence of a CSP or a pseudocavum, ventricle size and shape, and FH shape (comma, trident, parallel, golf club, enlarged, or fused). Displacement between the inferior edge of the FH and the midline or cavum/pseudocavum was measured. Fetal FHs had an abnormal shape in 77% ≤20 weeks' gestation, 86% ≤24 weeks, and 90% >24 weeks. Frontal horns were laterally displaced greater than 2 mm in 85% ≤20 weeks, 91% ≤24 weeks, and 95% >24 weeks. The CSP was absent in 100% of cACC cases and 78% of pACC cases, and a pseudocavum was present in 88% of cACC cases and 78% of pACC cases across gestation. Magnetic resonance imaging confirmed US pseudocavums to be focal interhemispheric fluid or an elevated/dilated third ventricle. Frontal horns assist in assessing ACC ≤24 weeks and throughout gestation. Pseudocavums, often simulating CSPs, are common in ACC. Frontal horn lateral displacement and abnormal morphology, recognized by MRI correlations, are helpful in differentiating a pseudocavum from a true CSP. A normal CSP should not be cleared on screening US unless normally shaped FHs are seen directly adjacent to it.

Multi-atlas based neonatal brain extraction using atlas library clustering and local label fusion

Brain extraction is one of the most important preprocessing steps in cerebral magnetic resonance (MR) image analysis. Brain extraction from neonatal MR images is particularly challenging due to significant differences in head size and shape between neonates and rapid changes in neonatal brain structure in the weeks and months after birth. In this work, a multi-atlas-based neonatal brain extraction method using atlas library clustering and local label fusion (NOBELL) is presented. In NOBELL, an affinity propagation (AP) approach is first applied to cluster images of an atlas library into clusters represented by exemplars, which are used to select best matching clusters for target images. A local weighted voting strategy based on Jacobian determinant ranking is then employed to extract brain from target images using training images in best matching clusters. The performance of NOBELL was evaluated on T2- and T1-weighted scans of 40 neonates aged between 37 and 44 weeks. NOBELL outperformed two popular brain extraction tools, FSL’s Brain Extraction Tool (BET) and BrainSuite’s Brain Surface Extractor (BSE), and achieved higher accuracy with brain masks very close to manually extracted ones. NOBELL showed an average Jaccard coefficient of 0.974 (0.942) on T2 (T1)-weighted images in comparison with 0.908 (0.602) and 0.845 (0.762) achieved by BSE, and BET, respectively. NOBELL allows for accurate and efficient brain extraction, a crucial step in brain MRI applications such as accurate brain tissue segmentation and volume estimation as well as accurate cortical surface delineation in neonates.

Early alterations in cortical and cerebellar regional brain growth in Down Syndrome: An in vivo fetal and neonatal MRI assessment.

Down Syndrome (DS) is the most frequent genetic cause of intellectual disability with a wide spectrum of neurodevelopmental outcomes. At present, the relationship between structural brain morphology and the spectrum of cognitive phenotypes in DS, is not well understood. This study aimed to quantify the development of the fetal and neonatal brain in DS participants, with and without a congenital cardiac defect compared with a control population using dedicated, optimised and motion-corrected in vivo magnetic resonance imaging (MRI). We detected deviations in development and altered regional brain growth in the fetus with DS from 21 weeks' gestation, when compared to age-matched controls. Reduced cerebellar volume was apparent in the second trimester with significant alteration in cortical growth becoming evident during the third trimester. Developmental abnormalities in the cortex and cerebellum are likely substrates for later neurocognitive impairment, and ongoing studies will allow us to confirm the role of antenatal MRI as an early biomarker for subsequent cognitive ability in DS. In the era of rapidly developing technologies, we believe that the results of this study will assist counselling for prospective parents.