Comparison of computer tomography and magnetic resonance imaging scans on the third day of life in term newborns with neonatal encephalopathy

Comparative evaluation of approach to cardiovascular care in neonatal encephalopathy undergoing therapeutic hypothermia

OBJECTIVE

To analyze the association between cardiovascular care and adverse outcome in infants undergoing therapeutic hypothermia for neonatal encephalopathy (NE).

STUDY DESIGN

This was a retrospective cohort study of 176 infants with NE and hypotension, admitted to the SickKids Hospital (Center A, n = 86) or Semmelweis University (Center B, n = 90).

RESULT

The lowest systolic/diastolic blood pressures were comparable amongst centers; however, proportion of cardiovascular support was lower in Center A (51% vs 97% in Center B). Overall rate of death or abnormal MRI (adverse outcome) were comparable between centers, although pattern differed with more basal ganglia injury in Center B. A 24-hour longer duration of cardiovascular support increased the odds for adverse outcome by 14%.

CONCLUSION

We demonstrated that management of hemodynamic instability in infants with NE was markedly different in two high-volume NICUs and showed that longer duration of cardiovascular medication is an independent risk factor for adverse outcome.

An Updated Overview of MRI Injuries in Neonatal Encephalopathy: LyTONEPAL Cohort

BACKGROUND

Brain magnetic resonance imaging (MRI) is a key tool for the prognostication of encephalic newborns in the context of hypoxic-ischemic events. The purpose of this study was to finely characterize brain injuries in this context.

METHODS

We provided a complete, descriptive analysis of the brain MRIs of infants included in the French national, multicentric cohort LyTONEPAL.

RESULTS

Among 794 eligible infants, 520 (65.5%) with MRI before 12 days of life, grade II or III encephalopathy and gestational age ≥36 weeks were included. Half of the population had a brain injury (52.4%); MRIs were acquired before 6 days of life among 247 (47.5%) newborns. The basal ganglia (BGT), white matter (WM) and cortex were the three predominant sites of injuries, affecting 33.8% (n = 171), 33.5% (n = 166) and 25.6% (n = 128) of participants, respectively. The thalamus and the periventricular WM were the predominant sublocations. The BGT, posterior limb internal capsule, brainstem and cortical injuries appeared more frequently in the early MRI group than in the late MRI group.

CONCLUSION

This study described an overview of brain injuries in hypoxic-ischemic neonatal encephalopathy. The basal ganglia with the thalamus and the WM with periventricular sublocation injuries were predominant. Comprehensive identification of brain injuries in the context of HIE may provide insight into the mechanism and time of occurrence.

Neurodevelopmental outcome following hypoxic ischaemic encephalopathy and therapeutic hypothermia is related to right ventricular performance at 24-hour postnatal age

OBJECTIVE

Our aim was to determine whether right ventricular (RV) dysfunction at 24-hour postnatal age predicts adverse developmental outcome among patients with hypoxic ischaemic encephalopathy (HIE) undergoing therapeutic hypothermia (TH).

DESIGN

Neonates≥35 weeks with HIE/TH were enrolled in a physiological study in the neonatal period (n=46) and either died or underwent neurodevelopmental follow-up at 18 months (n=43). The primary outcome was a composite of death, diagnosis of cerebral palsy or any component of the Bayley Scores of Infant Development III<70. We hypothesised that tricuspid annulus plane systolic excursion (TAPSE) <6 mm and/or RV fractional area change (RV-FAC) <0.29 would predict adverse outcome.

RESULTS

Nine patients died and 34 patients were followed up at a mean age of 18.9±1.4 months. Both indices of RV systolic performance were abnormal in 15 (35%) patients, TAPSE <6 mm only was abnormal in 4 (9%) patients and RV-FAC <0.29 only was abnormal in 5 (12%) patients (19 had with normal RV function). Although similar at admission, neonates with RV dysfunction had higher cardiovascular and neurological illness severity by 24 hours than those without and severe MRI abnormalities (70% vs 53%, p=0.01) were more common. On logistic regression, TAPSE <6 mm (OR 3.6, 95% CI 1.2 to 10.1; p=0.017) and abnormal brain MRI [OR 21.7, 95% CI 1.4 to 336; p=0.028) were independently associated with adverse outcome. TAPSE <6 mm predicted outcome with a 91% sensitivity and 81% specificity.

CONCLUSIONS

The role of postnatal cardiovascular function on neurological outcomes among patients with HIE who receive TH merits further study. Quantitative measurement of RV function at 24 hours may provide an additional neurological prognostic tool.

Restricted diffusion in the corpus callosum: A neuroradiological marker in hypoxic-ischemic encephalopathy

Background:

Restricted diffusion within the splenium of the corpus callosum has been described by other authors in various conditions, however, restricted diffusion in the entire corpus callosum or isolated involvement of the splenium, genu, or body has been infrequently reported on magnetic resonance imaging (MRI) in neonatal hypoxic–ischemic encephalopathy. We report a series of cases showing different patterns of involvement.

Methods and Materials:

Perinatal imaging with MRI including diffusion-weighted imaging was performed in 40 neonates with hypoxic–ischemic encephalopathy, including 11 premature neonates. Sixteen out of 40 patients demonstrated restricted diffusion within the corpus callosum. Out of 16 patients, 9 showed restricted diffusion in the entire corpus callosum, 4 had isolated splenium involvement, 2 had body and splenium signal abnormality, and 1 showed diffusion restriction only in the genu.

Conclusions:

Changes in the corpus callosum were also associated with more severe clinical presentation of encephalopathy. Restricted diffusion within the corpus callosum in infants with hypoxic–ischemic encephalopathy is often associated with extensive brain injury and appears to be an early neuroradiologic marker of adverse neurologic outcome.

Neuroimaging at Term Equivalent Age: Is There Value for the Preterm Infant? A Narrative Summary

Advances in neuroimaging of the preterm infant have enhanced the ability to detect brain injury. This added information has been a blessing and a curse. Neuroimaging, particularly with magnetic resonance imaging, has provided greater insight into the patterns of injury and specific vulnerabilities. It has also provided a better understanding of the microscopic and functional impacts of subtle and significant injuries. While the ability to detect injury is important and irresistible, the evidence for how these injuries link to specific long-term outcomes is less clear. In addition, the impact on parents can be profound. This narrative summary will review the history and current state of brain imaging, focusing on magnetic resonance imaging in the preterm population and the current state of the evidence for how these patterns relate to long-term outcomes.

Impaired Right Ventricular Performance Is Associated with Adverse Outcome after Hypoxic Ischemic Encephalopathy

Rationale: Asphyxiated neonates with hypoxic ischemic encephalopathy (HIE) are at risk of myocardial dysfunction; however, echocardiography studies are limited and little is known about the relationship between hemodynamics and brain injury.Objectives: To analyze the association between severity of myocardial dysfunction and adverse outcome as defined by the composite of death and/or abnormal magnetic resonance imaging.Methods: Neonates with HIE undergoing therapeutic hypothermia were enrolled. Participants underwent echocardiography at 24 hours, 72 hours (before rewarming), and 96 hours (after rewarming). Cerebral hemodynamics were monitored by near-infrared spectroscopy and middle cerebral artery Doppler.Measurements and Main Results: Fifty-three patients with a mean gestation and birthweight of 38.8 ± 2.0 weeks and 3.33 ± 0.6 kg, respectively, were recruited. Thirteen patients (25%) had mild encephalopathy, 27 (50%) had moderate encephalopathy, and 13 (25%) had severe encephalopathy. Eighteen patients (34%) had an adverse outcome. Severity of cardiovascular illness (P < 0.001) and severity of neurologic insult (P = 0.02) were higher in neonates with adverse outcome. Right ventricle (RV) systolic performance at 24 hours was substantially lower than published normative data in all groups. At 24 hours, lower tricuspid annular plane systolic excursion (P = 0.004) and RV fractional area change (P < 0.001), but not pulmonary hypertension, were independently associated with adverse outcome on logistic regression. High brain regional oxygen saturation (P = 0.007) and low middle cerebral artery resistive index (P = 0.04) were associated with RV dysfunction on post hoc analysis.Conclusions: RV dysfunction is associated with the risk of adverse outcome in asphyxiated patients with HIE undergoing hypothermia. Echocardiography may be a valuable diagnostic and prognostic tool in this vulnerable population.

Neurodevelopmental outcomes of children with congenital heart disease: A review

Congenital heart defects are the most common birth anomaly affecting approximately 1% of births. With improved survival in this population, there is enhanced ability to assess long-term morbidities including neurodevelopment. There is a wide range of congenital heart defects, from those with minimal physiologic consequence that do not require medical or surgical intervention, to complex structural anomalies requiring highly specialized medical management and intricate surgical repair or palliation. The impact of congenital heart disease on neurodevelopment is multifactorial. Susceptibility for adverse neurodevelopment increases with advancing severity of the defect with initial risk factors originating during gestation. Complex structural heart anomalies may pre-dispose the fetus to abnormal circulatory patterns in utero that ultimately impact delivery of oxygen rich blood to the fetal brain. Thus, the brain of a neonate born with complex congenital heart disease may be particularly vulnerable from the outset. That vulnerability is compounded during the newborn period and through childhood, as this population endures a myriad of medical and surgical interventions. For each individual patient, these factors are likely cumulative and synergistic with progression from fetal life through childhood. This review discusses the spectrum of risk factors that may impact neurodevelopment in children with congenital heart disease, describes current recommendations and practices for neurodevelopmental follow-up of children with congenital heart disease and reviews important neurodevelopmental trends in this high risk population.

[Clinical value of serum neuroglobin in evaluating hypoglycemic brain injury in neonates]

OBJECTIVE

To study the clinical value of serum neuroglobin in evaluating hypoglycemic brain injury in neonates.

METHODS

A total of 100 neonates with hypoglycemia were enrolled as subjects. According to amplitude-integrated EEG (aEEG) findings and/or clinical manifestations, they were divided into symptomatic hypoglycemic brain injury group (n=22), asymptomatic hypoglycemic brain injury group (n=37) and hypoglycemic non-brain injury group (n=41). The three groups were compared in terms of blood glucose, duration of hypoglycemia, levels of neuroglobin and neuron-specific enolase (NSE), and modified aEEG score. The correlation of neuroglobin with NSE and modified aEEG score was analyzed. The receiver operating characteristic (ROC) curve was plotted.

RESULTS

Compared with the asymptomatic hypoglycemic brain injury and hypoglycemic non-brain injury groups, the symptomatic hypoglycemic brain injury group had significantly lower blood glucose and modified aEEG score, significantly higher neuroglobin and NSE levels, and a significantly longer duration of hypoglycemia (P<0.05). Compared with the hypoglycemic non-brain injury group, the asymptomatic hypoglycemic brain injury group had significantly lower blood glucose and modified aEEG score, significantly higher neuroglobin and NSE levels, and a significantly longer duration of hypoglycemia (P<0.05). Neuroglobin was positively correlated with NSE and duration of hypoglycemia (r=0.922 and 0.929 respectively; P<0.05) and negatively correlated with blood glucose and modified aEEG score (r=-0.849 and -0.968 respectively; P<0.05). The areas under the ROC curve of neuroglobin, NSE and modified aEEG score were 0.894, 0.890 and 0.941 respectively, and neuroglobin had a sensitivity of 80.8% and a specificity of 95.8% at the optimal cut-off value of 108 mg/L.

CONCLUSIONS

Like NSE and modified aEEG score, serum neuroglobin can also be used as a specific indicator for the assessment of brain injury in neonates with hypoglycemia and has a certain value in clinical practice.

Pattern of Brain Injury Predicts Long-Term Epilepsy Following Neonatal Encephalopathy

OBJECTIVE

To determine if patterns of hypoxic-ischemic brain injury on magnetic resonance imaging (MRI) in term newborns predict subsequent childhood epilepsy.

METHODS

This retrospective cohort study includes term newborns with encephalopathy (n = 181) born between 2004-2012 and admitted to British Columbia Children's Hospital. MRI was performed between 3 and 5 days of age. The predominant patterns of hypoxic-ischemic injury were classified as Normal, Watershed, Basal Nuclei, Total, and Focal-Multifocal. Lesions in hippocampus, motor and occipital cortex were noted.

RESULTS

Of 181 newborns, 166 (92%) survived the neonatal period, and 132 (80%) had follow-up with a median duration of 61 months (IQR: 28-95). Twenty-three children (17%) developed epilepsy. A higher proportion with Watershed, Basal Nuclei, or Total patterns developed epilepsy (P < .001). Injury to motor cortex, hippocampus, and occipital lobe (P < .01) were independent risk factors for epilepsy. In the adjusting logistic model, Watershed (odds ratio = 16.0, 95% CI [1.3, 197.2], P = .03) and Basal Nuclei injury (odds ratio = 19.4, 95% CI [1.9, 196.3], P = .01) remained independent risk factors. Therapeutic hypothermia did not alter these associations. Severity of brain injury and recurrent neonatal seizures are other clinical risk factors.

SIGNIFICANCE

In term newborns with hypoxic-ischemic encephalopathy, the predominant pattern of Watershed and Basal Nuclei injury are valuable predictors for development of epilepsy in later childhood.

Imaging the term neonatal brain

Brain imaging is important for the diagnosis and management of sick term neonates. Although ultrasound and computed tomography may provide some information, magnetic resonance imaging is now the brain imaging modality of choice because it is the most sensitive technique for detecting and quantifying brain abnormalities and does not expose infants to radiation. This statement describes the principles, roles and limitations of these three imaging modalities and makes recommendations for appropriate use in term neonates. The primary focus is the brain of term infants with neonatal encephalopathy, many of whom are diagnosed with hypoxic-ischemic encephalopathy.

MRI Changes in the Thalamus and Basal Ganglia of Full-Term Neonates with Perinatal Asphyxia

BACKGROUND

Magnetic resonance imaging (MRI) is the standard neuroimaging technique to assess perinatal asphyxia-associated brain injury in full-term infants. Diffusion-weighted imaging (DWI) is most informative when assessed during the first week after the insult.

OBJECTIVES

To study the DWI abnormalities of the thalamus and basal ganglia in full-term infants with perinatal asphyxia.

METHODS

Fifty-five (near) term infants (normothermia n = 23; hypothermia n = 32) with thalamus and/or basal ganglia injury were included. MRI findings were assessed visually and quantitatively calculating apparent diffusion coefficient (ADC) values. Thalamus/basal ganglia ADC ratios were calculated to analyze the differences between these areas. Infants with an early MRI (days 1-3) or later MRI (days 4-7) were compared.

RESULTS

Isolated extensive thalamic injury was seen early, and focal thalamic and basal ganglia injury was seen later. On the early MRI, visual assessment underestimated abnormalities in the basal ganglia (59% abnormal vs. 90% abnormal on quantitative assessment; p = 0.015), suggesting the need for quantitative assessment. In infants treated with hypothermia, the thalamus/basal ganglia ADC ratio was lower.

CONCLUSIONS

Both visual analysis and quantitative evaluation of cerebral MRI after perinatal asphyxia are needed, especially during the first few days after birth. Timing of ADC changes is influenced by therapeutic hypothermia.

[Patterns of brain injury in neonatal hypoxic-ischemic encephalopathy on magnetic resonance imaging: recommendations on classification]

Although there are unified criteria for the clinical diagnosis and grading of neonatal hypoxic-ischemic encephalopathy (HIE), clinical features and neuropathological patterns vary considerably among the neonates with HIE due to birth asphyxia in the same classification. The patterns and progression of brain injury in HIE, which is closely associated with long-term neurodevelopment outcomes, can be well shown on magnetic resonance imaging (MRI), but different sequences may lead to different MRI findings at the same time. It is suggested that diffusion-weighted imaging sequence be selected at 2-4 days after birth, and the conventional MRI sequence at 4-8 days. The major patterns of brain injury in HIE on MRI are as follows: injury of the thalamus and basal ganglia and posterior limbs of the internal capsules; watershed injury involving the cortical and subcortical white matter; focal or multifocal minimal white matter injury; extensive whole brain injury. Severe acute birth asphyxia often leads to deep grey matter injury (thalamus and basal ganglia), and the brain stem may also be involved; the pyramidal tract is the most susceptible white matter fiber tract; repetitive or intermittent hypoxic-ischemic insults, with inflammation or hypoglycemia, usually cause injuries in the watershed area and deep white matter. It is worth noting that sometimes the pattern of brain injury among those described above cannot be determined exactly, but rather a predominant one is identified; not all cases of HIE have characteristic MRI findings.

[Recommendations for imaging neonatal ischemic stroke]

Neuroimaging is critical for the diagnosis of neonatal arterial ischemic stroke (NAIS) and for prognosis estimation. The purpose of this work is to define guidelines of clinical neuroimaging for the diagnosis of NAIS, for the optimization of the imaging timing and for the assessment of the prognostic value of each imaging technique. A systematic search of electronic databases (Medline via Pubmed) for studies whose title and abstract were focused on NAIS has been conducted. One hundred and ten articles were selected and their results were analyzed by three Senior Practitioners of pediatric radiology using common methodology for guidelines elaboration within the group of experts gathered by Scientific Societies in the field. MRI with a diffu si on-weighted sequence (DWI) and T1, T2, and T2*-weighted sequences must be performed in the case of suspected NAIS (no sedation is required). In the first hours after the injury, an acute ischemic lesion is characterized by a hypersignal on the diffusion-weighted sequence, with a decrease of the apparent coefficient of diffusion (ADC). The best time to evaluate the extent of the ischemic lesion is between day 2 and day 4 after injury, when the ADC decrease reaches its nadir. In the acute phase, US may be useful as first imaging at the bedside to exclude other pathologies like large space-occupying hemorrhages, but its specific added value on NAIS diagnosis or prognosis assessment is very low. CT scan has no added value in NAIS, compared to MRI. Motor outcome is correlated with the extent of the lesion and with the presence of a definite injury of the corticospinal tract, which is well seen on the diffusion sequence at the acute stage. A secondary atrophy within the mesencephalon (cerebral peduncles) is tied in with a high risk of hemiplegia. Visual outcome is more often compromised in the case of lesions of the posterior cerebral artery territory.

Neonatal Hypoxia Ischaemia: Mechanisms, Models, and Therapeutic Challenges

Neonatal hypoxia-ischaemia (HI) is the most common cause of death and disability in human neonates, and is often associated with persistent motor, sensory, and cognitive impairment. Improved intensive care technology has increased survival without preventing neurological disorder, increasing morbidity throughout the adult population. Early preventative or neuroprotective interventions have the potential to rescue brain development in neonates, yet only one therapeutic intervention is currently licensed for use in developed countries. Recent investigations of the transient cortical layer known as subplate, especially regarding subplate's secretory role, opens up a novel set of potential molecular modulators of neonatal HI injury. This review examines the biological mechanisms of human neonatal HI, discusses evidence for the relevance of subplate-secreted molecules to this condition, and evaluates available animal models. Neuroserpin, a neuronally released neuroprotective factor, is discussed as a case study for developing new potential pharmacological interventions for use post-ischaemic injury.

Fifty years of brain imaging in neonatal encephalopathy following perinatal asphyxia

In the past brain imaging of term infants with hypoxic-ischemic encephalopathy (HIE) was performed with cranial ultrasound (cUS) and computed tomography (CT). Both techniques have several disadvantages sensitivity and specificity is limited compared with magnetic resonance imaging (MRI) and CT makes use of radiation. At present MRI including diffusion weighted MRI during the first week of life, has become the method of choice for imaging infants with HIE. In addition to imaging, blood vessels and blood flow can be visualized using MR angiography, MR venography, and arterial spin labeling. Since the use of these techniques additional lesions in infants with HIE, such as arterial ischemic stroke, sinovenous thrombosis, and subdural hemorrhages can be diagnosed, and the incidence appears to be higher than shown previously. Phosphorus magnetic resonance spectroscopy (MRS) has led to the concept of secondary energy failure in infants with HIE, but has not been widely used. Proton MRS of the basal ganglia and thalamus is one of the best predictors of neurodevelopmental outcome. cUS should still be used for screening infants admitted to a NICU with neonatal encephalopathy. In the future magnetic resonance techniques will be increasingly used as early biomarkers of neurodevelopmental outcome in trials of neuroprotective strategies.

Low plasma magnesium is associated with impaired brain metabolism in neonates with hypoxic-ischaemic encephalopathy

AIM

To determine the association between lowest plasma magnesium concentration and brain metabolism, and whether magnetic resonance imaging brain injury patterns moderated the association in hypoxic-ischemic encephalopathy.

METHODS

In 131 early (day-of-life 3) and 65 late (day-of-life 10) scans of term encephalopathic infants born between 2004 and 2012, we examined the association of lowest plasma magnesium (until day-of-life 3) on basal ganglia and white matter peak metabolite ratios on magnetic resonance spectroscopy independent of covariates, stratified by the predominant patterns of injury (normal, basal nuclei/total, watershed, multifocal) using multiple linear regression.

RESULTS

Lowest plasma magnesium was associated with lower white matter N-acetyl-aspartate/choline in the multifocal pattern on early scan (regression-coefficient, β: 0.13; 95% CI: 0.04, 0.22) and in the basal nuclei/total pattern on late scan (β: 0.08; 95% CI: 0.02, 0.15), and was negatively associated with basal ganglia lactate/N-acetyl-aspartate (β: -0.16; 95% CI: -0.05, -0.28) and lactate/choline (β: -0.1; 95% CI: -0.03, -0.17) ratio in the basal nuclei/total pattern on late scan independent of hypomagnesaemia correction, cooling and postmenstrual age at scan. Lowest plasma magnesium was not associated with metabolite ratios in other brain injury patterns.

CONCLUSION

In infants with hypoxic-ischaemic encephalopathy, predominant patterns of brain injury moderated the association between lowest plasma magnesium in the first three days of life and impaired brain metabolism.

Neuroimaging and Other Neurodiagnostic Tests in Neonatal Encephalopathy

Hypoxic-ischemic encephalopathy is associated with a high risk of morbidity and mortality in the neonatal period. Long-term neurodevelopmental disability is also frequent in survivors. Conventional MRI defines typical patterns of injury that reflect specific pathophysiologic mechanisms. Advanced magnetic resonance techniques now provide unique perspectives on neonatal brain metabolism, microstructure, and connectivity. The application of these imaging techniques has revealed that brain injury commonly occurs at or near the time of birth and evolves over the first weeks of life. Amplitude-integrated electroencephalogram and near-infrared spectroscopy are increasingly used as bedside tools in neonatal intensive care units to monitor brain function.

Pathogenesis, neuroimaging and management in children with cerebral palsy born preterm

With advances in obstetric and perinatal management, the incidence of intraventricular hemorrhage in premature infants has declined, while periventricular leukomalacia remains a significant concern. It is now known that brain injury in children born preterm also involves neuronal-axonal disease in supratentorial and infratentorial structures. The developing brain is especially vulnerable to white matter (WM) injury from 23 to 34 weeks gestation when blood vessels serving the periventricular WM are immature. Oligodendrocyte progenitors, which are beginning to form myelin during this time, are susceptible to attack from oxygen free radicals, glutamate, and inflammatory cytokines. Advances in imaging techniques such as diffusion tensor imaging provide a more complete picture of the location and extent of injury. Effective management of children born preterm with cerebral palsy is predicated on an understanding of sequential links from etiological antecedents to brain neuropathology as revealed with neuroimaging techniques to clinical phenotypes, toward focused interventions with measurable outcomes.

Initial Application of Diffusional Kurtosis Imaging in Evaluating Brain Development of Healthy Preterm Infants

Objective

To explore the parametric characteristics of diffusional kurtosis imaging (DKI) in the brain development of healthy preterm infants.

Materials and Methods

Conventional magnetic resonance imaging (MRI) and DKI were performed in 35 preterm (29 to 36 weeks gestational age [GA]; scanned at 33 to 44 weeks postmenstrual age [PMA]) and 10 term infants (37.4 to 40.7 weeks GA; scanned at 38.3 to 42.9 weeks PMA). Fractional anisotropy (FA), mean diffusivity (MD) and mean kurtosis (MK) values from 8 regions of interest, including both white matter (WM) and gray matter (GM), were obtained.

Results

MK and FA values were positively correlated with PMA in most selected WM regions, such as the posterior limbs of the internal capsule (PLIC) and the splenium of the corpus callosum (SCC). The positive correlation between MK value and PMA in the deep GM region was higher than that between FA and PMA. The MK value gradually decreased from the PLIC to the cerebral lobe. In addition, DKI parameters exhibited subtle differences in the parietal WM between the preterm and term control groups.

Conclusions

MK may serve as a more reliable imaging marker of the normal myelination process and provide a more robust characterization of deep GM maturation.

Reliability of Early Magnetic Resonance Imaging (MRI) and Necessity of Repeating MRI in Noncooled and Cooled Infants With Neonatal Encephalopathy

In cooled newborns with encephalopathy, although late magnetic resonance imaging (MRI) scan (10-14 days of age) is reliable in predicting long-term outcome, it is unknown whether early scan (3-6 days of life) is. We compared the predominant pattern and extent of lesion between early and late MRI in 89 term neonates with neonatal encephalopathy. Forty-three neonates (48%) were cooled. The predominant pattern of lesions and the extent of lesion in the watershed region agreed near perfectly in noncooled (kappa = 0.94; k = 0.88) and cooled (k = 0.89; k = 0.87) infants respectively. There was perfect agreement in the extent of lesion in the basal nuclei in noncooled infants (k = 0.83) and excellent agreement in cooled infants (k = 0.67). Changes in extent of lesions on late MRI occurred in 19 of 89 infants, with higher risk in infants with hypoglycemia and moderate-severe lesions in basal nuclei. In most term neonates with neonatal encephalopathy, early MRI (relative to late scan) robustly predicts the predominant pattern and extent of injury.

Preferential cephalic redistribution of left ventricular cardiac output during therapeutic hypothermia for perinatal hypoxic-ischemic encephalopathy

OBJECTIVE

To determine the relationship between left ventricular cardiac output (LVCO), superior vena cava (SVC) flow, and brain injury during whole-body therapeutic hypothermia.

STUDY DESIGN

Sixteen newborns with moderate or severe hypoxic-ischemic encephalopathy were studied using echocardiography during and immediately after therapeutic hypothermia. Measures were also compared with 12 healthy newborns of similar postnatal age. Newborns undergoing therapeutic hypothermia also had cerebral magnetic resonance imaging as part of routine clinical care on postnatal day 3-4.

RESULTS

LVCO was markedly reduced (mean ± SD 126 ± 38 mL/kg/min) during therapeutic hypothermia, whereas SVC flow was maintained within expected normal values (88 ± 27 mL/kg/min) such that SVC flow represented 70% of the LVCO. The reduction in LVCO during therapeutic hypothermia was mainly accounted by a reduction in heart rate (99 ± 13 vs 123 ± 17 beats/min; P < .001) compared with immediately postwarming in the context of myocardial dysfunction. Neonates with brain injury on magnetic resonance imaging had higher SVC flow prerewarming, compared with newborns without brain injury (P = .013).

CONCLUSION

Newborns with perinatal hypoxic-ischemic encephalopathy showed a preferential systemic-to-cerebral redistribution of cardiac blood flow during whole-body therapeutic hypothermia, which may reflect a lack of cerebral vascular adaptation in newborns with more severe brain injury.

Regional brain injury on conventional and diffusion weighted MRI is associated with outcome after pediatric cardiac arrest

BACKGROUND

To assess regional brain injury on magnetic resonance imaging (MRI) after pediatric cardiac arrest (CA) and to associate regional injury with patient outcome and effects of hypothermia therapy for neuroprotection.

METHODS

We performed a retrospective chart review with prospective imaging analysis. Children between 1 week and 17 years of age who had a brain MRI in the first 2 weeks after CA without other acute brain injury between 2002 and 2008 were included. Brain MRI (1.5 T General Electric, Milwaukee, WI, USA) images were analyzed by 2 blinded neuroradiologists with adjudication; images were visually graded. Brain lobes, basal ganglia, thalamus, brain stem, and cerebellum were analyzed using T1, T2, and diffusion-weighted images (DWI).

RESULTS

We examined 28 subjects with median age 1.9 years (IQR 0.4-13.0) and 19 (68 %) males. Increased intensity on T2 in the basal ganglia and restricted diffusion in the brain lobes were associated with unfavorable outcome (all P < 0.05). Therapeutic hypothermia had no effect on regional brain injury. Repeat brain MRI was infrequently performed but demonstrated evolution of lesions.

CONCLUSION

Children with lesions in the basal ganglia on conventional MRI and brain lobes on DWI within the first 2 weeks after CA represent a group with increased risk of poor outcome. These findings may be important for developing neuroprotective strategies based on regional brain injury and for evaluating response to therapy in interventional clinical trials.

Na⁺/H⁺ exchangers and intracellular pH in perinatal brain injury

Encephalopathy consequent on perinatal hypoxia–ischemia occurs in 1–3 per 1,000 term births in the UK and frequently leads to serious and tragic consequences that devastate lives and families, with huge financial burdens for society. Although the recent introduction of cooling represents a significant advance, only 40 % survive with normal neurodevelopmental function. There is thus a significant unmet need for novel, safe, and effective therapies to optimize brain protection following brain injury around birth. The Na⁺/H⁺ exchanger (NHE) is a membrane protein present in many mammalian cell types. It is involved in regulating intracellular pH and cell volume. NHE1 is the most abundant isoform in the central nervous system and plays a role in cerebral damage after hypoxia–ischemia. Excessive NHE activation during hypoxia–ischemia leads to intracellular Na⁺ overload, which subsequently promotes Ca²⁺ entry via reversal of the Na⁺/Ca²⁺ exchanger. Increased cytosolic Ca²⁺ then triggers the neurotoxic cascade. Activation of NHE also leads to rapid normalization of pH_i and an alkaline shift in pH_i. This rapid recovery of brain intracellular pH has been termed pH paradox as, rather than causing cells to recover, this rapid return to normal and overshoot to alkaline values is deleterious to cell survival. Brain pH_i changes are closely involved in the control of cell death after injury: an alkalosis enhances excitability while a mild acidosis has the opposite effect. We have observed a brain alkalosis in 78 babies with neonatal encephalopathy serially studied using phosphorus-31 magnetic resonance spectroscopy during the first year after birth (151 studies throughout the year including 56 studies of 50 infants during the first 2 weeks after birth). An alkaline brain pH_i was associated with severely impaired outcome; the degree of brain alkalosis was related to the severity of brain injury on MRI and brain lactate concentration; and a persistence of an alkaline brain pH_i was associated with cerebral atrophy on MRI. Experimental animal models of hypoxia–ischemia show that NHE inhibitors are neuroprotective. Here, we review the published data on brain pH_i in neonatal encephalopathy and the experimental studies of NHE inhibition and neuroprotection following hypoxia–ischemia.

MRI findings in infants with infantile spasms after neonatal hypoxic-ischemic encephalopathy

BACKGROUND

To evaluate the predominant pattern of brain injury and the anatomic areas of injury in children with infantile spasms following neonatal hypoxic-ischemic encephalopathy.

METHODS

A nested case-control study of infantile spasms in children with term neonatal hypoxic-ischemic encephalopathy was performed. All patients had T1/T2-weighted magnetic resonance imaging with diffusion-weighted imaging performed on the third day of life. Using a validated scoring system, the magnetic resonance imaging was classified as: normal, watershed, basal ganglia/thalamus, total, or focal-multifocal. Two study investigators scored additional anatomic areas of injury (cortical extent, levels of the brainstem, hypothalamus) on T1/T2-weighted magnetic resonance imaging and diffusion-weighted imaging blinded to the outcome. The predominant pattern of brain injury and anatomic areas of injury were compared between patients who developed infantile spasms and randomly selected controls.

RESULTS

Eight patients who developed infantile spasms were identified among a cohort of 176 term newborns with hypoxic-ischemic encephalopathy (4.5%). There were no significant differences in the perinatal and neonatal course between newborns who developed infantile spasms and controls who did not. The development of infantile spasms after neonatal hypoxic-ischemic encephalopathy was significantly associated with basal ganglia/thalamus and total brain injury (P = 0.001), extent of cortical injury greater than 50% (odds ratio = 11.7, 95% confidence interval = 1.1-158.5, P = 0.01), injury to the midbrain (odds ratio = 13, 95% confidence interval = 1.3-172, P = 0.007) and hypothalamic abnormalities (P = 0.01).

CONCLUSIONS

The development of infantile spasms after hypoxic-ischemic encephalopathy is associated with injury to the basal ganglia and thalami on neonatal magnetic resonance imaging, particularly when extensive cortical injury and/or injury to the midbrain is present.

Evolution of pattern of injury and quantitative MRI on days 1 and 3 in term newborns with hypoxic-ischemic encephalopathy

BACKGROUND

Brain injury in term neonatal hypoxic-ischemic encephalopathy (HIE) emerges on magnetic resonance imaging (MRI) by day 3. This study aimed to address the relationship of MRI, diffusion tensor imaging (DTI), and MR spectroscopic imaging (MRSI) findings on days 1 and 3 in a prospective cohort of term newborns with HIE.

METHODS

A total of 24 term newborns with HIE were prospectively studied with MRI on days 1 and 3; 19 were imaged with DTI and MRSI on days 1 and 3. MRI was assessed using validated scores. The relationship between MRI, DTI, and MRSI values on days 1 and 3 was determined using linear regression for repeated measures.

RESULTS

Conventional MRI showed a complex variation of findings from day 1 to 3. In gray matter, mean diffusivity (Dav) and metabolite ratios measured on day 1 were predictive of values on day 3 (all P ≤ 0.04). In white matter, Dav, fractional anisotropy (FA), and N-acetylaspartate (NAA)/choline on days 1 and 3 were strongly related (all P ≤ 0.003). Hypothermia appeared to attenuate the severity and progression of brain injury in the six treated newborns.

CONCLUSION

In term newborns with HIE, quantitative MR values on days 1 and 3 are strongly associated, providing an objective measure of injury before qualitative images.

Diffusion-weighted imaging changes in cerebral watershed distribution following neonatal encephalopathy are not invariably associated with an adverse outcome

AIM

Patterns of injury in term-born infants with neonatal encephalopathy following hypoxia-ischaemia are seen earlier and are more conspicuous on diffusion-weighted magnetic resonance imaging (DW-MRI) than on conventional imaging. Although the prognostic value of DW-MRI in infants with basal ganglia and thalamic damage has been established, data in infants in whom there is extensive injury in a watershed distribution are limited. The aim of this study was to assess cognitive and functional motor outcome in a cohort of infants with changes in a predominantly watershed distribution injury on neonatal cerebral MRI, including DWI.

METHOD

DW-MRI findings in infants with neonatal encephalopathy following hypoxia-ischaemia were evaluated retrospectively. Twenty-two infants in whom DWI changes exhibited a predominantly watershed distribution were enrolled in the study (10 males, 12 females; mean birthweight 3337 g, 2830-3900 g; mean gestational age 40.5 wks, 37.9-42.1 wks). Follow-up MRI data at the age of 3 months (n=15) and over the age of 18 months (n=7) were analysed. In survivors, neurodevelopmental outcome was assessed with the Griffiths Mental Development Scales at the age of at least 18 months. Amplitude-integrated electroencephalography was used to score background patterns and the occurrence of epileptiform activity.

RESULTS

DW-MRI revealed abnormalities that were bilateral in all infants and symmetrical in 10. The posterior regions were more severely affected in five infants and the anterior regions in three. Watershed injury occurred in isolation in 10 out of 22 infants and was associated with involvement of the basal ganglia and thalami in the other 12, of whom seven died. Cystic evolution, seen on MRI at age 3 months, occurred in three of the 15 surviving infants. Neurodevelopmental assessment of the surviving infants was performed at a median age of 35 months (range 18-48 mo). Of the five survivors with basal ganglia and thalamic involvement, two developed cerebral palsy, one had a developmental quotient of less than 85, and two had a normal outcome. Of the 10 infants with isolated watershed injury, nine had an early normal motor and cognitive outcome. In all infants with a favourable outcome, background recovery was seen on amplitude integrated EEG within 48 hours after birth.

CONCLUSION

Extensive DWI changes in a watershed distribution in term-born neonates are not invariably associated with adverse sequelae, even in the presence of cystic evolution. Associated lesions of the basal ganglia and thalami are a better predictor of adverse sequelae than the extent and severity of the watershed abnormalities seen on DW-MRI.

Brain injury patterns in hypoglycemia in neonatal encephalopathy

BACKGROUND AND PURPOSE

Low glucose values are often seen in term infants with NE, including HIE, yet the contribution of hypoglycemia to the pattern of neurologic injury remains unclear. We hypothesized that MR features of neonatal hypoglycemia could be detected, superimposed on the predominant HIE injury pattern.

MATERIALS AND METHODS

Term neonates (n = 179) with NE were prospectively imaged with day-3 MR studies and had glucose data available for review. The predominant imaging pattern of HIE was recorded as watershed, basal ganglia, total, focal-multifocal, or no injury. Radiologic hypoglycemia was diagnosed on the basis of selective edema in the posterior white matter, pulvinar, and anterior medial thalamic nuclei. Clinical charts were reviewed for evidence of NE, HIE, and hypoglycemia (<46 mg/dL).

RESULTS

The predominant pattern of HIE injury imaged included 17 watershed, 25 basal ganglia, 10 total, 42 focal-multifocal, and 85 cases of no injury. A radiologic diagnosis of hypoglycemia was made in 34 cases. Compared with laboratory-confirmed hypoglycemia, MR findings had a positive predictive value of 82% and negative predictive value of 78%. Sixty (34%) neonates had clinical hypoglycemia before MR imaging. Adjusting for 5-minute Apgar scores and umbilical artery pH with logistic regression, clinical hypoglycemia was associated with a 17.6-fold higher odds of MR imaging identification (P < .001). Selective posterior white matter and pulvinar edema were most predictive of clinical hypoglycemia, and no injury (36%) or a watershed (32%) pattern of injury was seen more often in severe hypoglycemia.

CONCLUSIONS

In term infants with NE and hypoglycemia, specific imaging features for both hypoglycemia and hypoxia-ischemia can be identified.

Neonatal encephalopathy: an inadequate term for hypoxic-ischemic encephalopathy

This Point of View article addresses neonatal encephalopathy (NE) presumably caused by hypoxia-ischemia and the terminology currently in wide use for this disorder. The nonspecific term NE is commonly utilized for those infants with the clinical and imaging characteristics of neonatal hypoxic-ischemic encephalopathy (HIE). Multiple magnetic resonance imaging studies of term infants with the clinical setting of presumed hypoxia-ischemia near the time of delivery have delineated a topography of lesions highly correlated with that defined by human neuropathology and by animal models, including primate models, of hypoxia-ischemia. These imaging findings, coupled with clinical features consistent with perinatal hypoxic-ischemic insult(s), warrant the specific designation of neonatal HIE.

Neonatal ischemic brain injury: what every radiologist needs to know

We present a pictorial review of neonatal ischemic brain injury and look at its pathophysiology, imaging features and differential diagnoses from a radiologist's perspective. The concept of perinatal stroke is defined and its distinction from hypoxic-ischemic injury is emphasized. A brief review of recent imaging advances is included and a diagnostic approach to neonatal ischemic brain injury is suggested.

An MR-compatible neonatal incubator

OBJECTIVES

To develop a neonatal MR-compatible incubator for transporting babies between a neonatal intensive care unit and an MRI unit that is within the same hospital but geographically separate.

METHODS

The system was strapped to a standard MR-compatible patient trolley, which provides space for resuscitation outside the incubator. A constant-temperature exothermic heat pad was used to maintain temperature together with a logging fluoro-optic temperature monitor and alarm system. The system has been designed to accommodate standard knee-sized coils from the major MR manufacturers. The original incubator was constructed from carbon fibre, but this required modification to prevent radiofrequency shading artefacts due to the conducting properties of the carbon fibre. A high-tensile polyester material was used, which combined light weight with high impact strength. The system could be moved onto the patient bed with the coils and infant in place by one technologist.

RESULTS

Studies in eight neonatal patients produced high quality 1.5 T MR images with low motion artefacts. The incubator should also be compatible with imaging in 3 T MR systems, although further work is required to establish this. Images were acquired using both rapid and high-resolution sequences, including three-dimensional volumes, proton spectra and diffusion weighting.

CONCLUSION

The incubator provides a safe, quiet environment for neonates during transport and imaging, at low cost.

Hypoxic-ischemic injury: utility of susceptibility-weighted imaging

Magnetic resonance imaging is increasingly used to assess neonatal hypoxic-ischemic injury, and several scoring systems were developed to predict neurologic outcomes in these patients. We examined the magnetic resonance imaging studies of 33 neonates/infants who manifested acute perinatal hypoxic-ischemic injuries. Using a seven-point susceptibility-weighted imaging categorical grading scale, each patient received a "prominence of vein" score, which was dichotomized into a "normal" or "abnormal" group. Six-month outcomes were assessed using the Pediatric Cerebral Performance Category Scale. We then determined whether "prominence of vein" scores correlated with neurologic outcomes in patients with hypoxic-ischemic injuries, and compared these results with the Barkovich magnetic resonance imaging scoring system. Patients with "normal" "prominence of vein" scores demonstrated better outcomes (mean Pediatric Cerebral Performance Category Scale value = 2) than patients with "abnormal" "prominence of vein" scores (mean Pediatric Cerebral Performance Category Scale value = 4). The dichotomized "prominence of vein" groups demonstrated correlations with the Barkovich magnetic resonance imaging scores of the proton density-weighted basal ganglia, watershed, and combined basal ganglia/watershed regions. The susceptibility-weighted imaging categorical grading scale may aid in predicting neurologic outcomes after hypoxic-ischemic injuries.

Prognostic factors and development of a scoring system for outcome of neonatal seizures in term infants

OBJECTIVE

To identify independent prognostic indicators and design a predictive scoring system for neurodevelopmental outcome for term infants who experienced clinical neonatal seizures.

STUDY DESIGN

Retrospective analysis of 120 term infants who experienced clinical neonatal seizures between July 1991 and June 2007 in a single academic pediatric neurology practice. Logistic regression analysis was applied to determine the independent prognostic indicators of an adverse outcome, which was defined as death, cerebral palsy, global developmental delay, and/or epilepsy. These indicators were then used to develop a scoring system.

RESULTS

A total of 53 infants had a normal outcome, 56 survived with one or more neurodevelopmental impairments (31 had cerebral palsy, 41 had global developmental delay, and 29 had epilepsy), and 11 died. Eleven variables were associated with adverse outcome on univariate analysis, but only method of delivery, time of seizure onset, seizure type, EEG background findings, and etiology were independent predictors on logistic regression analysis. A five-point scoring system was devised using these independent predictors with a sensitivity of 81.1% and a specificity of 84.0%.

CONCLUSIONS

In term infants, delivery via cesarean section, experiencing a seizure during the first 24 h of life, presenting with a seizure other than focal clonic, showing a moderately or severely abnormal EEG background, and having certain specific etiologies were the apparent major determinants for an adverse outcome.

The role of hypoxia-ischemia in term newborns with arterial stroke

The role of generalized hypoxia-ischemia in the genesis of perinatal focal arterial stroke remains puzzling. Animal studies have demonstrated that hypoxia-ischemia may alter blood flow through the ductus venosus, thereby increasing the risk for placental emboli entering the cerebral circulation. A retrospective review was performed of clinical records of all term newborns admitted to a tertiary perinatal center between January 1995 and May 2007 with acute arterial stroke on neuroimaging during the first week of life. Newborns were classified into 2 groups on the basis of neuroimaging abnormalities: stroke alone, or stroke and nonfocal hypoxic-ischemic brain injury. A total of 62 newborns had focal or multifocal stroke, 36 with stroke alone and 26 with stroke with nonfocal hypoxia-ischemia. Multiple risk factors for hypoxia-ischemia occurred in most newborns in both groups. These data indicate that hypoxia-ischemia may play a role in the genesis of stroke in the term newborn with or without evidence of nonfocal hypoxic-ischemic brain injury on neuroimaging.

Magnetic resonance biomarkers of neuroprotective effects in infants with hypoxic ischemic encephalopathy

Evaluation of infants with hypoxic ischemic encephalopathy by magnetic resonance spectroscopy and imaging is useful to direct clinical care, and may assist the evaluation of candidate neuroprotective therapies. Cerebral metabolites measured by magnetic resonance spectroscopy, and visual analysis of magnetic resonance images during the first 30 days after birth accurately predict later neurological outcome and are valid biomarkers of the key physiological processes underlying brain injury in neonatal hypoxic ischemic encephalopathy. Visual assessment of magnetic resonance images may also be a suitable surrogate outcome in studies of neuroprotective therapies but current magnetic resonance methods are relatively inefficient for use in early phase, first in human infant studies of novel neuroprotective therapies. However, diffusion tensor imaging and analysis of fractional anisotropy with tract-based spatial statistics promises to be a highly efficient biomarker and surrogate outcome for rapid preliminary evaluation of promising therapies for neonatal hypoxic ischemic injury. Standardisation of scanning protocols and data analysis between different scanners is essential.

Patterns of neonatal hypoxic-ischaemic brain injury

Enormous progress has been made in assessing the neonatal brain, using magnetic resonance imaging (MRI). In this review, we will describe the use of MRI and proton magnetic resonance spectroscopy in detecting different patterns of brain injury in (full-term) human neonates following hypoxic–ischaemic brain injury and indicate the relevance of these findings in predicting neurodevelopmental outcome.

Patterns of neonatal hypoxic-ischaemic brain injury

Enormous progress has been made in assessing the neonatal brain, using magnetic resonance imaging (MRI). In this review, we will describe the use of MRI and proton magnetic resonance spectroscopy in detecting different patterns of brain injury in (full-term) human neonates following hypoxic-ischaemic brain injury and indicate the relevance of these findings in predicting neurodevelopmental outcome.

Congenital heart disease and brain development

Brain and heart development occur simultaneously in the human fetus. Given the depth and complexity of these shared morphogenetic programs, it is perhaps not surprising that disruption of organogenesis in one organ will impact the development of the other. Newborns with congenital heart disease show a high frequency of acquired focal brain injury on sensitive magnetic resonance imaging studies in the perioperative period. The surprisingly high incidence of white matter injury in these term newborns suggests a unique vulnerability and may be related to a delay in brain development. These abnormalities in brain development identified with MRI in newborns with congenital heart disease might reflect abnormalities in cerebral blood flow while in utero. A complete understanding of the mechanisms of white matter injury in the term newborn with congenital heart disease will require further investigation of the timing, extent, and causes of delayed fetal brain development in the presence of congenital heart disease.

Cerebral magnetic resonance biomarkers in neonatal encephalopathy: a meta-analysis

OBJECTIVE

Accurate prediction of neurodevelopmental outcome in neonatal encephalopathy (NE) is important for clinical management and to evaluate neuroprotective therapies. We undertook a meta-analysis of the prognostic accuracy of cerebral magnetic resonance (MR) biomarkers in infants with neonatal encephalopathy.

METHODS

We reviewed all studies that compared an MR biomarker performed during the neonatal period with neurodevelopmental outcome at > or =1 year. We followed standard methods recommended by the Cochrane Diagnostic Accuracy Method group and used a random-effects model for meta-analysis. Summary receiver operating characteristic curves and forest plots of each MR biomarker were calculated. chi(2) tests examined heterogeneity.

RESULTS

Thirty-two studies (860 infants with NE) were included in the meta-analysis. For predicting adverse outcome, conventional MRI during the neonatal period (days 1-30) had a pooled sensitivity of 91% (95% confidence interval [CI]: 87%-94%) and specificity of 51% (95% CI: 45%-58%). Late MRI (days 8-30) had higher sensitivity but lower specificity than early MRI (days 1-7). Proton MR spectroscopy deep gray matter lactate/N-acetyl aspartate (Lac/NAA) peak-area ratio (days 1-30) had 82% overall pooled sensitivity (95% CI: 74%-89%) and 95% specificity (95% CI: 88%-99%). On common study analysis, Lac/NAA had better diagnostic accuracy than conventional MRI performed at any time during neonatal period. The discriminatory powers of the posterior limb of internal capsule sign and brain-water apparent diffusion coefficient were poor.

CONCLUSIONS

Deep gray matter Lac/NAA is the most accurate quantitative MR biomarker within the neonatal period for prediction of neurodevelopmental outcome after NE. Lac/NAA may be useful in early clinical management decisions and counseling parents and as a surrogate end point in clinical trials that evaluate novel neuroprotective therapies.

Evolving understanding of hypoxic-ischemic encephalopathy in the term infant

Our aim was to document changes in the evaluation and prognosis of term-born infants with neonatal encephalopathy of hypoxic-ischemic origin, with particular reference to our own experiences and influences, and to summarize the debate on causation and the relative importance of antenatal and perinatal factors. High quality neonatal cranial ultrasound and magnetic resonance imaging and spectroscopy have enabled the accurate early visualization of different patterns of hypoxic-ischemic brain injury and prediction of their associated outcomes. Long-term follow-up shows that cognitive and memory difficulties may follow even in children without motor deficits. The very early use of electrophysiologic methods has allowed broad prognostic categorization of infants when this is not possible from clinical assessment or imaging, providing a rationale for entry into intervention trials, such as therapeutic hypothermia. This work has also shown that most of these infants have evidence of acute hypoxic-ischemic brain injury that explains their symptoms and outcomes.

Advanced neuroimaging techniques for the term newborn with encephalopathy

Neonatal encephalopathy is associated with a high risk of morbidity and mortality in the neonatal period and of long-term neurodevelopmental disability in survivors. Advanced magnetic resonance techniques now play a major role in the clinical care of newborns with encephalopathy and in research addressing this important condition. From conventional magnetic resonance imaging, typical patterns of injury have been defined in neonatal encephalopathy. When applied in contemporary cohorts of newborns with encephalopathy, the patterns of brain injury on magnetic resonance imaging distinguish risk factors, clinical presentation, and risk of abnormal outcome. Advanced magnetic resonance techniques such as magnetic resonance spectroscopy, diffusion-weighted imaging, and diffusion tensor imaging provide novel perspectives on neonatal brain metabolism, microstructure, and connectivity. With the application of these imaging tools, it is increasingly apparent that brain injury commonly occurs at or near the time of birth and evolves over the first weeks of life. These observations have complemented findings from trials of emerging strategies of brain protection, such as hypothermia. Application of these advanced magnetic resonance techniques may enable the earliest possible identification of newborns at risk of neurodevelopmental impairment, thereby ensuring appropriate follow-up with rehabilitation and psychoeducational resources.