A new view of the neonatal brain: clinical utility of supplemental neurologic US imaging windows

A systematic review on intracranial aneurysm and hemorrhage detection using machine learning and deep learning techniques

The risk of discovering an intracranial aneurysm during the initial screening and follow-up screening are reported as around 11%, and 7% respectively (Zuurbie et al., 2023) to these mass effects, unruptured aneurysms frequently generate symptoms, however, the real hazard occurs when an aneurysm ruptures and results in a cerebral hemorrhage known as a subarachnoid hemorrhage. The objective is to study the multiple kinds of hemorrhage and aneurysm detection problems and develop machine and deep learning models to recognise them. Due to its early stage, subarachnoid hemorrhage, the most typical symptom after aneurysm rupture, is an important medical condition. It frequently results in severe neurological emergencies or even death. Although most aneurysms are asymptomatic and won't burst, because of their unpredictable growth, even small aneurysms are susceptible. A timely diagnosis is essential to prevent early mortality because a large percentage of hemorrhage cases present can be fatal. Physiological/imaging markers and the degree of the subarachnoid hemorrhage can be used as indicators for potential early treatments in hemorrhage. The hemodynamic pathomechanisms and microcellular environment should remain a priority for academics and medical professionals. There is still disagreement about how and when to care for aneurysms that have not ruptured despite studies reporting on the risk of rupture and outcomes. We are optimistic that with the progress in our understanding of the pathophysiology of hemorrhages and aneurysms and the advancement of artificial intelligence has made it feasible to conduct analyses with a high degree of precision, effectiveness and reliability.

Neonatal neurosonography practices: a survey of active Society for Pediatric Radiology members

BACKGROUND

While neonatal brain US is emerging as an imaging modality with greater portability, widespread availability and relative lower cost compared to MRI, it is unknown whether US is being maximized in infants to increase sensitivity in detecting intracranial pathology related to common indications such as hemorrhage, ischemia and ventriculomegaly.

OBJECTIVE

To survey active members of the Society for Pediatric Radiology (SPR) regarding their utilization of various cranial US techniques and reporting practices in neonates.

MATERIALS AND METHODS

We distributed an online 10-question survey to SPR members to assess practice patterns of neonatal cranial US including protocol details, use of additional sonographic views, perceived utility of spectral Doppler evaluation, and germinal matrix hemorrhage and ventricular size reporting preferences.

RESULTS

Of the 107 institutions represented, 90% of respondents were split evenly between free-standing children's hospitals and pediatric departments attached to a general hospital. We found that most used template reporting (72/107, 67%). The anterior fontanelle approach was standard practice (107/107, 100%). We found that posterior fontanelle views (72% sometimes, rarely or never) and high-frequency linear probes to evaluate far-field structures (52% sometimes, rarely or never) were seldom used. Results revealed a range of ways to report germinal matrix hemorrhage and measure ventricular indices to assess ventricular dilatation. There was substantial intra-institutional protocol and reporting variability as well.

CONCLUSION

Our results demonstrate high variability in neurosonography practice and reporting among active SPR members, aside from the anterior fontanelle views, template reporting and linear high-resolution near-field evaluation. Standardization of reporting germinal matrix hemorrhage and ventricular size would help ensure a more consistent application of neonatal US in research and clinical practice.

Current understanding and future potential applications of cerebral microvascular imaging in infants

Microvascular imaging is an advanced Doppler ultrasound technique that detects slow flow in microvessels by suppressing clutter signal and motion-related artifacts. The technique has been applied in several conditions to assess organ perfusion and lesion characteristics. In this pictorial review, we aim to describe current knowledge of the technique, particularly its diagnostic utility in the infant brain, and expand on the unexplored but promising clinical applications of microvascular imaging in the brain with case illustrations.

Sonographic Measurement of Brainstem Through the Foramen Magnum in Premature Neonates Can Predict Neurodevelopment Outcome?

Background: To investigate whether serial morphometric measurements of the brainstem using high resolution trans-foramen-magnum ultrasound (US) in premature neonates correlate with neurological outcomes. Methods: Serial brain ultrasound scans were performed in 36 consecutive preterm infants born at <34 weeks of gestation from birth until term-equivalent age. Two-dimensional brainstem measurements of the pons and medulla oblongata were compared with those in a cohort of 67 healthy full-term newborns. Neurologic assessment of the premature infants was assessed at 5 years of age. Results: Of the 36 preterm infants born between 25 and 34 weeks of gestation, eight had significantly delayed growth profiles in both the pons and medulla and developed neurological sequelae by 5 years of age. Conclusions: Morphometric measurements of the developing brainstem using high resolution trans-foramen-magnum ultrasound (US) may help predict neurological outcome in high-risk neonates, particularly in those who are born extremely premature.

Cause of Death in Neonates With Neurological Insults in the Neonatal Intensive Care Unit: Insights From A MITS Pilot Study

Background

Minimally invasive tissue sampling (MITS) of organs has been used as an alternative to complete diagnostic autopsy in countries where refusal for autopsy in newborns is common for sociocultural reasons. There is a paucity of literature regarding the diagnostic utility of MITS of the brain after death in neonates with neurological insults, especially in India.

Methods

This was a prospective, preliminary single-center tertiary care hospital study in India, focused specifically on MITS of the brain after neonatal death as a diagnostic tool to identify the various neurological insults. All neonatal deaths with neurological symptoms occurring within the first 30 days of life were enrolled, irrespective of the suspected clinical diagnosis.

Results

Sixteen neonates were enrolled after death for MITS of the brain, performed for diagnostic purposes, during the study period from February 2020 to March 2021. Their gestational ages ranged from 26 to 38 weeks. All neonates had either a history of seizures and/or respiratory distress or clinical evidence of sepsis and were on ventilator support. Histopathology in all 16 neonates showed evidence of anoxia, with or without reactive astrogliosis or microgliosis. In 5 neonates with cranial ultrasound evidence of brain hemorrhage, MITS of the brain showed intraventricular hemorrhage, subdural hemorrhage, or intraparenchymal white matter microhemorrhages. Premortem blood culture–proven sepsis was seen in 9 neonates. In all cases (100%), MITS had a good diagnostic yield and was useful to establish the neurological insult in the brain.

Conclusions

MITS of the brain provides an accurate and adequate diagnosis and can be an alternative to complete diagnostic autopsy for establishing the cause of death due to neurological insults, especially in low-resource settings where obtaining consent for more invasive procedure is often challenging.

Methods for Monitoring Risk of Hypoxic Damage in Fetal and Neonatal Brains: A Review

Fetal, perinatal, and neonatal asphyxia are vital health issues for the most vulnerable groups in human beings, including fetuses, newborns, and infants. Severe reduction in oxygen and blood supply to the fetal brain can cause hypoxic-ischemic encephalopathy, leading to long-term neurological disorders, including mental impairment and cerebral palsy. Such neurological disorders are major healthcare concerns. Therefore, there has been a continuous effort to develop clinically useful diagnostic tools for accurately and quantitatively measuring and monitoring blood and oxygen supply to the fetal and neonatal brain to avoid severe consequences of asphyxia Hypoxic-Ischemic Encephalopathy (HIE) and Neonatal Encephalopathy (NE). Major diagnostic technologies used for this purpose include fetal heart rate monitoring (FHRM), fetus scalp blood sampling (FBS), ultrasound (US) imaging, magnetic resonance imaging (MRI), x-ray computed tomography (CT), and nuclear medicine. In addition, given the limitations and shortcomings of traditional diagnostic methods, emerging technologies such as near-infrared spectroscopy (NIRS) and photoacoustic (PA) imaging have also been introduced as stand-alone or complementary solutions to address this critical gap in fetal and neonatal care. This review provides a thorough overview of the traditional and emerging technologies for monitoring fetal and neonatal brain oxygenation status and describes their clinical utility, performance, advantages, and disadvantages.

Cerebellar injury in premature neonates: Imaging findings and relationship with outcome

Cerebellar hemorrhagic injury (CHI) is a common complication of preterm birth. There are now many studies that have investigated the developmental consequences of CHI. This review summarizes the present state of evidence regarding the outcomes of prematurity related CHI, with a particular focus on the neuroimaging characteristics associated with adverse outcomes. Studies published to date suggest that the severity of functional deficits is dependent on injury size and topography. However, the unique contribution of the CHI to outcomes still needs to be further investigated to ensure optimal prognostic counseling.

Extended Cranial Ultrasound Views in Infants with Acute Brain Stem/Infratentorial Lesions: Diagnosis of a Progressive Midline Glioma in a 6-Week-Old Infant

Central nervous system (CNS) tumors are the most common solid tumors in children and adolescents. However, in neonates and children aged younger than a year, they are very rare. Clinical presentation in neonates is often subtle and nonspecific. When neurological symptoms are apparent at this age, cranial ultrasound (CUS) is often done as the initial evaluation, with a standard approach through the anterior fontanel (AF), followed by further imaging, such as magnetic resonance imaging (MRI), if necessary. We report the first neonatal case of a rapidly progressive diffuse midline glioma positive for histone H3 K27M mutation (World Health Organization [WHO] grade IV) in which using extended (transmastoid) CUS studies through the mastoid fontanelle (MF) in the second month of life defined the lesion in the brainstem.

Ultrasonographic approach and findings in calves with hydranencephaly

BACKGROUND

Teratogenic viral infections may proceed to hydranencephaly in cattle. Post-mortem and antemortem diagnosis can be achieved by necropsy or ultrasonography, CT-scan and MRI techniques.

OBJECTIVES

The aim of this study was to determine how effective ultrasonography approach is in detecting hydranencephaly in calves.

METHODS

In this study, ultrasonography images were obtained from brains of nine Holstein claves, of the same age, with neurological signs (due to Akabane virus infection), approaching from the caudal part of the temporal bone. To confirm the obtained images, the same approach was used to obtain images from a normal calf of the same age. The thickness of the temporal bone was measured and compared in seven affected and the healthy calves, using CT-scan images.

RESULTS

In ultrasonographic images, temporal bone (as a hyperechoic structure) and temporal cortical mantle (as an echogenic structure) were noted in the right and left side of the skull. The medial part of the image showed presence of fluid in an anechoic region, instead of brain parenchyma. Falx cerebri was also seen as a floating hyperechoic line in the middle part in all patients. There was no statistically significant difference between the thickness of temporal bone in normal and affected calves (p = 0.502). All findings were confirmed by necropsy.

CONCLUSIONS

Transtemporal approach is a novel and easy approach to study the brain in calves. This is the first study on the hydranencephalic brains of claves, using ultrasonography by transtemporal approach.

Imaging diagnosis of ventriculomegaly: fetal, neonatal, and pediatric

Ventriculomegaly is the term used to describe abnormal enlargement of ventricles in the brain. Neuroimaging, whether it is by ultrasound, computed tomography, or magnetic resonance imaging, is the key to its identification and can help to diagnose its cause and guide management in many cases. The implementation of the imaging modalities and potential differential considerations varies from the fetus, infant, and pediatric patient. Here we discuss how the imaging modalities can be used in these patient populations and review some of the differential considerations.

Pediatric encephalic ultrasonography: the essentials

Nowadays, cranial ultrasonography (US) of the newborn represents the first imaging method in brain damage study and its possible outcomes. This exam is performed using the natural fontanelles, especially the anterior one. It is fast, non-invasive and does not produce any side effect. Ultrasonographic examination is usually performed in cases of prematurity, especially in children with birth weight less than 1500 g, because important informations about the possible presence of pathologies such as cerebral hemorrhage and hypoxic-ischemic encephalopathy are given. This approach can be useful also in the study of pre- and post-natal infections, for example, type II Herpes Simplex virus or Cytomegalovirus infections, or pointing out vascular malformations such as vein of Galen aneurysm. Although less important than methods such as computed tomography (CT) and magnetic resonance imaging (MRI) in the evaluation of trauma and tumors, ultrasound can provide useful informations or be used in first instance in the suspicion of a brain mass.

State-of-the-art neonatal cerebral ultrasound: technique and reporting

In the past three decades, cerebral ultrasound (CUS) has become a trusted technique to study the neonatal brain. It is a relatively cheap, non-invasive, bedside neuroimaging method available in nearly every hospital. Traditionally, CUS was used to detect major abnormalities, such as intraventricular hemorrhage (IVH), periventricular hemorrhagic infarction, post-hemorrhagic ventricular dilatation, and (cystic) periventricular leukomalacia (cPVL). The use of different acoustic windows, such as the mastoid and posterior fontanel, and ongoing technological developments, allows for recognizing other lesion patterns (e.g., cerebellar hemorrhage, perforator stroke, developmental venous anomaly). The CUS technique is still being improved with the use of higher transducer frequencies (7.5-18 MHz), 3D applications, advances in vascular imaging (e.g. ultrafast plane wave imaging), and improved B-mode image processing. Nevertheless, the helpfulness of CUS still highly depends on observer skills, knowledge, and experience. In this special article, we discuss how to perform a dedicated state-of-the-art neonatal CUS, and we provide suggestions for structured reporting and quality assessment.

Imaging of cerebral complications of extracorporeal membrane oxygenation in infants with congenital heart disease - ultrasound with multimodality correlation

Cranial ultrasound on neonatal intensive care units is generally performed by intensive care physicians, but radiologists often provide this crucial bedside test to children on specialist paediatric cardiac intensive care units. On a paediatric cardiac intensive care unit, complex congenital cardiac conditions are commonly encountered in both pre- and postoperative scenarios, often with the use of extracorporeal membrane oxygenation (ECMO), which both increases the risks of a number of neurologic complications and results in significant changes in vascular physiology. The aim of this pictorial essay is to discuss cranial ultrasound technique, demonstrate the changes in Doppler flow profiles resulting from veno-arterial extracorporeal membrane oxygenation and congenital cardiac conditions, and illustrate commonly encountered intracranial complications of extracorporeal membrane oxygenation support in congenital cardiac care.

Ultrasound of acquired posterior fossa abnormalities in the newborn

Neonatal brain sonography is part of routine clinical practice in neonatal intensive care units, but ultrasound imaging of the posterior fossa has gained increasing attention since the burden of perinatal acquired posterior fossa abnormalities and their impact on motor and cognitive neurodevelopmental outcome have been recognized. Although magnetic resonance imaging (MRI) is often superior, posterior fossa abnormalities can be suspected or detected by optimized cranial ultrasound (CUS) scans, which allow an early and bed-side diagnosis and monitoring through sequential scans over a long period of time. Different ultrasound appearances and injury patterns of posterior fossa abnormalities are described according to gestational age at birth and characteristics of the pathogenetic insult. The aim of this review article is to describe options to improve posterior fossa sequential CUS image quality, including the use of supplemental acoustic windows, to show standard views and normal ultrasound anatomy of the posterior fossa, and to describe the ultrasound characteristics of acquired posterior fossa lesions in preterm and term infants with effect on long-term outcome. The limitations and pitfalls of CUS and the role of MRI are discussed.

Cerebellar hypoplasia of prematurity: Causes and consequences

As magnetic resonance imaging has been increasingly used to study brain injury and brain development in premature newborns, the prevalence of cerebellar abnormalities is increasingly recognized. The preterm cerebellum is highly vulnerable to a number of insults during its critical phase of growth and development throughout the period of prematurity and beyond. Direct cerebellar injury and additional factors such as supratentorial brain injury and glucocorticoid exposure adversely impact cerebellar growth and, consequently, increase the risk of neurodevelopmental disabilities. In this chapter the causes and consequences of cerebellar hypoplasia of prematurity are reviewed.

Intracranial hemorrhage in neonates: A review of etiologies, patterns and predicted clinical outcomes

Intracranial hemorrhage (ICH) in neonates often results in devastating neurodevelopmental outcomes as the neonatal period is a critical window for brain development. The neurodevelopmental outcomes in neonates with ICH are determined by the maturity of the brain, the location and extent of the hemorrhage, the specific underlying etiology and the presence of other concomitant disorders. Neonatal ICH may result from various inherited and acquired disorders. We classify the etiologies of neonatal ICH into eight main categories: (1) Hemorrhagic stroke including large focal hematoma, (2) Prematurity-related hemorrhage, (3) Bleeding diathesis, (4) Genetic causes, (5) Infection, (6) Trauma-related hemorrhage, (7) Tumor-related hemorrhage and (8) Vascular malformations. Illustrative cases showing various imaging patterns that can be helpful to predict clinical outcomes will be highlighted. Potential mimics of ICH in the neonatal period are also reviewed.

Divergent risk factors for cerebellar and intraventricular hemorrhage

OBJECTIVE

To identify whether intraventricular hemorrhage (IVH) and cerebellar hemorrhage (CH) have common or divergent risk factors.

STUDY DESIGN

This is a retrospective cross-sectional cohort of infants including all infants born <30 weeks from 2007 to 2016. Comprehensive perinatal and clinical factors were extracted from the medical record. Outborn infants, infants with major congenital anomaly, those transferred prior to discharge, and those with mixed or no brain injury were excluded. The remaining infants were divided into two groups: IVH only and CH only. Continuous variables were evaluated with the Wilcoxon-Mann-Whitney test, and categorical variables were evaluated with Fisher's exact test. Multinomial logistic regression was used to identify factors which predispose infants towards injury type more than another, holding other factors constant.

RESULTS

In total, 127 infants were included (CH n = 27, IVH n = 100). Compared to those with IVH, infants with CH were of lower EGA (p = 0.03), lower birth weight (p = 0.01), more often of multiple gestation (p = 0.03), more frequently born emergently (p = 0.03), had a greater number of ventilator days (p = 0.03), received postnatal steroids more often (p = 0.02), had a greater incidence of hemodynamically significant patent ductus arteriosus (PDA), and less frequently had pulmonary hemorrhage (p = 0.04). In multinomial regression analysis, three factors were identified which favored CH over IVH: multiple gestation (RR 4.70, 95% CI 1.56-14.21, p < 0.01), chorioamnionitis (RR 3.18, 95% CI 1.13-8.92, p = 0.03), and emergent delivery (RR 4.14, 95% CI 1.48-11.55, p < 0.01). Only advancing gestational favored IVH over CH (RR 0.74, 95% CI 0.65-0.85, p < 0.01).

CONCLUSIONS

IVH and CH have unique risk factors. These results highlight the need to tailor neuroimaging surveillance to specific patient risk factors.

Cranial Sonography in Preterm Infants with Short Review of Literature

Background:

Premature newborn infants are exposed to a wide spectrum of brain lesions which are clinically silent supporting a possible role of cerebral ultrasound screening. Aim of the study is to describe the pattern of cranial ultrasound abnormalities in preterm infants defining the short term and long term neurologic outcomes.

Material and Methods:

A hospital-based bedside cranial ultrasound was carried out at day 1, 3, 7 and follow-up scan at 3-6 months in the Department of Radio-diagnosis.

Results:

One hundred infants were included. The different abnormalities detected in cranial ultrasound of premature newborn infants include hydrocephalus in 12%, intracranial hemorrhage in 6%, brain edema in 6%, periventricular leukomalacia in 2%, choroid plexus cyst in 1%, intraventricular septa in 1% and colocephaly in 1%.

Conclusion:

Gestational age, newborn birth weight and neurologic symptoms were the most important risk factors for detecting brain lesions. The main purpose of cranial ultrasound was the demonstration or exclusion of an intracranial hemorrhage in a preterm neonate.

Ultrasound and CT of the posterior fossa in neonates

Ultrasound, CT and MRI may all be used in the evaluation of the posterior fossa in neonates depending on the clinical scenario. Ultrasonography is particularly valuable for the evaluation of the neonatal brain because of the lack of ionizing radiation and the ability to perform exams at the bedside and, importantly, advancements in ultrasound technology now allow for diagnostic-quality imaging. While CT is still the initial imaging modality of choice in most neurologic emergencies, in the neonate, ultrasound is the first line in nontraumatic emergencies. The goal of this chapter is to discuss the ultrasound technique for evaluation of the cerebellum, to describe the normal sonographic and CT appearance of posterior fossa and to provide the classical findings of the most common cerebellar abnormalities. While ultrasound is able to accurately diagnosis a majority of cerebellar abnormalities in neonates, subsequent MR imaging remains essential to confirm findings and to detect associated abnormalities.

‘State-of-the-Art’ Neonatal Cranial Ultrasound

Cranial ultrasound (cUS) provides bedside imaging access to the neonatal brain. Modern scanners and the use of various acoustic windows give detail not only of the well known pathologies met in the preterm infant, but also allow assessment of more subtle aspects of normal and abnormal brain growth and development. cUS is also very helpful in the early diagnosis of the many aetiologies of neonatal encephalopathy and seizures in the term infant and the subsequent monitoring of progress of hypoxic-ischaemic brain injury. Training issues in cUS need to be addressed.

Cranial ultrasonography of the immature cerebellum: Role and limitations

Cranial ultrasonography (CUS) is a reliable and non-invasive tool to detect frequently occurring brain abnormalities and to monitor brain development and maturation in high risk neonates. Standard CUS views are obtained through the anterior fontanel. However, evaluation of the posterior fossa is often suboptimal with this approach. Cerebellar injury occurs frequently in preterm infants and has important prognostic consequences. Early detection is therefore important. This review focuses on techniques that optimize the performance of CUS when studying the preterm cerebellum, including the use of the mastoid fontanel and the adaptation of focus points and scan frequencies. For illustration, CUS images of the normal posterior fossa anatomy as well as examples of abnormalities that may be encountered in preterm infants are included. We also discuss the limitations of CUS and the role of magnetic resonance imaging.

Quantitative analysis of cranial ultrasonographic periventricular echogenicity in relation to early neuromotor development in preterm infants

BACKGROUND

Periventricular white matter (WM) hyperechoic flares that do not evolve into cystic lesion(s) are frequently encountered on cranial ultrasonography (CUS) of preterm infants. Subjective interpretation of its presence, however, is challenging and its association with maturation and neurodevelopment remains undefined.

OBJECTIVES

To determine the relationship between quantitative WM echogenicity and postnatal and postmenstrual ages and the relationship between quantitative WM echogenicity and neuromotor development at term equivalent.

METHODS

We measured the mean pixel brightness intensity at the frontoparietal and parieto-occipital WM, choroid plexus and calvarium bone on sequential neonatal CUS scans of preterm infants born at <34 weeks gestation. The relative echogenicity (RE) was derived by dividing the mean WM echogenicity to that of the choroid plexus (RE(CP)) or bone (RE(BN)). The Lacey Assessment of the Preterm Infant was administered before discharge.

RESULTS

58 preterm infants (the mean gestational age 30.6±2.3 weeks and the mean birth weight 1211.9±224.7 g) were included. The RE(CP) of the frontoparietal WM decreased significantly with advancing postnatal and postmenstrual ages (r=-0.4, p<0.0001). The RE(BN) values of the frontoparietal and parieto-occipital WM during intermediate and late predischarge CUS studies, respectively, were significantly associated with neuromotor status at term (p<0.05). The RE(CP) and RE(BN) measured during the first week of life were not associated with neuromotor status at term.

CONCLUSIONS

Quantitative measurements of the periventricular WM echogenicity are feasible in neonatal CUSs of premature infants and may reflect microstructural developmental changes. An optimal echogenicity quantification technique and its correlation with long-term outcome remain to be determined.

Developmental cerebellar cognitive affective syndrome in ex-preterm survivors following cerebellar injury

Cerebellar injury is increasingly recognized as an important complication of very preterm birth. However, the neurodevelopmental consequences of early life cerebellar injury in prematurely born infants have not been well elucidated. We performed a literature search of studies published between 1997 and 2014 describing neurodevelopmental outcomes of preterm infants following direct cerebellar injury or indirect cerebellar injury/underdevelopment. Available data suggests that both direct and indirect mechanisms of cerebellar injury appear to stunt cerebellar growth and adversely affect neurodevelopment. This review also provides important insights into the highly integrated cerebral-cerebellar structural and functional correlates. Finally, this review highlights that early life impairment of cerebellar growth extends far beyond motor impairments and plays a critical, previously underrecognized role in the long-term cognitive, behavioral, and social deficits associated with brain injury among premature infants. These data point to a developmental form of the cerebellar cognitive affective syndrome previously described in adults. Longitudinal prospective studies using serial advanced magnetic resonance imaging techniques are needed to better delineate the full extent of the role of prematurity-related cerebellar injury and topography in the genesis of cognitive, social-behavioral dysfunction.

Cinegraphic versus Combined Static and Cinegraphic Imaging for Initial Cranial Ultrasound Screening in Premature Infants

BACKGROUND

Cranial ultrasound is an essential screening and diagnostic tool in the care of neonates and is especially useful in the premature population for evaluation of potential germinal matrix/intraventricular hemorrhage (GM/IVH). There are typically two screening examinations, with the initial cranial sonography performed between 3 days and 14 days after birth, usually consisting of a series of static images plus several cinegraphic sweeps.

OBJECTIVE

Our primary goal was to assess whether cinegraphic sweeps alone are as accurate for diagnosing neurological abnormalities as combined static and cinegraphic imaging in the initial cranial US evaluation of premature infants. Our secondary goal was to establish the difference in time required to perform these two examinations.

MATERIALS AND METHODS

We retrospectively obtained 140 consecutive initial cranial US screening studies of premature infants. Three pediatric radiologists blinded to patient data read cinegraphic images alone and also combined (dual) imaging sets for a subset of subjects, recording findings for seven disease processes: germinal matrix/intraventricular hemorrhage (GM/IVH), right or left side; periventricular leukomalacia (PVL); choroid plexus cyst; subependymal cyst; cerebral and cerebellar infarction or hemorrhage; posterior fossa hemorrhage or infarction, and extra-axial hemorrhage. Separately, we compared retrospective dual imaging acquisition time against prospectively collected cinegraphic imaging time for premature infants undergoing initial cranial US evaluation.

RESULTS

Equivalence testing demonstrated no difference in equivalency between initial cranial US screening using cinegraphic evaluation alone and dual imaging for GM/IVH, cerebral and cerebellar infarct or hemorrhage, and subependymal cyst (all P < 0.05). For PVL and choroid plexus cyst, cinegraphic imaging and dual imaging did not demonstrate equivalence (P > 0.05). Cinegraphic images were obtained in less than one-third of the time required for dual imaging.

CONCLUSION

For the diagnoses that are critical to establish at initial screening (GM/IVH, cerebral and cerebellar infarct or hemorrhage) initial cranial US screening using cinegraphic sweeps was equivalent to dual imaging. Cinegraphic imaging required significantly less time to perform than dual imaging. We suggest that performance of cranial US screening using cinegraphic imaging alone is a potentially advantageous option in the initial evaluation of the premature neonate.

Cerebellar injury in preterm children with cerebral palsy after intraventricular hemorrhage: Prevalence and relationship to functional outcomes

OBJECTIVES

To elucidate the prevalence of cerebellar injury and its relationship to functional outcomes in preterm children with cerebral palsy (CP) after intraventricular hemorrhage (IVH).

PARTICIPANTS

We selected 69 children (40 males and 29 females, aged between 6 and 13 years) out of 2049 with cerebral palsy who visited Morinomiya Hospital, the regional center hospital for CP in West Japan. The inclusion criteria were (1) gestational age under 36 weeks at birth, (2) clear history of postnatal intraventricular hemorrhage, and (3) age at investigation over 6 years old. Those without sufficient imaging study or functional evaluation were excluded.

METHODS

The participants were divided into four groups according to the presence of post-hemorrhagic hydrocephalus (PH) and cerebellar injury (CI): PH+/CI+, PH+/CI-, PH-/CI+, and PH-/CI-. Type of CP, ability to walk, verbal function, the incidence of severe visual impairment, and the complication of epilepsy were investigated and compared among the groups.

RESULTS

The gestational ages of the participants were between 22 and 34 weeks, and their birth weight was between 412 and 1788 g. PH and CI were found in 39 (57%) and 40 (58%) children, respectively. Both the PH+/CI+ group (n=31) and the PH-/CI+ group (n=9) showed significantly lower walking and verbal abilities and a higher incidence of epilepsy than the PH-/CI- group (n=21), while the PH+/CI- group showed no significant difference from the PH-/CI- group. Severe visual impairment was found only in the PH+/CI+ group and the PH-/CI+ group.

CONCLUSIONS

The prevalence of CI in preterm children with CP after IVH (58%) was almost the same as that of PH. CI is one of the most significant complications in preterm infants, affecting motor and verbal functions and being associated with epilepsy more than PH.

Posterior fossa abnormalities in high-risk term infants: comparison of ultrasound and MRI

Objectives

We aimed to assess the characteristics of posterior fossa (PF) abnormalities in a cohort of high-risk term neonates, as well as the diagnostic performance of cranial ultrasound (CUS) with additional mastoid fontanelle (MF) views for the detection of these abnormalities, with magnetic resonance imaging (MRI) being the reference standard.

Methods

In this retrospective study, 113 term neonates with CUS and subsequent MRI were included. Sensitivity, specificity, and predictive values of routine CUS and CUS with MF views were calculated.

Results

Posterior fossa abnormalities were diagnosed on CUS in 46 of 113 infants. MRI confirmed these findings in 43 and showed additional abnormalities in 32 infants. The sensitivity and specificity of anterior fontanelle views for major PF abnormalities as seen on MRI were 16 % and 99 %. Adding MF views increased the sensitivity of US to 82 %. The sensitivity and specificity of MF views for the detection of any (major or minor) PF abnormality were 57 % and 95 %. Especially acute hypoxic-ischemic injury and small subdural and punctate cerebellar haemorrhage remained undetected by CUS.

Conclusions

PF abnormalities are frequent in high-risk term infants. MF-CUS enables early diagnosis of major PF abnormalities. We therefore advocate to perform MF-CUS in high-risk term neonates.

Key Points

• Posterior fossa abnormalities are a frequent finding in high-risk term infants.

• Adding mastoid fontanelle views improves ultrasound detection of clinically relevant abnormalities.

• Hypoxic-ischemic injury and small posterior fossa haemorrhages are better detected with MRI.

• Cranial ultrasound examination should include mastoid fontanelle views in high-risk term neonates.

State of the art cranial ultrasound imaging in neonates

Cranial ultrasound (CUS) is a reputable tool for brain imaging in critically ill neonates. It is safe, relatively cheap and easy to use, even when a patient is unstable. In addition it is radiation-free and allows serial imaging. CUS possibilities have steadily expanded. However, in many neonatal intensive care units, these possibilities are not optimally used. We present a comprehensive approach for neonatal CUS, focusing on optimal settings, different probes, multiple acoustic windows and Doppler techniques. This approach is suited for both routine clinical practice and research purposes. In a live demonstration, we show how this technique is performed in the neonatal intensive care unit. Using optimal settings and probes allows for better imaging quality and improves the diagnostic value of CUS in experienced hands. Traditionally, images are obtained through the anterior fontanel. Use of supplemental acoustic windows (lambdoid, mastoid, and lateral fontanels) improves detection of brain injury. Adding Doppler studies allows screening of patency of large intracranial arteries and veins. Flow velocities and indices can be obtained. Doppler CUS offers the possibility of detecting cerebral sinovenous thrombosis at an early stage, creating a window for therapeutic intervention prior to thrombosis-induced tissue damage. Equipment, data storage and safety aspects are also addressed.

Neonatal neurosonography: A pictorial essay

Neurosonography is a simple, established non-invasive technique for the intracranial assessment of preterm neonate. Apart from established indication in the evaluation of periventricular haemorrhage, it provides clue to wide range of pathology. This presentation provides a quick roadmap to the technique, imaging anatomy and spectrum of pathological imaging appearances encountered in neonates.

Cranial sonography in extremely preterm infants

Survival rates of extremely preterm infants have risen dramatically, paralleling improvements in prenatal and neonatal care. Cranial sonography is the primary imaging technique for the evaluation of brain injury in these patients. Extremely preterm infants have some unique features related to ongoing maturation, and associated findings on cranial sonography should be considered for accurate and early diagnosis. The aim of this pictorial essay is to illustrate normal anatomy, normal variants, and pitfalls that lead to misinterpretation of cranial sonography in extremely preterm infants.

Cerebellar hemorrhagic injury in premature infants occurs during a vulnerable developmental period and is associated with wider neuropathology

BACKGROUND

Cerebellar hemorrhagic injury (CHI) is being recognized more frequently in premature infants. However, much of what we know about CHI neuropathology is from autopsy studies that date back to a prior era of neonatal intensive care. To update and expand our knowledge of CHI we reviewed autopsy materials and medical records of all live-born preterm infants (<37 weeks gestation) autopsied at our institution from 1999-2010 who had destructive hemorrhagic injury to cerebellar parenchyma (n = 19) and compared them to matched non-CHI controls (n = 26).

RESULTS

CHI occurred at a mean gestational age of 25 weeks and involved the ventral aspect of the posterior lobe in almost all cases. CHI arose as a large hemorrhage or as multiple smaller hemorrhages in the emerging internal granule cell layer of the developing cortex or in the nearby white matter. Supratentorial germinal matrix hemorrhage occurred in 95% (18/19) of CHI cases compared to 54% (14/26) of control cases (p = 0.003). The cerebellar cortex frequently showed focal neuronal loss and gliosis (both 15/19, 79%) in CHI cases compared to control cases (both 1/26, 4% p < 0.0001). The cerebellar dentate had more neuronal loss (8/15, 53%) and gliosis (9/15, 60%) in CHI cases than controls (both 0/23, 0%; p < 0.0001). The inferior olivary nuclei showed significantly more neuronal loss in CHI (10/17, 59%) than in control cases (5/26, 19%) (p = 0.0077). All other gray matter sites examined showed no significant difference in the incidence of neuronal loss or gliosis between CHI and controls.

CONCLUSIONS

We favor the possibility that CHI represents a primary hemorrhage arising due to the effects of impaired autoregulation in a delicate vascular bed. The incidences of neuronal loss and gliosis in the inferior olivary and dentate nuclei, critical cerebellar input and output structures, respectively were higher in CHI compared to control cases and may represent a transsynpatic degenerative process. CHI occurs during a critical developmental period and may render the cerebellum vulnerable to additional deficits if cerebellar growth and neuronal connectivity are not established as expected. Therefore, CHI has the potential to significantly impact neurodevelopmental outcome in survivors.

Cerebellar hemorrhage in very low birth weight premature infants: the advantage of the posterolateral fontanelle view

OBJECTIVE

The purpose of this study was to determine the prevalence of cerebellar hemorrhage in very low birth weight infants using the posterolateral fontanelle for ultrasound (US) examination.

METHODS

The study included 125 very low birth weight premature infants (defined as equal or less than 1500 grams at birth) hospitalized in the premature or neonatal intensive care departments that had at least one head US examination including both anterior and posterolateral fontanelle scans.

RESULTS

On US performed through the posterolateral fontanelle, four (3.2%) infants had echogenic posterior fossa lesions interpreted as hemorrhages. None of these lesions were initially or retrospectively observed through the standard anterior fontanelle scan. Two infants died at age 4 and 39 days, respectively. All survivors are being followed up in the hospital's neurodevelopment outpatient clinic.

CONCLUSIONS

Cerebellar hemorrhage may be overlooked on standard anterior fontanelle views. The posterolateral approach may assist in diagnosing these lesions.

Accuracy of head ultrasound for the detection of intracranial hemorrhage in preterm neonates: comparison with brain MRI and susceptibility-weighted imaging

OBJECTIVES

To evaluate the sensitivity and specificity of head ultrasound (HUS) in the detection of intracranial hemorrhage in premature neonates compared with brain MRI using susceptibility-weighted imaging (SWI).

MATERIAL AND METHODS

Ultrasound (US) and MRI scans of the brain using SWI in premature neonates were retrospectively evaluated for grade I-III germinal matrix hemorrhage (GMH), periventricular hemorrhagic infarction (PVHI), intra-axial hemorrhage other than PVHI, extra-axial hemorrhage in each cerebral hemisphere and cerebellar hemorrhage in each cerebellar hemisphere. The impact of these hemorrhagic findings on short-term clinical management was also reviewed.

RESULTS

Twelve neonates (mean age: 9.8 days; range: 3-23 days) with a mean gestational age of 32.8 weeks (range: 29.6-35.4 weeks) were included in the study. HUS had high sensitivity (100%) and specificity (93.3%) in detecting grade III GMH using SWI as a reference, but poor sensitivity (0%) in the detection of intraventricular hemorrhage with normal-sized ventricles (grade II GMH). US was not sensitive in detecting either small cerebellar or extra-axial hemorrhage.

CONCLUSION

HUS was highly sensitive and specific in the evaluation of grade III GMH, whereas SWI was superior to HUS in detecting small intra-axial or extra-axial hemorrhage, and had no impact on short-term management. Given the low cost, lack of radiation and advantages of bedside evaluation, HUS should continue to be the first line of imaging for brain injury in the evaluation of premature neonates with suspected intracranial hemorrhage. However, the usefulness of SWI for predicting long-term neurological outcomes has yet to be determined.

Demonstration of fourth ventricular choroid plexus on neonatal cranial ultrasonography

The choroid plexus of the fourth ventricle can be identified on neonatal cranial US via the mastoid fontanelle, particularly when transducers of high frequency are used. Its presence as a normal, echogenic structure might not be appreciated by all sonographers. It should not be mistaken for vermian hemorrhage or clotted blood within the fourth ventricle or cisterna magna.

Ultrasound detection of posterior fossa abnormalities in full-term neonates

Routine cranial ultrasonography, using the anterior fontanelle as acoustic window enables visualization of the supratentorial brain structures in neonates and young infants. The mastoid fontanelle enables a better view of the infratentorial structures, especially cerebellar hemorrhage in preterm infants. Reports on the usefulness and reliability of cranial ultrasonography using the mastoid fontanelle approach for the detection of posterior fossa abnormalities, focusing only on full-term neonates are limited. This article describes the technique of mastoid fontanelle ultrasonography in full-term neonates and the features of posterior fossa abnormalities that may be encountered in various neonatal disorders and conditions, combined with subsequent MRI in the same patients. Cranial ultrasound through the mastoid fontanelle plays a pivotal role in the early detection of posterior fossa pathology and selection of neonates with an indication for MRI.

Cerebellar haemorrhage in the extremely preterm infant

AIM

The aim of this study was to investigate the incidence, risk factors and developmental outcomes of cerebellar haemorrhage in the extremely preterm infant.

METHODS

Over a 4-year period from January 2004, all patients with cerebellar haemorrhage born at 24-27 weeks gestation or with a birthweight < 1000 g were identified from database review. All patients had cranial ultrasound scans including views from the mastoid fontanelle. To verify the incidence, a review of all reports over the 4-year period and a review of all cranial imaging over a 2-year period were carried out.

RESULTS

From the data analysed on 339 neonates, five cases of cerebellar haemorrhage were identified, four on ultrasound scan (1.2%) and one on magnetic resonance imaging (1.5% total). Two cases were associated with grade III peri-intraventricular haemorrhage. The cases had diverse maternal, antenatal and post-natal risk factors. The two with associated peri-intraventricular haemorrhage have developmental delay. The cases with isolated cerebellar haemorrhage had good neurodevelopmental outcomes.

CONCLUSIONS

A low incidence of cerebellar haemorrhage identified from the mastoid fontanelle was demonstrated. The neurodevelopmental outcome was better than that described in previous reports.

Head Ultrasound and MR imaging in the evaluation of neonatal encephalopathy: competitive or complementary imaging studies?

Magnetic resonance (MR) imaging is superior to ultrasonography (US) for the evaluation and prognostication of neonates with neonatal encephalopathy (NE). Nonetheless, US may provide important information early in the course of NE and can be used to document the evolution of lesions. This article provides an overview of useful findings in the US evaluation of infants with NE. Although many of the findings do not appear as conspicuous or as extensively as they do on MR imaging, recognition and familiarity with subtle head US abnormalities may allow head US to play an important complementary role to MR imaging in the evaluation of infants with NE.

State-of-the-art cranial sonography: Part 1, modern techniques and image interpretation

OBJECTIVE

In this era of radiation awareness, high-quality ultrasound is more important than ever. Although cranial sonography equipment has advanced greatly, application of modern techniques has not been utilized in a fashion commensurate to other cross-sectional modalities. This article will describe modern cranial sonography techniques, including the utility of linear imaging, use of additional fontanels, and screening Doppler imaging.

CONCLUSION

When modern protocols are used, cranial sonography is highly accurate for the detection of cranial abnormalities.

State-of-the-art cranial sonography: Part 2, pitfalls and variants

OBJECTIVE

In the first part of this article, modern cranial sonography techniques and interpretation were discussed, emphasizing ways in which the application of modern imaging technology and techniques are able to enhance detection of pathologic abnormalities on cranial sonography.

CONCLUSION

In this part of the article, we will describe pitfalls and variants that may be confused with pathologic abnormalities. Emphasis will be placed on recognizing normal variations and distinguishing them from pathologic abnormalities that may require additional imaging or clinical follow-up.

Diagnosis of an intraventricular hemorrhage by a pediatric emergency medicine attending using point-of-care ultrasound: a case report

For the past 2 decades, point-of-care ultrasound (POCU) has been increasingly performed in adult emergency medicine for a variety of indications. However, the incorporation of POCU into pediatric emergency medicine has been much slower. Cranial ultrasound is an integral part in neonatology and is routinely used to diagnose intraventricular hemorrhage (IVH). Although cranial ultrasound is not considered a core emergency ultrasound application in the 2008 American College of Emergency Physicians ultrasound guidelines, this novel approach may prove beneficial in the emergency department (ED) setting. We report a case of a 16-day-old male that presented to the pediatric ED with fussiness and found to be anemic. An IVH was diagnosed for the first time using POCU by a pediatric ED attending. Sonographic characteristics of an IVH may be helpful in the prompt diagnosis of this condition, thereby reducing morbidity and mortality and improving the final outcome.

Neonatal encephalopathy: a prospective comparison of head US and MRI

BACKGROUND

Head US, the cornerstone neuroimaging modality in neonates, is believed to be less sensitive than MRI for detecting hypoxic ischemic injury (HII). Most reports comparing these modalities are retrospective and have a long interval between the exams.

OBJECTIVE

To prospectively characterize the range of abnormalities found in US examinations performed within 2 h of brain MRI in encephalopathic neonates.

MATERIALS AND METHODS

A total of 76 consecutive exams met our inclusion criteria. Diagnostic performance of the US images was prospectively compared with MRI.

RESULTS

MRI was considered positive for HII in 53 neonates. Of the remaining 23, MRI was negative for HII in 9, showed white matter abnormalities unrelated to HII in 8, and was inconclusive in 6. Of the 70 neonates with conclusive examinations, the US exam was regarded as positive in 67. Diagnostic accuracy of US was 95.7%.

CONCLUSION

Our study demonstrates that US should still be regarded as a screening test in neonates. US is more sensitive for the detection of injury than previously reported, and more attention should be paid to proper US technique. MRI shows disease more extensively and should be accomplished as early as possible.