Neonatal
Echoencephalography
Tanya Nolan
Embryology

At the end of the 4th week after conception,
the cranial end of the neural tube
differentiates into 3 primary brain vesicles
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Prosencephalon (Forebrain)
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Diencephalon
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Telencephalon
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Cerebral hemispheres
Cortex & Medullary Center
Corpus Striatum
Olfactory System
Mesencephalon (midbrain)
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Thalmus
Hypothalmus
Posterior Pituitary
Cerebral Aqueduct
Superior and inferior colliculi
(quadrigeminal body)
Rhombencephalon (hindbrain)

Myelencephalon


Closed part of medulla oblongata
Metencephalon
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Pons
Cerebellum
3rd, 4th, and lateral ventricles
Choroid Plexus
Anatomy of the Neonatal Brain
Cerebrum
 2 Hemispheres (Gray and White Matter)
 Lobes of the Brain
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Frontal
Parietal
Occipital
Temporal
 Gyrus and Sulcus
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Gyrus: convulutions of the brain surface
causing infolding of the cortex
Sulcus: Groove or depression separating gyri.
Anatomy of the Neonatal Brain
Cerebrum

Fissures
 Interhemispheric
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Sylvian
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Most lateral aspect of brain
Location of middle cerebral artery
Quadrigeminal
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Area of Falx Cerebri
Posterior and inferior from the cavum
vergae
Vein of Galen posterior to fissure
Falx Cerebri
 Fibrous structure separating the 2
cerebral hemispheres
Tentorium Cerebelli
 “V” shaped echogenic extension of the
falx cerebri separating the cerebrum
and the cerebellum
Cerebrum

Basal Ganglia
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Caudate Nucleus & Lentiform
Nucleus
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Largest basal ganglia
Relay station between the
thalmus and cerebral cortex
Germinal Matrix includes
periventricular tissue and
caudate nucleus
Thalmus
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collection of gray matter
2 ovoid brain structures
Located on either side of the 3rd
ventricle superior to the
brainstem
Connects through middle of the
3rd ventricle through massa
intermedia
Hypothalmus
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“Floor” of 3rd Ventricle
Pituitary Gland is connected to
the hypothalmus by the
infundibulum
Anatomy of the Neonatal Brain
 Meninges
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Dura Mater
Arachnoid
Pia Mater
 Cerebral Spinal Fluid (CSF)

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Surrounds and protects brain and spinal cord.
40% formed by ventricles, 60% extracellular
fluid from circulation.
Ventricular System
 Lateral Ventricles: Largest of
the CSF cavities.
 Frontal Horn
 Body
 Occipital Horn
 Temporal Horn
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Trigone “Atrium”
Foramen of Monro
 3rd Ventricle
 Aqueduct of Sylvius
 4th Ventricle
 Foramen of Luschka
 Foramen of Megendie
 Cisterns

Cisterna Magna

Spaces at the base of the
skull where the arachnoid
is widely separated from
the pia mater.
Anatomy of the
Neonatal Brain
Cavum
Septum
Pellucidum

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Choroid
Plexus
Corpus Callosum
 Broad band of connective fibers between cerebral hemispheres.
 The “roof” of the lateral ventricles.
Cavum Septum Pellucidum
 Thin, triangular space filled with CSF
 Lies between the anterior horn of the lateral ventricles.
 “Floor” of the corpus callosum
Choroid Plexus
 Mass of specialized cells that regulate IV pressure by secretion/absorption of CSF
 Within atrium of the lateral ventricles
Anatomy of the Neonatal Brain
Brain Stem
 Midbrain
 Pons
 Medulla
Oblongata
Anatomy of the Neonatal Brain
Cerebellum
 Posterior cranial
fossa
 2 Hemispheres
connected by
Vermis
 3 Pairs of Nerve
Tracts
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Superior Cerebellar
Peduncles
Middle Cerebellar
Peduncles
Inferior Cerebellar
Peduncles
Cerebrovascular System
 Internal Cerebral
Arteries
 Vertebral Arteries
 Circle of Willis

Middle Cerebral
Artery

Longest branch in
Circle of Willis that
provides 80% of
blood to the
cerebral
hemispheres
Anatomy of the Neonatal Skull
 Fontanelles (“Soft Spots”)

Spaces between bones of the skull
Function and Physiology
 Cerebellum
Controls Skeletal Muscle
Movement
 Cerebral Hemispheres
 Frontal
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Parietal
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Pain, temperature, and
spatial ability
Occipital

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Voluntary muscles,
speech, emotions,
personality, morality, and
intellect
Vision
Temporal

Auditory and Olfactory
Indications for Sonographic Exam
 Cranial abnormality found on pre-natal sonogram
 Increasing head circumference with or without
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increasing intracranial pressure
Acquired or Congenital inflammatory disease
Prematurity
Diagnosis of hypoxia, hypertension, hypercapnia,
hypernaturemia, acidosis, pneumothorax, asphyxia,
apnea, seizures, coagulation defects, patent ductus
arteriosus, or elevated blood pressure
History of birth trauma or surgery
Suctioning of infant
Genetic syndromes and malformations
Sonographic Technique

What anatomy do you scan?
 Supratentorial Compartment
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Both cerebral hemispheres
Basal Ganglia
Lateral & 3rd Ventricle
Interhemispheric fissure
Subarachnoid space
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Views
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Coronal
Modified Coronal (anterior fontanelle)
Sagittal (anterior fontanelle)
Parasagittal (anterior fontanelle)
Infratentorial Compartment
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Cerebellum
Brain Stem
4th Ventricle
Basal Cisterns
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Views
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Coronal (mastoid fontanelle and occipitotemporal area)
Modified Coronal
Sagittal
Parasagittal (with increased focal depth & decreased frequency)
Coronal Scan
 Transducer placed in anterior
fontanelle with scanning plane
following coronal suture.
 Transducer angled from anterior
to posterior
 CRITICAL: images must be
symmetric!
Coronal Scan

Anterior

Orbits, anterior horns, and lateral ventricles
Anterior
• Orbits
• Anterior horns of lateral
ventricles
Coronal Scan
Middle
• Lateral
Ventricles
(Asymmetry in the
size of the lateral
ventricles can be
a common normal
variant)
• Choroid Plexus
• Cavum Septum
Pellucidum
• 3rd Ventricle
• Corpus Callosum
Coronal Scan
Posterior
• Cisterna magna
• Choroids
• Glomus of Choroids
• Occipital Lobe
Coronal Scan (Anterior)
 Cavum Septum Pellucidum
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Midline hypoechoic/cystic structure
separating the bodies and frontal horns of
the lateral ventricles.
Anterior to corpus callosum
 Caudate Nucleus
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Inferior and lateral walls of ventricles at
the body and frontal horns
Higher echogenicity in premature infants
in comparison to brain parenchyma
 Frontal Horns
 Midline Slit-like hypoechoic/cystic
formations
 Posterior “comma-like”
 Size increase from 2mm at the frontal
lobe to 3-6 mm at the choroid plexus
region.
Coronal Scan (Midline)
Choroid Plexus
• Frontal and occipital horns
devoid of choroid plexus
• Becomes enlarged at the level
of the atria & almost fills the
cavity
• Very echogenic structure
inside ventricular cavities
surrounding the thalmac nuclei
• Becomes smaller with
increased gestational age
Coronal Scan (Posterior)
• Coronal studies through the Posterior Fontanelle provides an alternate
window to visualize the choroid plexus and lateral ventricles.
Modified Coronal Scan
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
Transducer positioned over anterior
fontanelle with an angle of approximately
30-40 degrees between the scanning
plane and the surface of the fontanelle.
Demonstrates body of lateral ventricles,
3rd ventricle, and posterior fossa
(infratentorial compartment: 4th ventricle,
cerebellar hemispheres, and cisterna
magna)
 3rd Ventricle

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Not visualized in normal conditions.
Prominent in premature infants less than
32 wks
Thin and very echogenic formation seen in
midline immediately below the septum
pellucidum corresponding with the choroid
plexus and extending into the 3rd ventricle.
Sagittal and Bilateral Parasagittal Scan
 Provides most extensive visualization of the brain.
 Transducer positioned over anterior fontanelle in
sagittal plane and angled medial and lateral.
Sagittal Scan (Midline)
 Cavum Septum Pellucidum

Anechoic structure
immediately below corpus
callosum
 Corpus Callosum
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2 thin parallel lines separated
by a thin echogenic space
 3rd Ventricle
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Anechoic structure inferior to
the septum
 Cerebellum (Tentorium)
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Vermis appears echo dense
 Cisterna Magna
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Anechoic space next to
vermis
 4th Ventricle
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Small “v” oriented posteriorly
inside the echogenic vermis.
Sagittal Scan (Midline)
Supratentorial Structures
1. Choroid plexus (CP)
2. Corpus callosum (CC)
3. Septum pellucidum(SP)
4. Third ventricle (3V)
Infratentorial Structures
1. Brain stem (BS)
2. Cerebellar vermis (V)
3. Cisterna magna (CM)
4. Fourth ventricle (4V)
Parasagittal Scan (Right)
1.
Close to Midline

Caudo-thalmic groove

2.
important because subependymal hemorrhages begin in the
germinal matrix at the level of these ganglia
Slightly more lateral

anechoic frontal horns and bodies of lateral ventricles

echogenic choroid plexus (2-3 mm height)
Parasagittal Scan (Right)
1.
External to Lateral Ventricles
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White Matter

2.
Important in studying intraparenchymal hemorrhages, porencephaly, and
periventricular leukomalacia
Most Lateral Aspect
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Sylvian Fissure
Middle Cerebral Artery
Insula
Parasagittal Scan (Right)
1.
Close to Midline

Caudo-thalmic groove

2.
3.
Slightly more lateral

anechoic
C
frontal horns and bodies of lateral ventricles
T choroid plexus (2-3 mm height)

echogenic
External to Lateral Ventricles
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White Matter

4.
important because subependymal hemorrhages begin in the
germinal matrix at the level of these ganglia
Important in studying intraparenchymal hemorrhages,
porencephaly, and periventricular leukomalacia
Most Lateral Aspect

Sylvian Fissure

Middle Cerebral Artery

Insula
Parasagittal Scan\ Repeat process on
the Left
Doppler
 Typical transcranial Doppler with
imaging scan and recording from
middle cerebral artery (MCA).
 Doppler image shows circle of Willis.
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A = anterior cerebral artery
M = middle cerebral artery
P = posterior cerebral artery
RI = resistive index
 Demonstrates
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Decreased blood
flow/ischemia/infarction
Vascular abnormalities
Cerebral Edema
Hydrocephalus
Intracranial Tumors
Near-field structures
Pathology
Chiari Malformation
 Downward displacement of the cerebellar tonsils and
the medulla through the foramen magnum.
 Arnold-Chiari malformation shows a small displaced
cerebellum, absence of the cisterna magna,
malposition of the fourth ventricle, absence of the
septum pellucidum, and widening of the third
ventricle
Commonly related
to meningomyelocele

Chiari Malformation
 Sonographic Features
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Small posterior fossa
Small, displaced
Cerebellum
Possible
Myelomeningocele
Widened 3rd Ventricle
Cerebellum herniated
through enlarged foramen
magnum
4th ventricle elongated
Posterior horns enlarged
Cavum Septum
pellucidum absent
Interhemispheric Fissure
widened
Tentorium low and
hypoplastic
Holoprosencephaly

Common large central ventricle because prosencephalon
failed to cleave into separate cerebral hemispheres.
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Alobar Holoprosencephaly (Most Severe)
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Semilobar Holoprosencephaly
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Fused thalami anteriorly to a fused choroid plexus
Single midline ventricle
No falx cerebrum, corpus callosum, interhemispheric
fissure, or 3rd ventricle
Single ventricle
Presents with portions of the falx and interhemispheric
fissure
Thalmi partially separated
3rd Ventricle is rudimentary
Mild facial anomalies
Lobar Holoprosencephaly (Least Severe)
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Near complete separation of hemipsheres; only anterior
horns fused
Full development of falx and interhemispheric fissure
Holoprosencephaly
Alobar Holoprosencephaly
Semilobar Holoprosencephaly
Dandy-Walker Malformation
 Congenital anomaly of the roof of the 4th ventricle
with occlusion of the aqueduct of Sylvius and
foramina of Magendie and Luschka
 A huge 4th ventricle cyst occupies the area where the
cerebellum usually lies with secondary dilation of the
3rd ventricle; absent cerebellar vermis
Dandy-Walker Malformation
Agenesis of the Corpus Callosum
 Complete or partial absence of the connection tissue between
cerebral hemispheres
 Narrow frontal horns
 Marked separation of lateral ventricles
 Widening of occipital horns and 3rd Ventricle

“Vampire Wings”
Agenesis of the Corpus Callosum
Ventriculmegaly
 Enlargement of the ventricles
without increased head
circumference
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Communicating
Non-communicating
Resut of cerebral atrophy
 Sonographic Findings
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Ventricles greater than
normal size first noted in the
trigone and occipital horn
areas
Visualization of the 3rd and
possibly 4th ventricles
Choroid plexus appears to
“dangle” within the
ventricular trium
Thinned brain mantle in
case of cerebral atrophy
Hydrocephalus


Enlargement of ventricles with increased
head circumference
 Communicating
 Non-communicating
Sonographic Findings
 Blunted lateral angles of enlarged lateral
ventricles
 Possible intrahemispheric fissure
rupture
 Thinned brain mantle
 Aqueductal Stenosis
 Most common cause of congenital
hydrocephalus
 Aqueduct of Sylvius is narrowed or is a
small channel with blind ends;
occasionally caused by extrinsic lesions
posterior to the brain stem
 Sonographic Findings
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Widening of lateral and 3rd ventricles
Normal 4th ventricle
Hydrancephaly
 Occlusion of internal carotid
arteries resulting in necrosis
of cerebral hemispheres

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Absence of both cerebral
hemispheres with presence
of the falx, thalmus,
cerebellum, brain stem, and
postions of the occipital and
temporal lobes
Sonographic findings
 Fluid filled cranial vault
 Intact cerebellum and
midbrain
Cephalocele
 Herniation of a portion of the neural tube through a
defect in the skull
 Sonographic Findings
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Sac/pouch containing brain tissue and/or CSF and
meninges
Lateral Ventricle Enlargement
Subarachnoid Cysts
 Cysts lined with arachnoid tissue and containing CSF
 Causes
 Entrapment during embryogenesis
 Residual subdural hematoma
 Fluid extravasation sectondary to meningeal tear or
ventricular rupture
Hemorrhagic Pathology
 Subependymal-Intraventricular Hemorrhage (SEH-IVH)
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Caused by capillary bleeding in the germinal matrix
Most frequent location is the thalamic-caudate groove
Continued subependymal (SEH) bleeding pushes into the
ventricular cavity (IVH) & continues to follow CSF pathways
causing obstruction
Treatment: Ventriculoperitoneal Shunt
Since 70% of hemorrhages are asymptomatic, it is necessary
to scan babies routinely
Small IVH’s may not be seen from the anterior fontanelle
because blood tends to settle out in the posterior horns
 Risk Factors


Pre term infants
Less than 1500 grams birth weight
Hemorrhagic Pathology
 Grades
 Based on the extension of the hemorrhage
 Ventricular measurement

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
Mild dilation: 3-10 mm
Moderate dilation: 11-14 mm
Large dilation: greater than 14mm
 Grade I
Without ventricular enlargement
 Grade II
 Minimal ventricular enlargement
 Grade III
 Moderate or large ventricular enlargement
 Grade IV
 Intraparenchymal hemorrhage

Hemorrhagic Pathology
 Grade I
Hemorrhagic
Pathology
 Grade II
Hemorrhagic Pathology
 Grade III
Hemorrhagic Pathology
 Grade IV
Intraparenchymal Hemorrhage
 Brain parenchyma
destroyed
 Originally considered an
extension of IVH, but
may actually be a
primary infarction of the
periventricular and
subcortical white matter
with destruction of the
lateral wall of the
ventricle.
 Sonographic Finding

Zones of increased
echogenicity in white
matter adjacent to
lateral ventricles
Intracerebellar Hemorrhage
 Types
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Primary
Venous Infarction
Traumatic Laceration
Extension from IVH
 Sonographic Findings

Areas of increased
echogenicity within
cerebellar parenchyma

Coronal views through
mastoid fontanelle may
be essential to
differentiate from large
IVH in the cisterna
magna
Epidural Hemorrhages and Subdural
Collections
 Best diagnosed with CT because the lesions
are located peripherally along the surface of
the brain.
Ischemic-Hypoxic Lesions
 Hypoxia: Lack of adequate oxygen to the brain
 Ischemia: lack of adequate blood flow to the brain

Types
 Selective neuronal necrosis
 Status marmoratus
 Parasagittal cerebral injury
 Periventricular leukomalacia (PVL), white matter
necrosis (WMN), or cerebral edema
 Focal brain lesions (occurs when lesions are distributed
within large arteries)

Sonographic Findings
 Areas of increased echogenicity in subcortical and deep
white matter in the basal ganglia
Ischemic-Hypoxic Lesions
Periventricular Leukomalacia (PVL) or White
Matter Necrosis (WMN)
 Most important cause of abnormal neurodevelopment
in preterm infants
 Early chronic stage

Multiple cavities develop in necrotic white matter
adjacent to frontal horns
 Middle chronic Stage
 Cavities resolve and leave gliotic scars and diffuse
cerebral atrophy
 Increased Echogenicity
 Late chronic stage
 Echolucencies develop in the echolucent lesions
corresponding to the cavitary lesions in the white
matter (cysts)
PVL or WMN
1
2
4
3
ECMO
Extracorporeal Membrane Oxygenation
 Used for pulmonary
and Circulatory
Support in many
neonates to allow
additional time for lung
development
 Cannula inserted into
R internal jugular vein
and carotid artery
 Hemorrhage and
ischemia are common
in children on ECMO
Brain Infections
 Common infections referred to by TORCH
 T: Toxoplasma Gondii
 O: Other (Syphilis)
 R: Rubella Virus
 C: Cytomegalovirus
 H: Herpes Simplex Type 2
 Consequences
 Mortality
 Mental Retardation
 Developmental Delay
Ependymitis and Ventriculitis
 Ependymitis
 Irritation from hemorrhage within
the ventricle
 Occurs earlier than ventriculitis
 Sonographic Features
 Thickened, hypoechoic ependyma
(epithelial lining of the ventricles)
 Ventriculitis
 Common complication of purulent
meningitis
 Sonographic Findings
 Thin septations extending from the
walls of the lateral ventricles.