Reasons for ultrasound exam of the neonatal head

hemorrhages around lateral ventricle

What happen in neonates under 34 weeks?

intraventricular and subependymal hemorrhages

How often do intraventricular and subependymal hemorrhages occur?

40 to 70% in neonates under 34 weeks

What is the most common ischemic lesion in a premie brain?

Periventricular leukomalacia

What is another name for Periventricular leukomalacia?

multifocal white matter necrosis

What is Periventricular leukomalacia?

when blood vessels burst, blood clots can collect in the white matter

What is Periventricular leukomalacia a predictor of?

Cerebral palsy

How often does Periventricular leukomalacia occur?

12 to 20% in infants weighing less than 2000g

Which lobe controls motor function?

frontal

Which lobe controls sensory function?

parietal

Which lobe controls audibility and olfactory function?

temporal

Which lobe controls vision function?

occipital

What controls balance?

cerebellum

Name the fontanelles

anterior

posterior

lateral

When does the anterior fontanelle close?

commonly around 6 months

What connects the 3rd and 4th ventricle?

Aqueduct of Sylvius

What connects the 4th ventricle and the spinal cord?

Foramen of Magendie

What connects the 4th ventricle and the subarachnoid space?

foramen of Luschka

What forms the roof of the lateral ventricles?

corpus callosum

What is below the corpus callosum and forms the medial walls of the lateral ventricles?

Cavum septum pellucidum

CSP

Where do all horns of the lateral ventricles merge?

trigone/atrium region

What connects the lateral ventricles and the 3rd ventricle?

Foramen of Monroe

What is the connection between the two hemispheres?

Messa intermedius

What makes up the floor of the 3rd ventricle?

hypothalamus.

What is the narrow subarachnoid space surrounding the brain and spinal cord?

Cistern

What is the largest of the cisterns?

cisterna magna

What does the narrow subarachnoid space surrounding the brain and spinal cord contain?

CSF

The _______, along with the cavum septum pellucidum (CSP) is a persistence of the embryological fluid-filled space between the leaflets of the septum pellucidum

Cavum Vergae

What forms the lateral borders of the frontal horns?

caudate nucleus

What does the caudate nucleus consist of?

head, body and tail

Where is a common site for hemorrhage on the caudate nucleus?

head

What does the brain stem consist of?

midbrain

pons

medulla oblongata

What is the cerebral peduncles responsible for?

communication between cerebellum and the sensory nerves

thalami and cerebellum

How is the midbrain divided?

into two cerebral peduncles

Thalami > cerebellum > sensory & balance

Explain the circle of willis.

the two vertebral arteries come together to form the basilar artery

the basilar divides posterior cerebral artery

the internal carotid artery turns into the middle cerebral artery

the posterior communicating artery connects the posterior cerebral and the middle cerebral arteries

the anterior cerebral artery branches off the middle cerebral artery

the anterior communicating artery connects the two anterior cerebral arteries

Where does the middle cerebral artery extend?

into the sylvian fissure Y

Why is ultrasound the exam of choice when there is an open fontanelle?

portable

inexpensive

non-invasive

requires no sedation

Which transducer should be used for a neonate head scan?

5 MHz to 10 MHz phased array is optimal

small linear array may also be used

Where is the notch pointing during a neonate head scan?

toward the patients nose

In what is the orientation of a sagittal view image of a neonate head scan?

top - superior - superficial

bottom - inferior - deep

right - anterior

left - posterior

In what is the orientation of a coronal view image of a neonate head scan?

top - superior - superficial

bottom - inferior - deep

right - left

left - right

Explain the coronal view image of a neonate head scan.

slowly angle through the coronal plane

beginning rostrally at the frontal lobes angle posteriorly

What is the patient prep for a neonatal cranial exam?

The infant should be disturbed as little as possible. The exam should be done in the neonatal unit. Transducer gel should be body temperature.

How do you explain the cranial exam?

If the parents or guardians are available the sonographer should explain the exam is being performed to visualize the structures of the cranium for possible defects or problems that might arise in the premature infant.

How should the patient dress for the exam?

Keep the infant as warm as possible.

What transducer should be used for an infant weighing less than 1500 grams or less than 32 weeks?

7.5 MHz sector is a good choice but a curve linear transducer may also be used.

What transducer should be used when examining a full term infant?

3 – 5 MHz sector is a good choice but a curve linear transducer may also be used.

Explain the cranial procedure.

Begin doing a full sweep through the anterior fontanelle. Starting perpendicularly with a coronal view, slowly angle the transducer toward the face, scanning through the anterior horns and through the frontal lobes. Then slowly angle toward the occipital lobes and the posterior portion of the cranium and back to perpendicular. Change to a sagittal view, once again beginning perpendicular sweep the transducer toward the right lateral horn and through the temporal lobe and back to perpendicular. Repeat on the left side through the left lateral horn and temporal lobe. Finish back at a perpendicular position.

Look for:

• Hemorrhage
• Defects
• Size
• Vascularity
• Fluid
• Masses

After scanning through the brain start taking images.

Document the normal anatomy and any pathology found, including measurements and vascularity if indicated

What medical history is pertinent to a Neonate cranial exam?

Sex

Gestational Age

Weight

Family History

Anomalies previously found

What is the patient position during a neonate cranial exam?

Supine with the head facing up

Prone with head facing the side may be used as necessary

What are the scan planes for a neonatal cranial exam?

Coronal & Sagittal

Explain the coronal plane in a neonatal cranial exam?

Begin perpendicular to the anterior fontanelle, angle the transducer toward the face return midline and sweep the posterior.

Explain the sagittal plane in a neonatal cranial exam?

Begin perpendicular to the anterior fontanelle, Angle the transducer to the right return midline and sweep the left

What are the techniques used for a neonatal cranial exam?

Scanning a baby while they sleep is easier on the patient and easier for scanning

Explain the neonatal anatomy

After the fourth week after conception the neural tube separates into three main structures that will form the brain. These structures include the prosencephalon (forebrain) , mesencephalon (midbrain) and rhombencephalon (hindbrain).

The forebrain consists of the cerebrum, thalamus, hypothalamus and the diencephalon. The midbrain will develop into ventricles and the cerebral peduncles. The hindbrain will develop into the cerebellum and the brain stem including the medulla oblongata and pons

What is the purpose of the ventricles?

Four ventricles circulate cerebral spinal fluid around the brain.

Explain the anatomy of the lateral ventricles.

divided into the frontal, occipital and temporal temporal horns. All horns converge at the trigone region. They are filled with cerebral spinal fluid.

Explain the anatomy of the third ventricles.

The third ventricle is a midline structure containing cerebral spinal fluid. It is connected with the lateral ventricles by the foramen of Monroe and to the forth ventricle by the aqueduct of sylvius.

Explain the anatomy of the fourth ventricles.

The fourth ventricle is also filled with cerebral spinal fluid.

Explain the anatomy of the Corpus Callosum.

Lies midline and consists of connective fibers connecting the two hemispheres. It creates the roof of the lateral ventricles and sits superior to the cavum septum.

Explain the anatomy of the Cavum Septum Perdiculum and Vergae.

A midline structure that creates the floor of the corpus callosum. It is filled with cerebral spinal fluid. It sits between the lateral ventricles. It is present at birth but closes around 4 months.

Explain the anatomy of the Thalamus.

The thalamus is an egg-shaped structure. It sits within the 3^rd

Explain the anatomy of the Cerebellum.

The cerebellum takes up most of the posterior fossa. The connection between each lobe is called the vermis.

Explain the anatomy of the Cisterna Magna.

Lies posteroinferior to the cerebellum.

Explain the anatomy of the Choroid Plexus.

Consists of two curved structures that wrap around the thalamus. It is responsible for absorbing cerebral spinal fluid.

Explain the anatomy of the Aqueduct of Sylvius.

channels that connects the 3^rd and 4^th ventricle

Explain the anatomy of the Foramen of Monroe.

channels connecting the lateral ventricle with the 3^rd ventricle

Explain the anatomy of the Brain Stem.

Consists of the midbrain, pons and medulla oblongata. This structure connects the spinal cord to the brain.

Explain the anatomy of the Interhemispheric Fissure.

A midline structure where the falx lies between the two hemispheres.

Explain the anatomy of the Massa Intermedia.

A pea-shaped structure within the 3^rd

Explain the anatomy of the Hippocampal Gyrus (Choroid Fissure).

spiral-like fold covering the temporal horns.

Explain the anatomy of the Cerebral Peduncles.

Column like structures connected to the pons and the thalamus

Explain the anatomy of the Sulci.

fissures of the brain that separate the folds.

Explain the anatomy of the Tentorium.

echogenic covering that separates the cerebellum from the cerebral. It is part of the dura mater.

Explain the anatomy of the Sylvian Fissure.

A fissure located laterally between the temporal and frontal lobes. The middle cerebral artery lies in this fissure.

Explain the anatomy of the Caudate Nucleus.

located within the concavity of the lateral angles of each ventricle.

Explain the anatomy of the Germinal Matrix/Caudothalmic Groove.

A vascular network located near the caudate nucleus. This is a common site for hemorrhage in the neonate infant.

Explain the anatomy of the Quadrigeminal Plate.

Immediately superior to the superior aspect of the tentorium.

What are appropriate reasons for a neonate cranial exam?

Evaluate the cranial anatomy of a neonate infant for pathology including: anomalies, intracranial hemorrhage, and ventricular dilation

Premature Delivery

Abnormal posturing

Low birth weight

Seizers

Apnea

coma

What are the required coronal images?

Anterior: orbits

Anterior: anterior horns and lateral ventricles

Middle: lateral ventricles, cavum septum pellucidum, 3^rd ventricle, and corpus callosum

Posterior: ambient wings of the cisterna magnum

Posterior: tentorium and cisterna magnum

Posterior: choroid plexus

Posterior: glomus of choroids

Posterior: occipital lobe

What are the required sagittal images?

Midline: cavum septum pellucidum, corpus callosum, 3^rd ventricle and foramen of Monroe, aquaduct of slyvius, 4^th ventricle, tentorium, cisterna magna

Left Thalamus

Left Caudothalamic groove

Left Lateral ventricle: anterior, body, and occipital (temporal is hydrocephalic

Left Angle slightly lateral from lateral ventricle to show the white matter

Left very lateral: Sylvain fissure/ middle cerebral artery

Repeat on left side

What is the sonographic appearance of the ventricles?

Two Lateral Ventricles: filled with cerebral spinal fluid and appear as echogenic slits.

Third Ventricle: Midline structure, echogenic walls and the center appears anechoic.

Forth Ventricle: Midline structure inferior to the third ventricle, echogenic walls and the center appears anechoic.

What is the sonographic appearance of the Corpus Callosum?

midline, echogenic structure, midgray and has medium to low level echoes.

What is the sonographic appearance of the Cavum Septum Perdiculum and Vergae?

appears anechoic, fluid filled structure. Anterior to the corpus callosum

What is the sonographic appearance of the Thalamus?

midline, echogenic structure within the 3^rd ventricle

What is the sonographic appearance of the Cerebellum?

vermis is echogenic and the surrounding parenchyma appears midgray

What is the sonographic appearance of the Cisterna Magna?

fluid filled, anechoic structure lays posteroinferior to the cerebellum

What is the sonographic appearance of the Choroid Plexus?

echogenic structures that wrap around the thalamus

What is the sonographic appearance of the Aqueduct of Sylvius?

rarely seen during ultrasound unless dilated

What is the sonographic appearance of the Foramen of Monroe?

channels connecting the lateral ventricle with the 3^rd ventricle

What is the sonographic appearance of the Brain Stem?

appears midgray with low echogenicity

What is the sonographic appearance of the Interhemispheric Fissure?

echogenic area separating the two hemispheres

What is the sonographic appearance of the Massa Intermedia?

mid-gray, best seen with ventricular dilatation

What is the sonographic appearance of the Hippocampal Gyrus (Choroid Fissure)?

echogenic, spiral-like fold coving the temporal horn.

What is the sonographic appearance of the Cerebral Peduncles?

Column like structures connected to the pons and the thalamus

What is the sonographic appearance of the Sulci?

echogenic spider- like fissures of the brain that separate the folds.

What is the sonographic appearance of the Tentorium?

echogenic covering that separates the cerebellum from the cerebral.

What is the sonographic appearance of the Sylvian Fissure?

A fissure located laterally between the temporal and frontal lobes. It appears as a Y shape. The middle cerebral artery lies in this fissure.

What is the sonographic appearance of the Caudate Nucleus?

appears midgrey

What is the sonographic appearance of the Germinal Matrix/Caudothalmic Groove?

small echogenic area at the junction of the caudate and the thalamus . hemorrhages are common here.

What is the sonographic appearance of the Quadrigeminal Plate?

echogenic area superior to the tentorium.

What is Arnold-Chiari Malformations?

Congenital anomaly associated with spina bifida. The brain stem and cerebellum are pulled toward the spinal cord, secondary hydocephus develops.

What is the sonographic appearance of Arnold-Chiari Malformations?

Small posterior fossa

Myelomeningocele decompression of the ventricle

Small cerebellum

Absence of the cisterna magna

4^th ventricle in low position

Absence of the septum pellucidum

Widening of the 3^rd ventricle

Cerebellar tonsil herniation into enlarged foramen magna

Displacement of pons and medulla

Elongation of 4^th ventricle

Enlarged massa intermedia

3^rd ventricle slightly larger

Small anterior horns

Enlargement of posterior horns

Wide interhemispheric fissure

Small posterior fossa

Low tentorium

Hydrocephalus

What are the presenting symptoms of Arnold-Chiari Malformations?

40 to 75% aqueductal stenosis

What is Agenesis of the Corpus Callosum?

Partial or complete agenesis is often seen with heterotopias and polymicrogyria.

What is the sonographic appearance of Agenesis of the Corpus Callosum?

Narrow frontal horns

Separation of the anterior horns

Widening of the occipital horns

Widening of the 3^rd ventricles

3^rd ventricles have pointed upper corners (bat-wings)

What are the presenting symptoms of Agenesis of the Corpus Callosum?

poor muscle tone

porencephaly

hydrocephalus

microgyria

Arnold-Chiari

fusion of the hemispheres.

What is Dandy-Walker Malformation?

A congenital anomaly in which a 4^th ventricle cyst occupies the cerebellar space.

What is the sonographic appearance of Dandy-Walker Malformation?

Hydroplasia of cerebellar vermis

Enlarged 4^th ventricle

Cysts in posterior fossa

Small brain stem

Hydrocephalus

Atresia of the Luschka and Magendie

4^th ventricle communicates directly to cysts

Obstruction above and below 4^th ventricle

Absence of Corpus Callosum

What are the presenting symptoms of Dandy-Walker Malformation?

hydrocephalus

agenesis of the corpus callosum

encephalocele

holoprosencephaly

microcephaly

infundibular hamartomas

brain stem lipomas.

What is Holoprosencephaly?

Complex abnormality from failure of cleavage of the prosencephalon

*Must obtain modified coronal studies of the whole frontal lobe to determine if frontal horns are present

What is Alobar Holoprosencephaly?

The most severe form of Holoprosencephaly

What is the sonographic appearance of Alobar Holoprosencephaly?

Single midline ventricle

Thin, primitive cerebral cortex

Fused Thalami and hemispheres , hyper echogenic choroid plexus

Absent corpus callosum & interhemiphermic fissure, 3^rd ventricle

Large dorsal cyst

What are the presenting symptoms of Alobar Holoprosencephaly?

Multiple facial abnormalities

• cebocephaly
• cyclopia
• ethmocephaly

What is Semilobar Holoprosencephaly?

Characterized by the abnormal storage and collection of glycogen in the tissue of the liver and kidneys.

What is the sonographic appearance of Semilobar Holoprosencephaly?

Single ventricle

More brain parenchyma present

Posterior faux and interhemispheric fissure

Splenium and genu seen midline

3rd ventricle is small

What are the presenting symptoms of Semilobar Holoprosencephaly?

Mild facial

• hypotelorism
• cleft lip

What is lobar Holoprosencephaly?

Least severe form

What is the sonographic appearance of lobar Holoprosencephaly?

Nearly complete separation of hemispheres

Faux and interhemispheric fissure development

Some front lobe fusion

Absent septum pellucidum

Anterior horns fused

Occipital horns separation

3^rd ventricle separates the thalami

Absent genu

What are the presenting symptoms of lobar Holoprosencephaly?

mild facial abnormalities

What is Ischemic Lesions: ?

Lesions in the midline that induce malformations of the telencephalon

What is the sonographic appearance of Ischemic Lesions: ?

Single ventricle cavity

Absent corpus callosum

* Presence frontal horns helps differentiate between Holoprosencephaly

What are the presenting symptoms of Ischemic Lesions: ?

Gastrointestinal bleeding

blood in the stools

vomiting of blood

Encephalopathy

What is Porencephalic?

Also known as porencephaly, is a cyst filled with cerebral spinal fluid. May be caused by hemorrhage , infarction, trauma, inflammation of the nervous system.

What is the sonographic appearance of Porencephalic?

Cyst without mass

Reduction of hemisphere

Midline shift

Contralateral ventricular enlargement

What is Hydranencephaly?

Brain development is destroyed and preplaced with cerebral spinal fluid. May be caused by bilateral occlusion of the internal carotid

What is the sonographic appearance of Hydranencephaly?

Midbrain, basal ganglia, choroid plexus, and thalamus sparing

Presence of cerebral spinal fluid

Absent Doppler flow in carotid

Possible absent falx cerebri

What is Congenital Hydrocephalus?

An imbalance of production and absorption of cerebral spinal fluid. There are three types: obstruction to outflow, decreased absorption, or rarely overproduction.

What is the sonographic appearance of Congenital Hydrocephalus?

Blunting of the lateral angles of the lateral ventricle

Widening of the ventricle system

Rare choroid plexus cyst

What are the presenting symptoms of Congenital Hydrocephalus?

enlargement of head, bulging fontanelles

What is Obstructive Hydrocephalus?

interference of cerebral flow

What is the sonographic appearance of Obstructive Hydrocephalus?

Enlargement of proximal ventricle cavity

What is Communicating Hydrocephalus?

pathway of cerebral fluid are open but there is a decrease in absorption. The ventricular system becomes uniformly distended. The most common cause is aquaduct stenosis.

What is the sonographic appearance of Communicating Hydrocephalus?

Narrow aqueduct of Slyvius may be replaced by small network

Widening of lateral ventricles

Normal size 4^th ventricle

Small posterior fossa

Cerebellum displaced posteriorly

Absent cisterna magna

What is Subarachnoid Cysts?

lined by arachnoid tissue and contain cerebral spinal fluid.

What is the sonographic appearance of Subarachnoid Cysts?

Normal vermis (Not Dandy- Walker)

Sonolucent

Verify with color Doppler

Interhemispheric cysts

Suprasellar cysts

Cerebral convexity cysts

What is Choroid Plexus cysts?

A hepatic cyst is usually a solitary, non-parasitic cyst of the liver. solitary or multiple.

What is the sonographic appearance of Choroid Plexus cysts?

Common and single

Well-defined

Anechoic mass

Unilateral

Left larger than right

4 to 7 mm

*Rare Multiple cysts larger than 10 mm associated with trisomy 18

What is Subependymal cysts?

Discrete in the lining of the ventricle. Commonly the result of sequel of germinal matrix

What is the sonographic appearance of Subependymal cysts?

Smooth walled

Spherical

Located in lateral ventricle

What is Galenic Venous Malformation?

Dilation of the vein of Galen, caused by vascular malformation off the posterior cerebral.

What is the sonographic appearance of Galenic Venous Malformation?

Anechoic cystic

Between lateral ventricles

Calcification

Hydrocephaly with possible thrombus

What is Subependymal-Intraventricular Hemorrhages?

Most common hemorrhage in preterm, affecting 30 to 50% of infants born before 32 weeks. The most common site is the interthalmic groove. Can cause obstruction in the choroid plexus.

What is the sonographic appearance of Subependymal-Intraventricular Hemorrhages?

Fluid

Echogenic structure in white matter

Become cystic and are absorbed leaving cavity

What is Intraparenchymal Hemorrhages?

Complicate Subependymal hemorrhage, meaning brain tissue has been

What is Intracerebellar Hemorrhages?

Difficult to find in live infants. Primmary: intracerebellar, venous infarction, traumatic laceration – resulting from occipital diastasis, extension to the cerebellum of a large SHE-IVH

What is the sonographic appearance of Intracerebellar Hemorrhages?

Echogenic structures

Within the less echogenic cerebellar parenchyma

Become cystic with time leaving cavity lesions

What is Epidural Hemorrhages?

Better diagnosed with CT. located peripherally along the surface of the brain.

What is the sonographic appearance of Epidural Hemorrhages?

Nonechogenic spaces

Between the echogenic calvarium and the cortex

What are the presenting symptoms of Epidural Hemorrhages?

persistent

What is Periventricular Leukomalacia?

Also called Multifocal White Matter Necrosis, most common ischemic lesion in the immature brain. Highly echogenic areas in the white matter.

What is the sonographic appearance of Periventricular Leukomalacia?

echolucencies in white matter

What are the presenting symptoms of Periventricular Leukomalacia?

Associated with Cerebral Palsy

What is Focal Brain Necrosis?

occur within large arteries. Early on cause destruction of cerebral tissue and leave cavitary lesions. These lesions correspond to cerebral infarction.

What is the sonographic appearance of Focal Brain Necrosis?

Echogenic localized lesions

Sonolucencies appear after few days

What is Ventriculitis?

A common complication of purulent meningitis. This is probably caused by infection spreading to the choroid plexus. Stents and other objects placed the body can cause this infection. Can lead to hydrocephalon

What is the sonographic appearance of Ventriculitis?

Thin septations extending from lateral ventricles.

Septations thicken