cranial ultrasnography, by dr rabab hashem

Basics of neonatal

cranial US

ByDr: Rabab Hashim

Cranial sonography is the most widely used neuroimaging procedure in premature infants.

US helps in assessing the neurologic status of the child, since clinical examination and symptoms are often nonspecific

It gives information about immediate and long term prognosis.

Advantages of Cranial Ultrasonography

SafeBedsideReliableEarly imagingSerial imaging:

Brain maturationEvolution of lesions

InexpensiveSuitable for screening

Equipment

What is the optimum time for CUS

How images are assessed by cranial US?

Anatomy

Maturation

Distinction of cortex/white matter

Echogenicity/homogeneity of white matter

Ventricular system: size, lining, and if dilated to

perform serial measurements

Midline shift

Performing Cranial Ultrasound Examinations

Preterm neonates and sick full-term neonates are

examined in their incubator while maintaining monitoring.

performed while only the incubator windows are open

Manipulation of the infant (with the exception of minor

adjustments) is rarely necessary while scanning

through the anterior fontanel.

Older infants and full-term neonates can be examined in

their cot or car seat or on an adult’s lap.

Anatomical points

Ventricular SystemLateral Ventricles:

Largest of the CSF cavities.Frontal HornBodyOccipital HornTemporal Horn

Trigone “Atrium”Foramen of Monro

3rd VentricleAqueduct of Sylvius

4th VentricleForamen of LuschkaForamen of

Megendie

Anterior FontanelThe Standard view window

Posterior FontanelSupplementary view window

Mastoid FontanelSupplementary view window

TemporalSupplementary view window

Standard ViewsAllow optimal visualisation of the supratentorial structures.

the anterior fontanel is used as the acoustic window.

Images are recorded in 6 coronal and 5 sagittal planes.

In addition to the standard planes, the whole brain can be

scanned to obtain an overview of the brain’s appearance.

This allows assessment of the anatomical structures and

detection of subtle changes and small and/or superficially

located lesions.

Coronal PlanesThe anterior fontanel is palpated, and the transducer

is positioned in the middle, with the marker on the

probe turned to the right side of the baby

The probe is angled sufficiently far forwards and

backwards to scan the entire brain from the frontal

lobes at the level of the orbits to the occipital lobes

Well-fitting ultrasound probe, positioned on the anterior fontanel. Arrowindicates the marker on the probe

Sagittal PlanesThe transducer in the middle of the anterior fontanel.

the marker is now pointing towards the baby’s mid-face.

The anterior part of the brain will thus be projected on

the left side of the monitor

First, a good view of the midline is obtained.

The transducer is subsequently angled sufficiently to the

right and the left to scan out to the Sylvian fissures on

both sides.

Probe positioning for obtaining sagittal planes. Arrow indicates marker

Normal CUS Scan

Coronal Planes

Coronal Views

1st coronal plane at the level of the frontal lobe

Anterior horns of the lateral Ventricles

The Third Ventricle

Post cronal(Trigone)

Sagittal Views

Midline Sagittal

Lateral (RT &LT)Angled Parasagittal

Normal variant

Cavum septum pellcidum

Chorioïd plexus cyst

Abnormal Scans

Congenital infectDWV&VOGV

PVLPHVDIVH

Intraventricular Haemorrhage

More common in premature infants

Germinal matrix - highly vascular and

vulnerable to hypoxemia and ischemia.

Image 4-7 days after birth

90% of hemorrhages occur in first week of life

Follow with weekly U/S to evaluate for

hydrocephalus

IVH grading

Grade I - Confined to germinal matrix

Grade II - Intraventricular without

ventricular dilatation

Grade III - Intraventricular with ventricular

dilatation

Grade IV - Periventricular hge and

hemorrhagic infarction

Germinal matrix haemorrhage

G1 IVH

G1 IVH

IVH GII

IVH III

IVH III

Post Hemorrhagic hydrocephalus

PHVD

PHVD

PHH

Ventricular index

Ventricular index and HC chart(Levene)

Ventricular reservoir

Periventricular Leukomalacia (PVL)5-10% of premature infants Infarction of deep white matter Seen as increased echogenicity (greater than choroid

plexus)Often missed with ultrasound, serial exams increase

sensitivity( grade I) May get cystic changes in 2-3 weeks Symptoms: spastic diplegia, intellectual deficits

Periventricular Leukomalacia(PVL)

Periventricular Leukomalacia G I

PVL II

Periventricular Leukomalacia G II

Periventricular Leukomalacia G III

PVL IV

Periventricular Leukomalacia G IV

Congenital malformation

Dandy-Walker Variant

Posterior fossa cyst which communicates with 4th ventricle

Large posterior fossa Hypoplastic cerebellar

vermis and laterally displaced cerebellar hemispheres

Frequently associated with other anomalies

Vein of Galen Malfomatiorn

Congenital infection

Calcifications

Congenital Absence of the Corpus Callosum

80% have associated anomalies

Parallel lateral ventricles

Elevated 3rd ventricle Absent cingulate

gyrus and sulcus “Sunburst sign” -

radially arranged sulci

Our patient

Limitations of Cranial Ultrasonography

Image quality can be affected by small acoustic windows, thick hair or

hats used for ventilatory support systems

Brain’s convexity is not well visualized, cortical infarctions may be

overlooked, especially in the first days after the event.

extracerebral haemorrhage located at the convexity of the cerebral

hemispheres (subdural, epidural, and subarachnoid haemorrhages not be

reliably assessed)

Hypoglycaemic parenchymal injury, often involving the occipital lobes,

may not be recognized.

Some lesions resulting from infection, such as (micro-) abscesses and

encephalitis, may not be recognized by cUS.

Take home message cUS plays an important role in predicting neurological prognosis in

the high-risk newborn.

Standard cUS is performed using the anterior fontanel.

Optimal timing and frequency of serial cUS examinations is essential

in the high-risk neonate ischaemic lesions may develop at any time

during the neonatal period and may change in appearance over a

variable period of time.

MRI is recommended in the case of (suspected) parenchymal brain

injury and in very preterm neonates, neonates with neurological

symptoms, congenital malformations and miscellaneous disorders.