Cranial ultrasnography, by dr Rabab hashem
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Transcript of 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 <)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.