DR. Muhammad Bin ZulfiqarPGR II FCPS RADIOLOGY SIMS/SHL

• Aims• Indications• Sonographic technique• Sonographic Anatomy• Doppler• Pathologies

– Hemorrhage– PVL

Advantages of Cranial USG• Safe• Bedside- compatible• Reliable• Early imaging• Serial imaging:

Brain maturationEvolution of lesions

• Inexpensive• Suitable for screening

Aims of Cranial Ultrasound

• Exclude/demonstrate cerebral pathology• Assess timing of injury• Assess neurological prognosis• Help make decisions on continuation of

neonatal intensive care• Optimize treatment and support

Indications for Sonographic Exam

Cranial abnormality found on pre-natal sonogram Increasing head circumference with or without

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

Anatomy of the Neonatal Skull

Fontanelles (“Soft Spots”) Spaces between bones of the skull

Sonographic Technique

What anatomy do you scan?Supratentorial Compartment

Both cerebral hemispheres Basal Ganglia Lateral & 3rd Ventricle Interhemispheric fissure Subarachnoid spaces

Views Coronal Modified Coronal (anterior fontanelle) Sagittal (anterior fontanelle) Parasagittal (anterior fontanelle)

Sonographic Technique

Infratentorial Compartment Cerebellum Brain Stem 4th Ventricle Basal Cisterns

Views Coronal (mastoid fontanelle and

occipitotemporal area) Modified Coronal Sagittal Parasagittal (with increased focal depth &

decreased frequency)

• Transducers : 5–7.5–10 MHz• Appropriately sized• Standard examination: use 7.5–8 MHz• Tiny infant and/or superficial structures: use

additional higher frequency (10 MHz)• Large infant, thick hair, and/or deep structures:

use additional lower frequency (5 MHz)

The Acoustic Windows

Anterior FontanelThe Standard view window

Posterior FontanelSupplementary view window

Mastoid FontanelSupplementary view window

TemporalSupplementary view window

Standard Views….Anterior Frontal

• Coronal Views (at least 6 standard planes)

Standard Coronal Planes

First Coronal plane….Frontal Lobes

1. Interhemispheric

fissure

2. Frontal lobe

3. Skull

4. Orbit

Second Coronal Plane….Frontal horns of Lateral Ventricle

2.Frontal lobe

5.Frontal horn of lateral

ventricle

6.Caudate nucleus

7.Basal ganglia

8.Temporal lobe

9.Sylvian fissure

Third Coronal plane ….Foramen of Monro & 3rd Ventricle

2. Frontal lobe5. Frontal horn of lateralventricle6. Caudate nucleus

8.Temporal lobe

9.Sylvian fissure10. Corpus callosum11. Cavum septum pellucidum12. Third ventricle13. Cingulate sulcus

Fourth coronal plane…. body of the lateral ventricle

1.Interhemispheric fissure

8.Temporal lobe

9.Sylvian fissure

14.Body of lateral ventricle

15.Choroid plexus

16.Thalamus

17.Hippocampal fissure

18.Aqueduct of Sylvius

19.Brain stem

20.Parietal lobe

Fifth Coronal plane….Trigone of Lateral Ventricle

8.Temporal lobe10.Corpus callosum15.Choroid plexus20.Parietal lobe21.Trigone of lateral ventricle22.Cerebellum(a: hemispheres; b:

vermis)23.Tentorium24.Mesencephalon

Sixth Coronal Plane….Parieto Occipital Lobe

20.Parietal lobe

25.Occipital lobe

26.Parieto-occipital fissure

27.Calcarine fissure

• Sagittal Views (at least 5 standard planes)

Standard Views…..Anterior Fontanelle

Midsagittal plane….3rd and 4th ventricles

10.Corpus callosum11.Cavum septum pellucidum12.Third ventricle13.Cingulate sulcus16.Thalamus22b.Cerebellum(vermis)24.Mesencephalon26.Parieto-occipital fissure27.Calcarine fissure28.Pons29.Medulla oblongata31. Cisterna magna32. Cisterna quadrigemina33. Interpeduncular fossa34. Fornix

Second and Fourth Parasagittal planes….right and left lateral ventricles

2. Frontal lobe

5. Frontal horn of lateral ventricle

6. Caudate nucleus

8. Temporal lobe

14. Body of lateral ventricle

15. Choroid plexus

16. Thalamus

17. Hippocampal fissure

20. Parietal lobe

21. Trigone of lateral ventricle

22a. Cerebellum(hemisphere)

25. Occipital lobe

36. Occipital horn of lateral

ventricle

Black arrow indicates Caudothalamic groove

First & Fifth Parasagittal planes….Insula

2. Frontal lobe

8. Temporal lobe

9. Sylvian fissure

20. Parietal lobe

25. Occipital lobe

37. Insula

Supplemental Acoustic Window

Coronal view, using the PF as an acoustic window

8. Temporal lobe22. Cerebellum(a:

hemispheres; b: vermis)23. Tentorium25. Occipital lobe27. Calcarine fissure29. Medulla oblongata36. Occipital horn of lateral

ventricle38. Falx

Parasagittal view using PF as an acoustic window

8. Temporal lobe15. Choroid plexus16. Thalamus20. Parietal lobe21. Trigone of lateral

ventricle22a. Cerebellum

(hemispheres)25. Occipital lobe27. Calcarine fissure

Upper Transverse view using left Temporal window

Upper Transverse view using left Temporal window

1. Interhemispheric fissure8. Temporal lobe12. Third ventricle22. Cerebellum(a: hemispheres; b: vermis)23. Tentorium24. Mesencephalon33. Interpeduncular fossa41. Circle of Willis

Lower Transverse view using Left Temporal Window

• 8. Temporal lobe

• 22. Cerebellum(a: hemispheres; b: vermis)

• 25. Occipital lobe• 28. Pons• 41. Circle of Willis• 42. Prepontine cistern

Coronal View…..Mastoid Fontanelle

• 22. Cerebellum

– a: hemispheres

– b: vermis

• 28. Pons

• 30. Fourth ventricle

• 31.Interpeduncular Fossa

Transverse View….Mastoid Fontanelle

• 8. Temporal lobe

• 22. Cerebellum

– (a: hemispheres; b: vermis)

• 25. Occipital lobe

• 28. Pons

Doppler uses

Typical transcranial Doppler with imaging scan and recording from middle cerebral artery (MCA).

Doppler image shows circle of Willis. A = anterior cerebral artery M = middle cerebral artery P = posterior cerebral artery RI = resistive index

Demonstrates Decreased blood

flow/ischemia/infarction Vascular abnormalities Cerebral Edema Hydrocephalus Intracranial Tumors Near-field structures

BLOOD FLOW VELOCITY

• Changes in flow velocity occur when:

• There is a change in vessel caliber• There is a change in volume flow

should we do doppler study

vein of galen aneurysm

Hemorrhagic Pathology

Risk Factors Pre term infants Less than 1500 grams birth weight

Grading

Grade I - Confined to germinal matrix

Grade II - Intraventricular without ventricular dilatation

Grade III - Intraventricular with ventricular dilatation

Grade IV - Periventricular hemorrhagic infarction

Germinal Matrix Hemorrhage

Far more common in premature infants Germinal matrix - highly vascular and

vulnerable to hypoxemia and ischemia, only present 24-32nd week gestation more common site

Image 4-7 days after birth 90% of hemorrhages occur in first week of life Follow with weekly U/S to evaluate for

hydrocephalus

Subependymal-Intraventricular Hemorrhage (SEH-IVH)

Caused by capillary bleeding in the germinal matrix Continued subependymal (SEH) bleeding pushes into the

ventricular cavity (IVH) & continues to follow CSF pathways causing obstruction

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

Grade I Hemorrhage

Grade II Hemorrhage

Grade III Hemorrhage

Grade IV Hemorrhage

Intraparenchymal Hemorrhage Brain parenchyma destroyed Originally considered an

extension of IVH, but may actually be a primary infarction of the periventricular and sub cortical 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

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.

an echogenic layer of clotted blood (arrow) is seen between

the cortex and the skull.

five hours after the image the clot has started to lyse, and the layer is

now hypoechoic.

a parasagittal view demonstrates the fluid around the cortical mantle and the paucity of gyri due to the prematurity.

Periventricular Leukomalacia (PVL) or White Matter Necrosis (WMN)

Also known as Hypoxic-Ischemic Encephalopathy (HIE).

Affects the periventricular zones. watershed zone between deep and superficial

vessels.

Causes: Ischemia Infection Vasculitis

Periventricular Leukomalacia (PVL) or White Matter Necrosis (WMN) PVL presents as areas of increased periventricular

echogenicity.

Premature infants born at less than 33 weeks gestation (38% PVL) and less than 1500 g birth weight (45% PVL).

Effects

cerebral palsy, intellectual impairment visual disturbances

Periventricular Leukomalacia (PVL) or White Matter Necrosis (WMN)

Grade 1. Persisting more than 7 days

Grade 2. Developing into small periventricular cysts

Grade 3. Developing into extensive periventricular cysts, occipital and frontoparietal

Grade 4. In deep white matter developing into extensive subcortical cysts

PVL or WMN 1

2

Sagittal image of a child with PVL grade 1

Transverse and sagittal image of a child with PVL grade 2.

PVL or WMN

Coronal and transverse images demonstrating PVL grade 4

Sagittal image demonstrating extensive PVL grade 3

THANX

Chiari Malformation Sonographic Features

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.

Alobar Holoprosencephaly (Most Severe) Fused thalami anteriorly to a fused choroid plexus Single midline ventricle No falx cerebrum, corpus callosum, Interhemispheric

fissure, or 3rd ventricle

Semilobar Holoprosencephaly Single ventricle Presents with portions of the falx and Interhemispheric

fissure Thalami partially separated 3rd Ventricle is rudimentary Mild facial anomalies

Lobar Holoprosencephaly (Least Severe) Near complete separation of hemispheres; 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 Communicating Non-communicating Result of cerebral atrophy

Sonographic Findings 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 interhemispheric 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 Widening of lateral and 3rd ventricles Normal 4th ventricle

Hydrancephaly

Occlusion of internal carotid arteries resulting in necrosis of cerebral hemispheres Absence of both cerebral

hemispheres with presence of the falx, thalamus, cerebellum, brain stem, and positions of the occipital and temporal lobes

Sonographic findingsFluid filled cranial vault Intact cerebellum and

midbrain

Cephalocele

Herniation of a portion of the neural tube through a defect in the skull

Sonographic Findings Sac/pouch containing brain tissue and/or CSF and

meninges Lateral Ventricle Enlargement

Arachnoid Cysts

Cysts lined with arachnoid tissue and containing CSF

Causes Entrapment during embryogenesis Residual subdural hematoma Fluid extravasation secondary to

meningeal tear or ventricular rupture

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

meningitisSonographic Findings

Thin septations extending from the walls of the lateral ventricles.