by Dr Harshita Saxena.

1. Neonatal
neurosonography

2.  Cranial sonography (US) 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

3. Indications
 Premature infants - all <1500g or <32 weeks gestation
 Low APGAR score
 Neurologic changes
 Cranial dysmorphism
 Seizures
 Follow-up of hemorrhage and periventricular leucomalacia.

4. Advantages of Cranial Ultrasound
 Safe
 Bedside
 Reliable
 Early imaging
 Serial imaging:
Brain maturation
Evolution of lesions
 Inexpensive
 Suitable for screening

5. Aims of Neonatal 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

6.  High-frequency phased array transducer (5-8 MHz) with a small
footprint probe
 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)
Cranial USG Technique

7. Examination is preferably done through the cranial incubator opening. All aseptic precautions.
Care should be taken not to move the infant & Pressure over the anterior fontanelle is to be avoided, especially in a critically ill
premature neonate.

8. Mastoid and posterior fontanelle approaches are useful in the demonstration of a subtle intraventricular
bleed in the occipital horn and minor bleed in the brain stem and cerebellum.

9. Standard Views(Anterior Fontanel)
 Coronal Views(at least 6 standard planes)

10. Standard Coronal Planes

13. The third ventricle is often small and difficult to see, but can vary considerably in size.
The brainstem may be seen as a tree-like shape.

14. The choroid plexus fills the lateral ventricles in this view and is prominent in preterm infants.
The white matter around the lateral ventricles may appear quite echodense (bright) in this plane and
is sometimes called a "blush" or "flare".

16. Sagittal Views (at least 5 standard planes)

17. Mid Sagittal plane

18. Angled Parasagittal View:
The choroid tucks up in the caudothalamic groove in the floor of the lateral ventricle. It does not extend beyond
the caudothalamic grooves into the frontal horns .

19. Tangential Parasagittal View:
Further angulation of the transducer laterally results in a section lateral to the lateral ventricles.
The Sylvian fissure is the key landmark in this view.

20. Supplemental Acoustic Window

21. DOPPLER IMAGING
Doppler imaging of the circle of Willis and the region of vein of
Galen is an essential part of the assessment.

22.  Doppler Vascular Measurements:
 The vessels that are the easiest to access are
 the anterior cerebral artery (ACA), best seen through the anterior
fontanelle in the sagittal plane and
 the middle cerebral artery (MCA) best seen through the temporal
window in the axial plane.
 The Resistivity index (RI) :
PS – ED SV - DV
PS SV
 Where PS= peak systolic velocity and ED = end diastolic velocity.
 The normal range is about 0.65 - 0.90.
 Values below 0.5 or above 0.9 are abnormal.

23. Normal variants and pitfalls that mimics
pathologic abnormalities
 Immature sulcation in premature infants
 Persistent fetal fluid filled spaces
 Mega cisterna magna
 Asymmetric ventricular size
 Choroid plexus variants
 Periventricular cystic lesions
 Hyperechoic white matter pseudolesions or periventricular halo
 Lenticulostriate vasculopathy

24.  Immature sulcation
 Infants born before the 24th week possess a smooth cerebral cortex
exhibiting only the sylvian fissures.
 a diagnosis of lissencephaly should not be made in newborn younger
than 24 weeks’ gestational age

25.  Persistent fetal fluid filled spaces
 Persistent fetal fluid–filled spaces, a common finding in healthy
neonates, include the cavum septi pellucidi (CSP), cavum vergae, and
cavum veli interpositi.
 The CSP is the most anterior and the most common of the fetal fluid–
filled spaces.
 Persistent fetal fluid–filled spaces occasionally persist into adulthood
and are a normal variant of no significance

26.  Mega cisterna magna
 The typical cisterna magna is less than 8 mm in both the sagittal and axial
planes
 A mega cisterna magna measures greater than 8 mm and is seen in 1% of
postnatally imaged brains
 A mega cistern magna is a normal variant distinguished from an arachnoid cyst
by its lack of mass effect and from a DandyWalker malformation by the
presence of the cerebellar vermis

27.  Assymetric ventricles
 Normal ventricles measure less than 10 mm in transverse diameter, with
60% of full term and 30% of premature infants having ventricles smaller
than 2–3 mm
 Asymmetry between the sizes of the ventricles has been observed in
20–40% of infants

28.  Choroid Plexus Variants
 It does not extend past the caudothalamic grooves into the frontal horns or past the
ventricular atria into the occipital horns.
 Echogenic material anterior to the caudothalamic groove or in the dependent portions of
the occipital horns suggests germinal matrix and intraventricular hemorrhage
 Lobular or bulbous variants of the choroid plexus occur most frequently in the glomus
within the ventricular atria and lateral ventricles
 Choroid cysts smaller than 1 cm are incidentally noted in 1% of infants at autopsy

29. At prenatal US these cysts can be predictive of trisomy 18

30.  Periventricular Cystic Lesions
 Connatal (or subfrontal) cysts are seen most often during the
early postnatal period and may regress spontaneously
 The sonographic appearance includes bilateral symmetric cysts
located adjacent to the frontal horns, just anterior to the foramina of
Monro. The cysts frequently appear in multiples and take on a classic
appearance that has been likened to a string of pearls

31.  Hyperechoic White Matter Pseudolesion or
Periventricular Halo
 Hyperechoic white matter pseudolesions, or periventricular
halos, may appear as artifacts due to anisotropic effect
 Additional images obtained at a 90° angle resolve the
finding and prevent misinterpretation
 periventricular white matter pseudolesions and halos are
normally less echogenic than the adjacent choroid plexus

32.  Lenticulostriate Vasculopathy /Mineralizing
Vasculopathy
 nonspecific thickening of the lenticulostriate artery walls
secondary to a variety of pathologic conditions and
infections
 seen on sonography as unilateral or bilateral branching,
linear, or punctate increased echogenicity within the
thalami.

34. 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
 Image 4-7 days after birth
 90% of hemorrhages occur in first week of life
 Follow with weekly U/S to evaluate for hydrocephalus

35.  Grade I - Confined to germinal matrix
 Grade II - Intraventricular without ventricular dilatation
 Grade III - Intraventricular with ventricular dilatation
 Grade IV - Periventricular hemorrhagic infarction

36. Grade 1 hemorrhage is limited to the region of the caudothalamic groove,
usually less than a centimetre in size.

38. Secondary hydrocephalus occuring several days after a grade 2 bleed
should not be mislabeled as grade 3 hemorrhage

40. 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

41. 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.

42. Periventricular Leukomalacia (PVL) or
White Matter Necrosis (WMN)
 Affects the periventricular zones.
 watershed zone between deep and superficial vessels.
 Premature infants born at less than 33 weeks gestation (38%
PVL) and less than 1500 g birth weight (45% PVL).
 Causes:
 Ischemia
 Infection
 Vasculitis

43. DeVries classification of PVL grading on
ultrasound
 Grade I PVL: Prolonged periventricular flare present for 7 days
or more.
 Grade II PVL: Presence of small-localized fronto-parietal cysts.
 Grade III PVL: Extensive periventricular cystic lesion involving
occipital and fronto-parietal white matter.
 Grade IV PVL: Areas of extensive sub cortical cystic lesions.

44. 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.
Grade I PVL: Prolonged periventricular flare present for 7 days or more.
Grade II PVL: Presence of small-localized fronto-parietal cysts.
The echogenicity has resolved at the time of cyst formation.

45. PVL or WMN
Coronal and transverse images demonstrating PVL grade 4
Sagittal image demonstrating extensive
PVL grade 3
Grade III PVL: Extensive periventricular cystic lesion involving occipital and fronto-parietal white matter.
Grade IV PVL: Areas of extensive sub cortical cystic lesions.

46. LEFT: Initial examination shows flaring. RIGHT: Follow up one
month later shows normal periventricular white matter.

47. Hydrocephalus
 Enlargement of ventricles with increased
head circumference
 Sonographic Findings
 Blunted lateral angles of enlarged
lateral ventricles
 Possible interhemispheric fissure
rupture
 Thinned brain mantle
 Aqueductal Stenosis
 Most common cause of congenital
hydrocephalus
 Sonographic Findings
 Widening of lateral and 3rd ventricles
 Normal 4th ventricle
Ventriculomegaly
Mild 0.5-1.0 cm
Moderate 1.0-1.5 cm
Severe 1.5 cm

48. 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.

49. Vein of Galen Malformation
 Fistulous connection - cerebral arteries and midline prosencephalic
vein
 2 types:
 Choroidal - 90%, presents in neonate as CHF and intracranial bruit
 Mural - presents in infancy with developmental delay, seizures, and
hydrocephalus

50. Gray-scale and Doppler coronal USG demonstrating
a cystic midline structure in the region posterior to third
ventricle with mass effect.
Typical swirl effect is noted on Doppler

51. Chiari II Malformation
 Batwing configuration of frontal horns
 Small posterior fossa with low-lying tentorium
 Interdigitating gyri
 Large massa intermedia
 Absence of corpus callosum
 Hydrocephalus
 Nearly 100% have myelomeningocele

55. Dandy Walker Malformation
 Posterior fossa cyst which communicates with 4th ventricle (arachnoid
cyst and enlarged foramen magnum do not)
 Large posterior fossa
 Hypoplastic cerebellar vermis and laterally displaced cerebellar
hemispheres
 Frequently associated with other anomalies

58. Temporal lobe arachnoid cyst
 Most common intracranial congenital cystic lesion
 Can have mass effect and bony remodeling
 Same appearance as CSF on all imaging modalities

60. Holoprosencephaly
Alobar Holoprosencephaly Semilobar Holoprosencephaly

61. Semilobar Holoprosencephaly
 Hypoplastic falx and interhemispheric fissure
 Partially separated thalamus
 Intermediate in severity between alobar and lobar holoprosencephaly
 Can have associated facial anomaly

65. Lissencephaly
 Lack of gyration and sulcation
 Thickened cortex
 Colpocephaly
 Homogeneous or “pseudoliver” appearance to the brain parenchyma
 “Figure eight appearance” due to shallow sylvian fissures
 Can result from intrauterine infection

68. 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
 Probst bundles impress upon lateral ventricles

72. References
 Bhat V, Bhat V. Neonatal neurosonography: A pictorial essay. Indian J
Radiol Imaging. 2014 Oct;24(4):389-400.
 Lowe LH, Bailey Z. State-of-the-Art Cranial Sonography: Part 1, Modern
Techniques and Image Interpretation. AJR Am J
Roentgenol. 2011;196:1028–33.
 De Vries LS, Eken P, Dubowitz LM. The spectrum of leukomalacia using
cranial ultrasound. Behav Brain Res 1992;49:1-6.