1. Neurosonography of the Neonatal Brain
Abnormalities
Holdorf

2. Congenital Brain Malformations
Disorders of Organogenesis
Disorders of Neural Tube Closure
Disorders of Diverticulation and Cleavage
Disorders of Sulcation/Cellular Migration
Destructive Lesions
Hydrocephalus
Infection – Congenital/Acquired
Intracranial masses – Brain Tumors/Cystic Lesions

3. Disorders of Organogenesis
Four stages of organogenesis
Neural tube formation - occurs 3-4 weeks gestation
Segmentation and diverticulation – occurs 5-6 weeks gestation; forebrain divides; formation of olfactory bulbs, optic vessels and face development
Neuronal Proliferation and Migration – occurs weeks gestation; cells proliferate and migrate and organize into functional structures
Myelination – occurs from 2nd trimester

4. Chiari Malformations
Chiari I – downward displacement of cerebellar tonsils, without displacement of 4th ventricle or medulla ; most common
Chiari II – Of greatest clinical importance due to myelomeningocele; displacement of medulla and brainstem
Chiari III – the medulla, 4th vent and cerebellum are encased by a high encephalomeningocele

5. Chiari I

6. Chiari II Sonographic findings
Batwing appearance – Anterior and inferior pointing frontal horns
Enlarged lateral ventricles, occipital horns larger than frontal horns (colpocephaly)
Slightly enlarged 3rd ventricle
displacement of pons, medulla and vermis
Non-visualized 4th vent due to compression
CSP is completely or partially absent
CC usually absent
May be hydrocephalus
Obliterated Cisterna Magna

7. Chiari II

8. Chiari II

9. Chiari II
Diagnosed usually in utero with sonography
MS-AFP 4

10. Chiari III
Cerebellum, 4th vent and medulla are contained within a cervical encephelomeningocele 5

11. Agenesis of Corpus Callosum
CC neural fibers that connect the two hemispheres of the cerebrum
Allows for communication
Development of CC occurs 8-20 weeks gestation
Usually associated with other anomalies

12. Agenesis of CC Sonographic Appearance Widely spaced ventricles
Narrow frontal horns
Absence of SP
Dilated and elevated third vent
Sulci are arranged radially – “sunburst sign”
Colpocephaly

13. Agenesis of Corpus Callosum

14. Agenesis of Corpus Callosum

15. Agenesis of Corpus Callosum

16. Lipoma of Corpus Callosum
May result from mal-development of neural crest tissues
Found in the interhemispheric fissure
Can be associated with agenesis of corpus callosum

17. Lipoma of Corpus Callosum

18. Dandy Walker Malformation
Dilated 4th ventricle that communicates with posterior fossa
Theories for its formation include
Agenesis of Foramen of Luschka and Magendie
Malformation of roof of 4th ventricle
Delayed opening of Foramen Magendie
70% associated with other CNS anomalies
Can also have chromosomal abnormalities and gastrointestinal, cardiac, MSK, etc., abnormalities

19. Dandy Walker Malformation
Sonographic findings
Enlarged 4th ventricle that connects with the cisterna magna
Large posterior fossa
Hypoplastic cerebellar vermis
Hypoplastic cerebellar hemispheres displaced laterally by fourth vent
May also have absent CC
May have hydrocephalus

20. Dandy Walker Malformation
Images of Dandy Walker Malformation

21. Disorders of Diverticulation and Cleavage
Holoprosencephaly – results from a failure of the prosencephalon to divide into the telencephalon and diencephalon between 4-8 weeks gestation
3 types
Alobar
Semi Lobar
Lobar

22. Holoprosencephaly Alobar Most severe
Characterized by cyclopia and/or hypotelorism with a proboscis above eyes
Single crescent shaped vent
Thin, fused cerebral cortex usually found in anterior portion of head
No falx, no interhemispheric fissure, no corpus callosum
Absent 3rd ventricle
Fused echogenic Choroid plexus
Fused thalami
Images

23. Holoprosencephaly Semi Lobar Single ventricle
More brain matter present
May see a small portion of falx and interhemispheric fissure in occipital lobe
Thalami partially separated
May have corpus callosum
Less severe facial abnormalities
Images

24. Holoprosencephaly Lobar Least severe
Almost complete separation of hemispheres
Falx and interhemispheric fissure are present but may be shallow anteriorly
Frontal lobes of cerebrum may be fused
Absent SP
Anterior horns of lateral ventricles are fused and square shaped by occipital horns are separate
Third ventricle is usually present
Separated thalami
Mild facial abnormalities
Images

25. Disorders of Sulcation
and Migration
Schizencephaly
Lissencephaly

26. Schizencephaly
Believed to be caused by neuronal migration malformation
Rare
Characterized by clefts within the cerebral hemispheres
May be unilateral or bilateral
May be closed or open

27. Schizencephaly
Open Lip – cleft through cortex and communicates with ventricle

28. Schizencephaly Open Lip
Cleft extends from ventricle to cortical surface of brain

29. Schizencephaly Closed Lip
Gray matter extending from pia mater to ventricle

30. Lissencephaly Abnormal migration of neurons Lack of sulci
Brain appears smooth

31. Cystic Encephamalacia
Destructive Lesions
Porencephalic Cyst
Hydranencephaly
Cystic Encephamalacia

32. Porencephalic Cyst Area within brain parenchyma filled with CSF
Results from brain destruction due to injury, illness, infection, stroke, gene mutations
Images - View.aspx?cat=506&case=2161

33. Hydranencephaly
Thought to be caused by bilateral occlusion of internal carotid arteries
May also result from other destructive processes
Involves almost complete destruction of cerebral cortex
Severest form of porencephaly

34. Hydranencephaly

35. Hydranencephaly

36. Cystic Encephalomalacia
Area of focal brain damage due to insult
Lesion typically does not communicate with ventricular system
Can be caused by infection, thrombus, hypotension, etc.
Appears as cystic areas with glial septations

37. Cystic Encephamalacia
Sonographic Appearance
Cystic areas containing CSF replace areas of cerebral hemispheres
Echogenic septations between cystic cavities

38. Hydrocephalus Abnormal accumulation of cerebrospinal fluid
Caused by one of the following
Obstruction to flow (IVOH or EVOH)
Decreased absorption
Increased production

39. Hydrocephalus CSF protects brain and spinal cord
Regulates chemical environment surrounding the brain
Supplies nutrients to nervous system tissue
Removes waste from from cerebral metabolism

40. Hydrocephalus Can be detected in utero by 15 weeks gestation
Detected with measurement of lateral ventricle
Atrium of lateral vent and glomus > 10mm
Evaluate the rest of CNS for abnormalities

41. Hydrocephalus
Intraventricular obstruction – flow obstructed within the ventricular system
Post hemorrhagic at Aqueduct or fourth ventricle
Posterior fossa subdural hematoma
Dandy Walker Malformation
Chiari II Malformation
Tumor or cyst

42. Hydrocephalus
Extraventricular Obstruction – flow obstructed outside the ventricle
Posthemorrhagic scarring
Postinfectious scarring
Venous obstruction
Absence or hypoplasia of arachnoid granulations

43. Hydrocephalus

44. Hydrocephalus

45. Hypoxic-Ishemic Events
Germinal Matrix Hemorrhage
Posterior Fossa Hemorrhage
Subarachnoid Hemorrhage
Periventricular Leukomalacia

46. Germinal Matrix Hemorrhage
Germinal Matrix – network of tiny blood vessels and primitive neural tissue located in the subependymal layer of the ventricular system
At birth small amount located at caudothalmic groove
Highly susceptible to pressure changes
Most bleeds occur between within first 7 days
Often occur after 1st day of life

47. Subependymal Hemorrhage
Grade I
Echogenic, homogeneous mass near caudothalmic groove
May appear as prominence in choroid plexus
Will become sonolucent with age
May completely resolve or result in subependymal cyst

48. Subependymal Hemorrhage

49. Intraventricular Hemorrhage
Grade II
Subependymal hemorrhage extends into the lateral ventricle without ventricular dilation
Hyperechoic clot can be seen in a portion of ventricle
Choroid plexus may appear asymmetric
Clot/choroid may be indistinguishable
As clot ages will become sonolucent
View.aspx?cat=501&case=4131

50. Intraventricular Hemorrhage with Hydrocephalus
Grade III
Clot extending into ventricle with hydrocephalus
The clot and choroid may become more defined
Variable degrees of hydrocephalus

51. Grade III

52. Posterior Fossa Hemorrhage
Can occur due to
4th ventricle germinal matrix
Traumatic delivery
Coagulopathy
ECMO Therapy
Mastoid fontanelle or MR evaluation for diagnosis

53. Intraparenchymal Hemorrhage
Grade IV
Extension of bleed into brain parenchyma
Usually in cerebral cortex]
Usually in frontal or parietal lobe
Acutely appears as echogenic, homogeneous area with cortex
Porencephaly will later develop
Images

54. Subarachnoid Hemorrhage
Sonographically can appear as
Enlarged interhemispheric fissure
Enlarged sylvan fissure
Thickened sulci
Increased echogenicity

55. Periventricular Leukomalacia
Infarction and necrosis of periventricular white matter
Usually occurs adjacent to the external angles of the lateral ventricles
Usually bilateral and are often symmetrical
Can be diffuse or focal

56. Periventricular Leukomalacia
Initial sonogram may be normal
Within 2 weeks, periventricular white matter increases in echogenicity
2-4 weeks, cystic changes develop; ventricles enlarge
Cysts can be single or multiple
Cystic areas may enlarge or resolve
Images -

57. Congenital Infection TORCH Toxoplasma gondii Other (i.e. syphilis)
Rubella
Cytomegalovirus
Herpes simplex virus

58. Congenital Infection CMV is most common (1% of all births)
Can be acquired at birth or after birth with little or no consequence
Prenatal CMV infections can cause serious damage
Toxoplasmosis caused by toxoplasma gondii is second most common
The earlier the infection, usually the worse the associated abnormalities

59. Congenital Infection Early infection can result in Microcephaly
Lissencephaly
Hypoplastic cerebellum
Polymicrogyria
Ventriculomegaly

60. Congenital Infection Infection can result in Death
Congenital malformations
Developmental delays
Mental deficiencies
Seizures

61. Congenital Infection
Sonographic Appearance of CMV and Toxoplasma gondii
Periventricular (CMV) or scattered cerebral calcifications (TP)
Echogenic foci with or without shadowing
Ventriculomegaly and/or intraventricular septations
Periventricular cysts
Echogenic vasculature

62. Congenital Infection
Herpes (HSV-2) can be acquired transplacentally or vaginal exposure
Cystic encephalomalacia of peri-ventricular white matter
Scattered calcifications
Rubella – extremely rare

63. Neonatal Acquired Infections
Meningitis – clinical diagnosis; imaging used to evaluate complications
Subdural fluid collections
Edema
Ventriculitis – complication of meningitis
Hydrocephalus
Echogenic debris within ventricle
Intraventricular septa formation

64. Intracranial Masses
Only 11% of children with brain neoplasms present before 2 years old
Tumors that present prior to that are usually congenital
Can be difficult to detect
Teratomas – most frequent neoplasms reported in the first year of life
Astrocytomas
Rhabdoid tumor
Ependymomas

65. Intracranial Masses Ultrasound appearance Usually evaluated with MRI
Variable
Nonspecific
Many are hyperechoic
Usually evaluated with MRI

66. Cystic Intracranial Lesions
Common
US is best method to evaluate these lesions
Arachnoid cysts – most common true cyst of the brain; CSF collects between a split arachnoid
Choroid Plexus cysts – usually single and not associated with other CNS abnormalities
Subependymal cysts - beneath ependymal lining of vents
Frontal Horn cyst – attached directly to frontal horn of lateral vent
Galenic Venous malformation - dilation of the Vein of Galen due of vascular malformation

67. Choroid Plexus Cyst

68. Subependymal Cysts

69. Frontal Horn Cyst

70. Vein of Galen Malformation

71. Vein of Galen Malformation

72. References
Image slide 5 Chiari 1 retrieved from on November 13, 2013
Image slide 7 Chiari II retrieved from
Image slide 8 Chiari II retrieved from on November 12, 2013
Image slide 9 Chiari II retrieved from on November 12, 2013
Image slide 11 Chiari III Encephalocele retrieved from on November 12, 2013
Image slide 13 Agenesis of CC retrieved from on November 13, 2013
Image slide 14 from retrieved from on November 13, 2013
Image slide 15 – Agenesis of CC retrieved from November 13, 2013
Image Slide 17 - Corpus Callosum Lipoma retrieved fromhttp:// 1.jpg on November 13, 2013
Image slide 20 – Dandy Walker Malformation retrieved from on November 13, 2013
Image Slide 27 – Schizencephaly retrieved from on November 13, 2013
Image slide 28 – Schizencephaly retrieved from on November 13, 2013
Image slide 29 – Schizencephaly retrieved from on November 13, 2013

73. References
Image slide 30 – Lissencephaly retrieved from on November 13, 2013
Image slide 34 Hydranencephaly retrieved from on November 13, 2013
Image slide 35 – Hydranencephaly retrieved from on November 13, 2013
Image slide 37 Cystic Encephelamalacia retrieved from f9700&sectionEid=4-u1.0-B on November 13, 2013
Image slide 43 Hydrocephalus retrieved from on November 13, 2013
Image slide 44 Hydrocephalus retrieved from on November 13, 2013
Image Slide 48 Grade 1 hemorrhage retrieved from November 13, 2013
Images slide 51 Grade 3 on November 13, 2013
Image slide 51 Grade 3 on November 13, 2013
mage slide 67 choroid Plexus Cyst -retrieved from on November 13, 2013
Image slide 68 Subependymal cyst - on November 13, 2013
Image slide 69 – Frontal Horn Cyst retrieved from on November 13, 2013
Image Slide 70 – Vein of Galen Malformation – retrieved from on November 13, 2013
Image slide 71 Vein of Galen Malformation retrieved from on November 13, 2013