1. Anatomy of the Cerebral Ventricles
Francois du Toit
Diagnostic Radiology
Kimberley Hospital

2. The Cerebral Ventricles
Fluid filled (CSF) spaces within the brain
2 Lateral ventricles in each hemisphere
3rd ventricle, Cerebral Aquaduct, 4th ventricle midline
Ependyma (thin epithelial membrane lining)

3. The Cerebral Ventricles

4. THE LATERAL VENTRICLE

5. The Lateral Ventricles
Lies within each cerebral hemisphere:
Frontal Horn (anterior)
Body (atrium)
Temporal Horn (inferior)
Occipital Horn (posterior)
Interventricular Foramen (of Monroe)
connects each lateral ventricle with the 3rd ventricle
at junction of anterior horn & body

6. The Lateral Ventricles

7. The Lateral Ventricles

8. THE LATERAL VENTRICLE
FRONTAL HORN

9. Frontal (anterior) Horn
Extends into frontal lobe
Roof & Ant extremity formed by:
Corpus Collosum (Rostrum & Genu)
Tapetum
Floor & Lateral Wall
Caudate Nucleus
Medial Wall
Septum Pellucidum

11. Roof / Anterior Border

12. Roof / Anterior Border

13. Frontal (anterior) Horn
Extends into frontal lobe
Roof & Ant extremity formed by:
Corpus Collosum (Rostrum & Genu)
Tapetum
Floor & Lateral Wall
Caudate Nucleus
Medial Wall
Septum Pellucidum

14. Floor of Anterior Horn

15. Floor of Anterior Horn

16. Frontal (anterior) Horn
Extends into frontal lobe
Roof & Ant extremity formed by:
Corpus Collosum (Rostrum & Genu)
Tapetum
Floor & Lateral Wall
Caudate Nucleus
Medial Wall
Septum Pellucidum

17. Medial Wall of Anterior Horn

18. THE LATERAL VENTRICLE
BODY (atrium)

19. Body of Lateral Ventricle
In Parietal Lobe
Roof & Lateral Wall
Corpus Callosum
Tapetal Fibres
Medial wall
Septum Pellucidum
Floor (medial)
Thalamus
Floor (lateral)
Body of Caudate Nucleus
Thalamostriate vein in between
Body of Fornix lies above the thalamus
Between the fornix and the thalamus
Choroid plexus lies invaginated into the cavity of the ventricle in a groove - the choroidal fissure

20. Roof / Anterior Border

21. Body of Lateral Ventricle
In Parietal Lobe
Roof & Lat
Corpus Callosum
Tapetal Fibres
Medial wall
Septum Pellucidum
Floor (medial)
Thalamus
Floor (lateral)
Body of Caudate Nucleus
Thalamostriate vein in between
Body of Fornix lies above the thalamus
Between the fornix and the thalamus
Choroid plexus lies invaginated into the cavity of the ventricle in a groove - the choroidal fissure

22. Body of Lateral Ventricle
In Parietal Lobe
Roof & Lat
Corpus Callosum
Tapetal Fibres
Medial wall
Septum Pellucidum
Floor (medial)
Thalamus
Floor (lateral)
Body of Caudate Nucleus
Thalamostriate vein in between
Body of Fornix lies above the thalamus
Between the fornix and the thalamus
Choroid plexus lies invaginated into the cavity of the ventricle in a groove - the choroidal fissure

23. Body of Lateral Ventricle
Caudate Nucleus
Thalamus

24. The Lateral Ventricles

25. Body of Lateral Ventricle
In Parietal Lobe
Roof & Lat
Corpus Callosum
Tapetal Fibres
Medial wall
Septum Pellucidum
Floor (medial)
Thalamus
Floor (lateral)
Body of Caudate Nucleus
Thalamostriate vein in between
Body of Fornix lies above the thalamus
Between the fornix and the thalamus
Choroid plexus lies invaginated into the cavity of the ventricle in a groove - the choroidal fissure

26. The Lateral Ventricles
Body of Fornix
Choroid Plexus
Thalamus

27. THE LATERAL VENTRICLE
TEMPORAL HORN (inferior)

28. Temporal (inferior) Horn
Extends anteriorly into Temporal Lobe
Lateral wall
Fibres of Tapetum
Roof
Tail of Caudate Nucleus
Floor
Hippocampus
pes hippocampi anterior
crus of the fornix arising from this

29. Temporal Horn of Lateral Ventricle
Tapetum
Temporal Horn of Lateral Ventricle

30. Temporal (inferior) Horn
Extends anteriorly into Temporal Lobe
Lateral wall
Fibres of Tapetum
Roof
Tail of Caudate Nucleus
Floor
Hippocampus
pes hippocampi anterior
crus of the fornix arising from this

32. Temporal (inferior) Horn
Extends anteriorly into Temporal Lobe
Lateral wall
Fibres of Tapetum
Roof
Tail of Caudate Nucleus
Floor
Hippocampus
pes hippocampi anterior
crus of the fornix arising from this

33. Crus of Fornix
Hippocampus
Pes

35. THE LATERAL VENTRICLE
OCCIPITAL HORN (Posterior)

36. Occipital (posterior) Horn
Posterior Extension of Lateral ventricle
Extends into Occipital Lobe
Arises from trigone of lateral ventricle
posterior convexity of the body of the lateral ventricle
May be absent / poorly developed / extend the full depth
12% bilaterally well developed

37. THE CHOROID PLEXUS

38. Choroid Plexus of Lateral Ventricle
Responsible for most of the production of CSF
Extends from Inferior horn, through body, to interventricular foramen
NO CHOROID PLEXUS in Occipital & Frontal Horn
Continuous with Choroid Plexus of 3rd ventricle
Invaginated into Lateral Ventricles medially (Choroidal Fissure)

39. Choroid Plexus of Lateral Ventricle

40. Choroid Plexus of Lateral Ventricle
Blood supply:
Ant Choroidal a. (Branch of ICA)
Post Choroidal a. (Branch of post Cerebral a.)
Venous drainage:
Sup Choroidal vein (begins at inferior horn and passes anteriorly to IV foramen)
Joins Sup Thalamostriate v. to form Internal Cerebral vein at IV foramen

42. 3rd Ventricle Slit-like space between Thalami
Width = 2-10mm (increasing with age)
Thin anterior wall – Lamina Terminalis between ant commissure (above) to optic chiasm (below)
Extension inferiorly into optic chiasm = supraoptic recess
Floor = Structures of hypothalamus including pituitary whose hollow stalk is the infundibular recess of the ventricle
Fold of Pia containing CP = Tela Choroidea
Narrow Anterior Apex at IV Foramen
Wider Posterior
If Fluid accumulates = Cavum Velum Interpositum

43. Thalamus
Third Ventricle

44. 3rd Ventricle Slit-like space between Thalami
Width = 2-10mm (increasing with age)
Thin anterior wall – Lamina Terminalis between ant commissure (above) to optic chiasm (below)
Extension inferiorly into optic chiasm = supraoptic recess
Floor = Structures of hypothalamus including pituitary whose hollow stalk is the infundibular recess of the ventricle
Fold of Pia containing CP = Tela Choroidea
Narrow Anterior Apex at IV Foramen
Wider Posterior
If Fluid accumulates = Cavum Velum Interpositum

45. Anterior Commisure
Lamina Terminalis
Optic Chiasm

46. 3rd Ventricle Slit-like space between Thalami
Width = 2-10mm (increasing with age)
Thin anterior wall – Lamina Terminalis between ant commissure (above) to optic chiasm (below)
Extension inferiorly into optic chiasm = supraoptic recess
Floor = Structures of hypothalamus including pituitary whose hollow stalk is the infundibular recess of the ventricle
Fold of Pia containing CP = Tela Choroidea
Narrow Anterior Apex at IV Foramen
Wider Posterior
If Fluid accumulates = Cavum Velum Interpositum

48. 3rd Ventricle Slit-like space between Thalami
Width = 2-10mm (increasing with age)
Thin anterior wall – Lamina Terminalis between ant commissure (above) to optic chiasm (below)
Extension inferiorly into optic chiasm = supraoptic recess
Floor = Structures of hypothalamus including pituitary whose hollow stalk is the infundibular recess of the ventricle
Fold of Pia containing CP = Tela Choroidea
Narrow Anterior Apex at IV Foramen
Wider Posterior
If Fluid accumulates = Cavum Velum Interpositum

50. 3rd Ventricle Slit-like space between Thalami
Width = 2-10mm (increasing with age)
Thin anterior wall – Lamina Terminalis between ant commissure (above) to optic chiasm (below)
Extension inferiorly into optic chiasm = supraoptic recess
Floor = Structures of hypothalamus including pituitary whose hollow stalk is the infundibular recess of the ventricle
Fold of Pia containing CP = Tela Choroidea
Narrow Anterior Apex at IV Foramen
Wider Posterior
If Fluid accumulates = Cavum Velum Interpositum

51. Cavum Velum Interpositum

52. 3rd Ventricle
Posteriorly - extends as small pineal recess into pineal stalk, and above this into suprapineal recess
Roof - anteriorly, the anterior commissure, column of fornix and IV foramen. Behind this the body of the fornix, with Choroid plexus invaginating below the fornix
60% of people - thalami connected across the ventricle via massa intermedia (non-neural connection)

54. 3rd Ventricle
Posteriorly - extends as small pineal recess into pineal stalk, and above this into suprapineal recess
Roof - anteriorly, the anterior commissure, column of fornix and IV foramen. Behind this the body of the fornix, with Choroid plexus invaginating below the fornix
60% of people - thalami connected across the ventricle via massa intermedia (non-neural connection)

55. Fornix
Choroid Plexus
Ant Commisure

56. 3rd Ventricle
Posteriorly - extends as small pineal recess into pineal stalk, and above this into suprapineal recess
Roof - anteriorly, the anterior commissure, column of fornix and IV foramen. Behind this the body of the fornix, with Choroid plexus invaginating below the fornix
60% of people - thalami connected across the ventricle via massa intermedia (non-neural connection)

57. THE CEREBRAL AQUEDUCT

58. Cerebral Aquaduct
Narrow channel connecting post end of 3rd ventricle with sup end of 4th ventricle
1.5cm in length. 1-2mm in diameter
Passes through Brainstem with Tectum posterior to it and Tegmentum and Cerebral Peduncles anteriorly
Nuclei of CN III,IV,V surround aqueduct and are called the periaqueductal grey matter

59. Cerebral Aqueduct

62. 4th Ventricle Aqueduct widens Posterior to the Pons
Narrows again in inferior part of medulla as central canal of the medulla & of spinal cord
Floor = diamond shaped (rhomboid fossa) Formed by post surface of pons and upper part of medulla
Roof
SUPERIOR superior cerebellar peduncle with sup medullary velum between INFERIOR inf cerebellar peduncle and the inf medullary velum Over these lies the cerebellum

63. 4th Ventricle

64. 4th Ventricle

65. 4th Ventricle Aqueduct widens Posterior to the Pons
Narrows again in inferior part of medulla as central canal of the medulla & of spinal cord
Floor = diamond shaped (rhomboid fossa) Formed by post surface of pons and upper part of medulla
Roof
SUPERIOR superior cerebellar peduncle with sup medullary velum between INFERIOR inf cerebellar peduncle and the inf medullary velum Over these lies the cerebellum

66. 4th Ventricle Roof

67. 4th Ventricle
Foramina

68. Foramina of 4th Ventricle
3 Openings in lower part of roof
one median aperture (of Magendie)
large opening in inf medullary velum beneath the cerebellum, which communicates with the cisterna magna
two lateral apertures (of Luschka)
at apex of lateral recesses of the ventricle
open anteriorly just behind CN VIII into the pontine cistern
Choroid plexus invaginates the lower part of its roof and is supplied by inferior cerebellar a.

69. Foramen of Magendie

70. 4th Ventricle Foramina 3 Openings in lower part of roof
one median aperture (of Magendie)
large opening in inf medullary velum beneath the cerebellum, which communicates with the cisterna magna
two lateral apertures (of Luschka)
at apex of lateral recesses of the ventricle
open anteriorly just behind CN VIII into the pontine cistern
Choroid plexus invaginates the lower part of its roof and is supplied by inferior cerebellar a.

71. Foramen of Luschka

72. 4th Ventricle Foramina 3 Openings in lower part of roof
one median aperture (of Magendie)
large opening in inf medullary velum beneath the cerebellum, which communicates with the cisterna magna
two lateral apertures (of Luschka)
at apex of lateral recesses of the ventricle
open anteriorly just behind CN VIII into the pontine cistern
Choroid plexus invaginates the lower part of its roof and is supplied by inferior cerebellar a.

73. Choroid Plexus of 4th Ventricle

74. CSF PRODUCTION & FLOW

75. CSF Production & Flow
Total Volume of CSF = 150ml (25ml is within and around the spinal cord)
Produced at 0.4ml/min
Production independent of CSF pressure
Principally produced by Choroid Plexus of lateral ventricles

76. CSF Flow Flows through Interventricular foramen into 3rd ventricle
Via Cerebral Aqueduct to 4th Ventricle
Via Midline Aperture (of Magendie) into Cisterna Magna
Via Lateral Apertures into Pontine Cistern
From Basal Cisterns
some fluid flows down and bathes the spinal cord
The Remainder
passes upward through tentorial hiatus and diffuses over surface of the cerebral hemispheres

77. CSF Flow

78. Into 3rd Ventricle (Monroe)

79. Into 4th Venticle (Cerebral Aqueduct)

80. Into Cisterna Magna (Magendie)

81. Down to Spinal Cord

82. Upwards over Cerebral Hemispheres

83. CSF Absorbtion CSF is absorbed through the Arachnoid Villi
herniations of arachnoid through holes in the dura into venous sinuses
most numerous in sup sagittal sinus
discrete in children
with age they aggregate into visible clumps called arachnoid granulations
these indent the inner table of the skull beside the dural venous sinuses

84. Arachnoid Villi

85. CSF Absorbtion
1/3 CSF absorbed along similar spinal villi OR escapes along nerve sheaths into perineural lymphatics
This absorption is passive and dependent on hydrostatic pressure differences

86. ANATOMICAL VARIANTS

87. Cavum Velum Interpositum
Fluid Collects in Tela Choroidea
Narrow apex anterior
Wider Posteriorly

88. Cavum Velum Interpositum

89. Cavum Septum Pellucidum
Two potential spaces between leaflets of Septum Pellucidum
ANTERIOR Cavum Septum Pellucidum
POSTERIOR Cavum Vergae
Obliterate Postero-anteriorly during development
CSP present in 100% of fetusses
85% Obliterate by 3-6months
Absent CSP in fetus associated with significant CNS abnormalities

90. Cavum Vergae Seperation of the leaflets of septum pellucidum
Posterior extension to the splenium of corpus collosum
Because of ordered obliteration – CSP almost always accompanies a Cavum Vergae

91. Cavum Septum Pellucidum
Cavum Vergae
Cavum Septum Pellucidum
Cavum Vergae

92. References
Anatomy for Diagnostic Imaging, 3rd Edition Stephanie Ryan, Michelle McNicholas, Stephen Eustace
Atlas of Human Anatomy, 2nd Edition Frank H. Netter