Diagnostic Imaging of Intracranial Vascular malformations

1. C.N.S.
Vascular Malformations

2. Mohamed Zaitoun
Assistant Lecturer-Diagnostic Radiology
Department , Zagazig University Hospitals
Egypt
FINR (Fellowship of Interventional
Neuroradiology)-Switzerland
zaitoun82@gmail.com

5. Knowing as much as
possible about your enemy
precedes successful battle
and learning about the
disease process precedes
successful management

6. Vascular Malformations
(i) Malformations with AV shunts :
a) AVM
b) Dural AVF
c) Pial AVF
(ii) Malformations without AV shunts :
a) Cavernous Malformation
b) Venous Malformations
c) Capillary Telangiectasia
d) Moyamoya Disease

7. (i) Malformations with AV shunts :
a) AVM
b) Dural AVF
c) Pial AVF

8. a) Arteriovenous Malformations (AVM) :
1-Definition
2-Incidence
3-Clinical Picture
4-Types
5-Cerebrofacial Arterio-venous Metameric Syndrome
(CAMS)
6-Proliferative Angiopathy
7-Radiographic Features
8-Grading System
9-Complications
10-Treatment Options

9. 1-Definition :
-An AVM is a congenital high-flow vascular
malformation consisting of directly connecting
arteries & veins without an intervening
capillary bed
-The transition between artery and vein can
take place via a so-called nidus (i.e. a tangle of
abnormal vessels located in the brain
parenchyma)

10. 2-Incidence :
-Peak age is 20 to 40 years
-98% of AVM are solitary
-Occurs intra-axially & 85 % are supratentorial
-Multiple lesions in various syndromes, Osler-
Weber-Rendu and Wyburn-Mason

11. 3-Clinical Picture :
-One or combination of hemorrhage (usually
parenchymal hemorrhage, rarely
subarachnoid, 40 %), seizures (30 %),
neurological deficit or headache (20 %)
-Aneurysms of the feeding arteries or intra-nidal
arteries are often seen which predispose to
bleeding

12. 4-Types :
a) Parenchymal, 80% (ICA and vertebral artery
supply, congenital lesions)
b) Dural, 10% (ECA supply, mostly acquired
lesions)
c) Mixed, 10%

13. 5-Cerebrofacial Arterio-venous Metameric
Syndrome (CAMS) :
a) Definition
b) Types
c) Diagnosis

14. a) Definition :
-CAMS (also known as Wyburn-Mason
syndrome or Bonnet-Dechaume-Blanc
disease)

15. b) Types :
1-CAMS type 1 :
-Involves the medial prosencephalon and will
manifest with AVMs located at the corpus
callosum, hypothalamus (hypophysis) and nose
2-CAMS type 2 :
-Involves the lateral prosencephalon with AVMs at
the occipital lobe and optic tract including the
thalamus, retina and maxilla

16. CAMS type 2 in a 10-year-old girl who presented with a 1-year history of progressive right
hemiparesis , chemosis and proptosis of the left eye were also noted (a, b) CT+C obtained at
the level of the orbits (a) and brain (b) show an enhancing vascular lesion at the left basal
ganglia , the lesion exerts a mass effect on the left lateral ventricle , in addition , serpiginous
structures are seen surrounding the optic nerve , (c) Lateral LT ICA angiogram shows a
proliferative type brain AVM nidus at the basal ganglia , another smaller AVM is noted
surrounding the left optic nerve (solid arrow) , there is early venous drainage anteriorly into
the basal frontal cortical veins (arrowheads) and posteriorly into the basal vein of Rosenthal
(open arrow)

17. CAMS type 2 in a 7-year-old girl who presented with recurrent episodes of
bleeding from the gum due to eruption of a left molar , (a) Coronal CT
scan (bone window) reveals an osteolytic lesion within the alveolar ridge
of the left maxilla , (b, c) Left external (b) and internal (c) carotid
angiograms show a facial osseous AVM supplied by branches of the
internal maxillary and transverse facial arteries and draining into an
intraosseous venous pouch (arrow in b) , this finding corresponds to the
osteolytic lesion seen in a and proved to be the source of the patient’s
bleeding , an AVM of the left optic nerve is also noted, thereby allowing
the diagnosis of CAMS type 2

18. 3-CAMS type 3 :
-Involves the rhombencephalon and affected
patients will have AVMs at the cerebellum, pons
and mandible
c) Diagnosis :
-The most important clue to the diagnosis of CAMS
is the presence of multiple AVMs in both the
brain parenchyma and the facial region

20. 6-Proliferative Angiopathy :
a) Incidence
b) Clinical Picture
c) Radiographic Features

21. a) Incidence :
-Cerebral proliferative angiopathy, previously
known as diffuse nidus type AVM, is present in
an estimated 2%-4% of all brain AVMs
-There is a female predilection of 2:1 with a
rather young mean patient age (20 years)

22. b) Clinical Picture :
-Progressive neurologic deficits, transient
ischemic attacks, seizures and headaches are
the common presenting symptoms with
hemorrhage being extremely rare

23. c) Radiographic Features :
1-CT & MRI
2-Catheter Angiography

24. 1-CT & MRI :
-The typical MR imaging and CT findings include
a proliferative type nidus in which normal
brain parenchyma is interspersed between
the abnormal vessels
-Often an entire lobe or even brain hemisphere
is affected

25. (a) PD , (b) T1+C show multiple flow voids and contrast-enhanced tubular
structures representing a large vascular lesion that involves the entire
right cerebral hemisphere , the normal brain parenchyma is interspersed
between the abnormal vessels

26. 2-Catheter Angiography :
-The arterial feeder vessels tend to be of normal
size or only moderately enlarged, associated
stenosis of the feeder vessels are often identified
-There is extensive transdural supply to normal and
abnormal brain tissue through branches of the
ECA
-The lack of clear early venous drainage on dynamic
images is the key to differentiating this disease
from classic brain AVM

27. (a) AP RT ICA angiogram shows relatively normal-sized MCA branches and lack of early
venous drainage , findings that confirm the diagnosis of proliferative angiopathy ,
stenosis of the proximal M2 segment of the right MCA just distal to the MCA
bifurcation is also noted (arrow) , (b) Lateral RT ECA angiogram shows an extensive
transdural supply to the right cerebral hemisphere via the branches of the middle
meningeal artery

28. 7-Radiographic Features :
a) CT
b) MRI
c) Catheter Angiography

29. a) CT :
-Hyperdense enlarged serpiginous vessels
-Often speckled calcification (25 %)
-Enhance strongly

30. Left occipital arteriovenous malformation (AVM) with multiple calcified phleboliths
and numerous hyperattenuating vascular channels

31. CT+C shows a tangle of intensely enhancing tubular structures embedded in
the left parietal lobe , a finding that is compatible with a nidus ,
hyperattenuation representing intraventricular hemorrhage is noted in
the ventricles

32. b) MRI :
-Serpiginous black flow voids
-May be evidence of local atrophy and gliosis (as a
result of vascular steal and ischemia) or previous
hemorrhage
-AVM replaces but does not displace brain tissue (i.e.
mass effect is uncommon) unless complicated by
hemorrhage and edema
-Edema occurs only if there is recent hemorrhage or
venous thrombosis with infarction
-There are usually adjacent changes to the adjacent
brain including gliosis (T2 prolongation), dystrophic
calcification & blood products (blooming T2*
gradient imaging), the gliosis / encephalomalacia or
mineralization seen in the adjacent brain is due to
alteration in vascular flow from the AVM

33. T1 shows large occipital arteriovenous malformation (AVM) with parasagittal flow
void

34. T2 showing numerous flow voids

35. c) Catheter Angiography :
-Gold standard for assessment of morphology
and nidal architecture including presence of
associated arterial or venous aneurysms
(10 %), varices and stenosis
-The diagnostic criteria include :
1-Nidus embedded within the brain parenchyma
2-Early venous drainage, if the veins are seen in
the arterial phase

36. Lateral left internal carotid angiogram reveals a glomerular type nidus in a
cortical location supplied mainly by the posterior parietal and angular
branches of the left MCA with early drainage into a left parietal cortical
vein , findings that confirmed the diagnosis of a brain AVM

37. 8-Grading System : (Spetzler's Criteria)
0 1 2 3
Eloquence No Yes - -
Draining vein Superficial Deep - -
Size - >3cm 3-6cm <6cm

38. -Higher score is associated with higher chance of
hemorrhage
-Other factors associated with poorer prognosis/higher
risk of hemorrhage :
1-Intranidal aneurysm
2-Aneurysm in the circle of Willis
3-Aneurysm in arterial feeder
4-Venous stasis

39. -Eloquence of adjacent brain :
a) Eloquence brain :
-Sensorimotor, language, visual cortex,
hypothalamus, thalamus, brain stem,
cerebellar nuclei or regions directly adjacent
to these structures
b) Non-eloquence brain :
-Frontal and temporal lobe, cerebellar
hemispheres

40. 9-Complications :
a) Hemorrhage (parenchymal > SAH >
intraventricular)
b) Seizures
c) Cumulative risk of hemorrhage is
approximately 3 % per year

41. 10-Treatment Options :
a) Surgery
b) Endovascular embolization
c) Radiosurgery
d) Conservative management

42. a) Surgery :
-Patients with smaller and cortical-based brain
AVMs are likely to benefit most from surgical
resection

43. b) Endovascular embolization :
-There are no real contraindications for
endovascular therapy, however, the cure rate
with embolization alone is relatively low
( 10%-20% ) except in small lesions

44. c) Radiosurgery :
-Radiosurgery has a high cure rate with
relatively low complication rates
-However, its major limitation is that radiation is
slow to take effect, it may be up to 2 years
before any shrinkage of the brain AVM is seen

45. d) Conservative Management :
-Is typically used when the risk posed by
treatment is too high such as in large brain
AVMs or in asymptomatic patients who are
believed to have a low risk of future
hemorrhage

46. b) Dural Arteriovenous Fistula (DAVF) :
1-Incidence
2-Etiology
3-Clinical Picture
4-Location
5-Radiographic Features
6-Classification
7-Caroticocavernous fistula

47. 1-Incidence :
-Dural AVFs are abnormal connections between arteries that
would normally feed the meninges bone or muscles but not
the brain and small venules within the dura mater
-Acquired lesions presenting in older population (50-70 years)
compared to AVM (20-40 years)
2-Etiology :
-Occur following damage to venous structures (post-thrombosis,
surgery & trauma)
-They typically have multiple feeders and are usually acquired,
most frequently from as a result of neovascularisation
induced by previously thrombosed dural venous sinus
(typically transverse sinus)

48. -Therefore supply is typically from the same
branches that supply meningeal arterial supply :
a) Supratentorial : Middle meningeal artery (ECA)
b) Anterior cranial fossa : Ethmoidal branches of
the ophthalmic artery (from ICA)
c) Cavernous sinus : Dural branches from the ICA
and accessory meningeal branch of the maxillary
artery (via foramen ovale), branch of ECA
d) Posterior cranial fossa :Dural branches from the
vertebral arteries, branches from occipital and
ascending pharyngeal arteries, branches of ECA

49. 3-Clinical Picture :
-Symptoms & signs secondary to arterialization of venous
system :
a) Bruit
b) Venous hypertension
c) Pulsatile tinnitus (if primary involvement is sinuses)
d) Hemorrhage
e) Focal neurology
f) Seizures
g) Caroticocavernous fistula may give rise to proptosis &
chemosis

50. 4-Location :
a) Transverse/ sigmoid sinus : Most common
b) Cavernous sinus
c) SSS
d) Straight Sinus
e) Other venous sinuses
f) Anterior cranial fossa : Typically only ICA supply
due to meningeal supply of this region
g) Tentorium

51. 5-Radiographic Features :
a) CT & MRI
b) Catheter Angiography

52. a) CT & MRI :
-Often normal unless complications (e.g.
hemorrhage, enlargement of cavernous sinus and
superior ophthalmic veins if caroticocavernous
fistula)
-Dilated cortical veins (a condition referred to as a
pseudophlebitic) which manifest as abnormal
enhancing tubular structures or flow voids within
the cortical sulci with no true nidus within the
brain parenchyma

53. Borden type 2 dural AVF in a 45-year-old woman who presented with sudden loss of consciousness , (a) CT
without contrast shows a left temporo-occipital hematoma with intraventricular hemorrhage , (b) T2
shows multiple flow void vascular structures along the cortical sulci of both occipital regions , there is
white matter edema with T2 hyperintensity in the left occipital lobe with evidence of a resolving
hematoma , no nidus can be identified , (c) Left internal maxillary angiogram reveals a dural AVF in the left
transverse sinus supplied by branches of the left middle meningeal artery , note the associated thrombosis
of the proximal and distal parts of the transverse sinus creating an “isolated pouch” and thereby causing
reflux from the shunt into the cortical veins

54. -Hypoattenuation of the white matter at CT or
hyperintense T2 signal at MR imaging indicates
venous congestion or infarction which may
eventually lead to venous hemorrhage
-Focal enhancement of these areas may also be
observed as a sign of chronic venous ischemia
-Curvilinear subcortical calcifications can be seen at
CT in patients with long-standing cortical venous
reflux, possibly due to chronic venous congestion

55. c) Catheter Angiography :
-Still gold standard for diagnosis and
demonstration of morphology on which
classification and treatment planning based
-Demonstrate early venous filling, the
contribution from external carotid artery
branches (rather than pial vessels) and shunt
location

56. 6-Classification :
a) Cognard classification
b) Borden classification

57. a) Cognard classification :
-Correlates venous drainage patterns with increasingly
aggressive neurological clinical course
Type I : Confined to sinus wall, typically after thrombosis
Type II :
IIa : Confined to sinus with reflux (retrograde) into sinus
but not cortical veins
IIb : Drains into sinus with reflux (retrograde) into cortical
veins (10-20% hemorrhage)

58. Type III : Drains direct into cortical veins (not
into sinus), 40% hemorrhage
Type IV : Drains direct into cortical veins (not
into sinus) with venous ectasia, 65%
hemorrhage
Type V : Spinal perimedullary venous drainage,
associated with progressive myelopathy

59. b) Borden classification :
1-Type 1 :
-DAVF drainage into a dural venous sinus or
meningeal vein with normal anterograde flow
- Usually benign clinical behavior
-Equivalent to Cognard type I and II

60. 2-Type 2 :
-Anterograde drainage into dural venous sinus and
onwards but retrograde flow occurs into cortical
veins
-May present with hemorrhage
-Equivalent to Cognard type IIb and IIa+b
3-Type 3 :
-Direct retrograde flow of blood from the fistula into
cortical veins causing venous hypertension with a
risk of hemorrhage
-Equivalent to Cognard type III, IV and V

61. 7-Caroticocavernous Fistula :
a) Definition
b) Etiology
c) Clinical Picture
d) Classification
e) Radiographic Features

62. a) Definition :
-Represent abnormal communication between
the carotid circulation and the cavernous
sinus

63. b) Etiology :
-Direct CCFs are often secondary to trauma,
most commonly seen in the young male
patients, presentation is acute and symptoms
develop rapidly
-In contrast, indirect CCFs have a predilection
for the postmenopausal female patient and
the onset of symptoms is often insidious

64. c) Clinical Picture :
1-Pulsatile exophthalmos / proptosis : 75 %
2-Chemosis and subconjunctival hemorrhage
3-Progressive visual loss : 25-32 %
4-Pulsatile tinnitus (usually objective)
5-Raised intracranial pressure
6-subarachnoid hemorrhage, intracerebral
hemorrhage, otorrhagia, epistaxis : 2.5-8.5 %

65. d) Classification :
-It can be broadly classified into two main types
1-Direct : Direct communication between intra-
cavernous ICA and cavernous sinus
2-Indirect : Communication exists via branches
of the carotid circulation (ICA or ECA)

66. -Another method is to classify according to four
main types :
Type A : Direct connection between the
intracavernous ICA and CS
Type B : Dural shunt between intracavernous
branches of the ICA and CS
-Type C : Dural shunt between meningeal
branches of the ECA and CS
-Type D : B + C

67. *Direct : type A
-A direct fistula is due to a direct communication
between the intracavernous ICA and the
cavernous sinus
-There are a number of causes, however
aneurysm rupture and trauma are by far the
most common

68. *Indirect : types B, C & D
-Indirect fistulas are due to communication by
multiple branches between the ICA / ECA and CS
-The are most frequent are type C, with meningeal
branches of the ECA forming the fistula
-They are postulated to occur secondary to
cavernous sinus thrombosis with
revascularization
-Other predisposing factors appear to be
pregnancy, surgical procedures in the region &
sinusitis

69. e) Radiographic Features :
1-CT
2-MRI
3-Catheter Angiography

70. 1-CT :
-Proptosis
-Enlargement of cavernous sinus, enlarged
superior ophthalmic veins
-Extra ocular muscles may be enlarged
-Orbital edema
-May show SAH / ICH from ruptured cortical
vein

71. 2-MRI :
-Findings of CCFs include a dilated CS with multiple signal
intensity void structures that are associated with
proptosis and an enlarged superior ophthalmic vein
-On gradient-echo images, these flow voids shows high
signal intensity
-The presence of flow-related enhancement in the CS on
MRA suggests the diagnosis in the right clinical setting
-Other supporting findings are a dirty appearance of the
retro-orbital fat and enlargement of the extraocular
muscles, due to the presence of intracavernous
communications, very high-flow fistulas may result in
enlargement of both CSs

72. ICA to a CS fistula , axial source image from an MRA shows flow-
related enhancement in the medial (arrow) left CS from a direct-
type fistula

73. MRA shows an enlarged superior ophthalmic vein (arrow)

74. MRA shows a right carotid cavernous fistula (arrow)

75. 3-Catheter Angiography :
-Rapid shunting from ICA to CS
-Enlarged draining veins
-Retrograde flow from CS, most commonly into
the ophthalmic veins

76. c) Pial AVF :
1-Definition
2-Incidence
3-Location
4-Radiographic Findings

77. 1-Definition :
-Consist of a direct fistulous communication
between a pial artery and a vein without any
intervening nidus
-They differ from dural AVFs in that they derive
their arterial supply from pial or cortical
arteries and are not located within the dura
mater

78. 2-Incidence :
-Pial AVFs are more commonly encountered in
children and are frequently associated with
hereditary hemorrhagic telangiectasia
3-Location :
-Pial AVFs are located on the surface of the
brain, are often high flow lesions and in most
instances are associated with dilated venous
pouches

79. 4-Radiographic Findings :
-Clues to the diagnosis of pial AVFs at cross
sectional imaging include the presence of :
a) Dilated vessels, mainly at the brain surface
b) Asymmetric dilatation of the pial feeding artery,
either the MCA, ACA or PCA, which is best seen
at the level of the circle of Willis
-These findings can be used to differentiate pial
AVFs from dural AVFs and may be accompanied
by dilated venous pouches outside the brain
parenchyma

80. Pial AVF in a 1-week-old neonate who presented with congestive heart failure , the patient had a family history
of hereditary hemorrhagic telangiectasia , (a, b) Axial T2 reveal enlargement of the right MCA at the level
of the circle of Willis (arrow in a) and a large dilated vascular structure in the right perisylvian region
(arrowhead in b) , findings that are suggestive of a venous pouch , the upper portion of another large flow
void structure is also seen in the posterior fossa , no nidus can be identified , (c) Lateral RT ICA angiogram
reveals a high-flow fistula between an MCA branch and a large venous pouch (arrowhead) , retrograde
flow of contrast material into the basilar artery confirms the presence of another high-flow fistula
(arrows) from the posterior inferior cerebellar artery , the high-flow fistulas and venous pouches are
typical findings in a patient with hereditary hemorrhagic telangiectasia

81. Pial AVF with venous pouches and venous congestion in a 7-year-old boy who presented with
headaches , the patient had a family history of nosebleeds and mucosal telangiectasias
suggestive of hereditary hemorrhagic telangiectasia , (a,b) T2 reveal large dilated vascular
structures in the right perisylvian region suggestive of venous pouches with enlargement of
the right MCA relative to the left side (arrow in b) and no identifiable nidus , findings that are
compatible with a pial AVF , the hyperintense T2 signal of the white matter at the right
frontal lobe (arrow in a) is suggestive of venous congestion , (c) Lateral RT ICA angiogram
reveals a high-flow fistula between an MCA branch and large venous pouches

82. (ii) Malformations without AV shunts :
a) Cavernous Malformation
b) Venous Malformations
c) Capillary Telangiectasia
d) Moyamoya Disease

83. a) Cavernous Malformation :
1-Definition
2-Incidence
3-Location
4-Clinical Picture
5-Radiographic Findings

84. 1-Definition :
-Cavernous angioma (Cavernoma)
-Dilated endothelial cell-lined spaces with no
normal brain within lesion
-Usually detectable because cavernous
malformation contains blood degradation
products of different stages

85. 2-Incidence :
-All age group
-60-80 % multiple (may be familial)
-Often associated with an adjacent developmental
venous anomaly (DVA), there is increased risk of
bleeding if a DVA is present, however, the DVA itself
doesn’t have any bleeding risk
-When multiple, cavernous malformations represent an
inherited disorder called familial cavernomatosis
3-Location :
-80% supratentorial
-Occur anywhere in CNS, common in Pons

86. 4-Clinical Picture :
-Small hemorrhages (usually not associated with
large hemorrhages)
-Seizures
-Headache secondary to occult hemorrhage

87. 5-Radiographic Findings :
a) CT
b) MRI
c) Catheter Angiography

88. a) CT :
-Isodense / Hyperdense (lesion due to
calcification)
-Range in size from tiny (single focus of
susceptibility artifact) to giant

89. b) MRI :
-T2 : Popcorn lesion : bright lobulated center with
black (hemosiderin) rim
-Subacute hemorrhage and degraded blood
products within the lesion produce a halo of
signal hyperintensity around the lesion on T1-
weighted images, a useful finding for
differentiating cavernous malformations from
hemorrhagic tumors and other intracranial
hemorrhages
-Always obtain susceptibility sequences to detect
coexistent smaller lesions

90. Cavernoma in the postcentral gyrus on T1 , T2 and SWI , notice
popcorn appearance and blooming artifact

91. T2 & T2* gradient echo show multiple cavernomas , notice the popcorn appearance
with peripheral rim of hemosiderin on the T2 , the lesions are almost completely
black on the gradient echo due to blooming artefacts , T2* and susceptibility
weighted imaging (SWI) markedly increase the sensitivity of MRI to detect small
cavernomas , the five black dots in the left cerebral hemisphere on the T2* are
also cavernomas and are not visible on the T2WI

92. (a) Axial T2 shows a large left parietal mass that resembles a popcorn ball with a
hypointense hemosiderin rim (arrows) and loculated hyperintense compartments
(b) Axial T1 at the same level shows multiple high signal intensity compartments in the
lesion , findings suggestive of subacute hemorrhage , a faint halo of high signal
intensity also is visible around the lesion (arrowheads)

93. Cavernous malformation & associated DVA , T1+C show a hypointense , centrally
hyperintense nonenhancing cavernous malformation (yellow arrow) in the left
cerebellar hemisphere , directly superior to the cavernoma (b) is an enhancing
vascular structure with caput medusa morphology (red arrow) representing a DVA

94. Giant cavernous malformation (a) CT without contrast shows a hyperattenuating
complex mass (arrows) in the RT fronto-temporal lobe , (b) T1 shows the mass is
predominantly cystic & hyperintense (representing blood products) , (C) FLAIR
shows that the intracystic contents are primarily hyperintense , there is a
complete low signal hemosiderin ring surrounding the lesion (red arrows) , there is
mild surrounding edema , (d) T1+C shows no appreciable enhancement

95. c) Catheter Angiography :
-Usually normal

96. b) Venous Malformations :
1-Developmental Venous Anomaly
2-Vein of Galen Malformation
3-Venous Varix

97. 1-Developmental Venous Anomaly (Venous
Angioma) :
a) Definition
b) Radiographic Features

98. a) Definition :
-DVA is an abnormal vein that provides
functional venous drainage to normal brain
-Venous angiomas per se do not hemorrhage
but are associated with cavernous
malformation (30%) which do bleed
-DVA is a DO NOT Touch lesion, if resected, the
patient will suffer a debilitating venous infarct,
the DVA must be preserved if an adjacent
cavernous malformation is resected

99. b) Radiographic Features :
1-CT
2-MRI
3-Catheter Angiography

100. 1-CT :
-Only enhanced scans may show linear vein
draining to ependymal lining of ventricle or
cortex with inverse umbrella-shaped (caput
medusa) leash of vessels draining towards
anomalous veins

101. 2-MRI :
-Medusa head or large transcortical vein best
seen on spin-echo images or after
administration of gadolinium
-Location in deep cerebellar white matter or
deep cerebral white matter
-Adjacent to the frontal horn (most common
site)

102. T1+C

103. DVA & a tiny cavernous malformation , (a) T1+C shows a subtle curvilinear
enhancing structure (yellow arrow) in the RT frontal white matter
representing a DVA , (b) Susceptibility weighted shows a focus of
susceptibility artifact (red arrow) , suggestive of an adjacent cavernous
malformation

104. 3-Catheter Angiography :
-Medusa head seen on venous phase (hallmark)
-Dilated medullary veins draining into a large
transcortical vein

107. 2-Vein of Galen Malformation :
a) Definition
b) Types
c) Radiographic Findings

108. a) Definition :
-Complex group of vascular anomalies that
consist of a central AVM and resultant varix of
the vein of Galen (incorrectly referred to as
vein of Galen aneurysm)

110. b) Types :
-Two main types exist with the common feature
of a dilated midline venous structure :
1-Vein of Galen AVM
2-Vein of Galen varix

111. 1-Vein of Galen AVM :
-Primary malformation in development of vein of Galen
-AV shunts involving embryologic venous precursors
(median vein of prosencephalon)
-Choroidal arteriovenous fistula with no nidus
-Absence of normal vein of Galen
-Median vein of prosencephalon does not drain normal
brain tissue
-Manifests as high-output congestive heart failure
(CHF) in infants and hydrocephalus in older children

113. Median prosencephalic vein of Markowski shown in an artist’s impression , its
afferent arteries are the choroidal arteries and the anterior cerebral
artery (ACA)

114. 2-Vein of Galen Varix :
-Primary parenchymal AVM drains into vein of
Galen which secondarily enlarges
-Thalamic AVM with nidus is usually the primary
AVM
-Uncommon to present in neonates
-Higher risk of hemorrhage than the vein of
Galen AVM

115. c) Radiographic Findings :
1-Ultrasound
2-Catheter Angiography
3-CT & MRI
4-Chest Radiography

116. 1-Ultrasound :
-First choice imaging modality
-Sonolucent midline structure superior / posterior
to 3rd ventricle
-Color Doppler ultrasound (US ) to exclude
arachnoid/developmental cyst
2-Catheter Angiography :
-Used to determine type and therapy
-Endovascular embolization : therapy of choice

120. Lateral view of the RT ICA angiogram, the arterial supply including the left
anterior pericallosal artery (arrows), right medial posterior choroidal
arteries (small arrowhead), and right lateral posterior choroidal arteries
(large arrowhead) are shown

121. Lateral view of the LT ICA angiogram, multiple feeding arteries from the left
medial posterior choroidal arteries (small arrowhead) and left lateral
posterior choroidal arteries (large arrowhead) demonstrate shunting at
the inferior-caudal portion of the dilated galenic vein (arrow)

123. (a) Sagittal T1 shows the markedly enlarged median prosencephalic vein of
Markowski, characteristic of VGAM (arrow), arterial feeders can be seen along the
anterior wall of the vein, (b) the complex arterial maze (arrows) is well seen on this
conventional angiogram obtained with injection of the left vertebral artery, coils
can be seen along the right side of the varix, occluding several arterial feeders

124. 3-CT & MRI :
-Indicated to assess extent of brain damage that
influences therapy
4-Chest Radiography :
-High-output CHF, large heart

125. CT angiography axial image showing enlarged median prosencephalic vein
( large arrow) with multiple arterial feeders ( small arrows)

126. CT angiography sagittal image showing enlarged median prosencephalic vein
(black arrow) continuing in the falcine sinus (red arrow) with enlarged
confluence of sinuses

127. (a & b) Sagittal reconstructions of CT angiograms showing choroidal type ,
vein of Galen malformation in a neonate , the falcine draining sinuses are
massively enlarged because of narrowing of both sigmoid sinuses

128. CT+C

129. In utero diagnosis of vein of Galen malformation , MRI performed in the third
trimester showing a dilated midline vascular structure in sagittal (a) , axial
(b) and coronal (c) planes

130. T1 T2

131. T1 T2

132. T2, the dilated galenic vein, namely the median vein of prosencephalon (thick
arrow), located midline in the cistern of velum interpositum, drains into
the parietal superior sagittal sinus (thin arrow) via the persistent primitive
falcine sinus (arrowhead)

133. Chest X-Ray AP view showing cardiomegaly with prominent
vascular markings

135. c) Capillary Telangiectasia :
1-Definition
2-Location
3-Radiographic Features

136. 1-Definition :
-Nests of dilated capillaries with normal brain
interspersed between dilated capillaries
-Commonly coexist with cavernous malformation
-A Do NOT Touch lesion
2-Location :
-pons > cerebral cortex, spinal cord > other
locations

137. 3-Radiographic Features :
a) CT
b) MRI
c) Catheter Angiography

138. a) CT :
-Is often normal
b) MRI :
-Foci of increased signal intensity on contrast-enhanced
studies
-T2 : hypointense foci if hemorrhage has occurred
c) Catheter Angiography :
-Is often normal but may show faint vascular stain

139. (a) T1+C Patient with midbrain capillary telangiectasia showing brush-like
enhancement in the right midbrain , (b) Gradient shows subtle increased
susceptibility in the right midbrain

140. GRE T1 T1+C

141. d) Moyamoya Disease :
1-Definition
2-Clinical Picture
3-Radiographic Findings

142. 1-Definition :
-Uncommon occlusive disease of unknown origin
that classically involves the supraclinoid internal
carotid arteries with relative sparing of the
posterior fossa in the early stages
-The term moyamoya syndrome is used in cases in
which no underlying cause (atherosclerosis,
Down syndrome, neurofibromatosis, sickle cell
disease or some other condition) can be
identified

143. -There is usually development of extensive tiny
basal perforator collateral vessels ( the
moyamoya vessels ) which have been
described as having a puff of smoke
appearance at cerebral angiography and of
transdural collateral vessels

146. 2-Clinical Picture :
-Differs between pediatric and adult
populations:
a) Most children present with transient ischemic
attack or cerebral infarctions
b) Approximately one-half of adults present with
intracranial hemorrhage from rupture of the
moyamoya collateral vessels

147. 3-Radiographic Findings :
a) CT & MRI
b) Catheter Angiography

148. a) CT & MRI :
-Imaging include the presence of tiny flow voids,
commonly seen arising from the basal cisterns
and extending into the basal ganglia or the
thalamus
-There is no true nidus embedded within the
brain parenchyma and no dilated vessels
-The diagnosis can be suggested by the presence
of bilateral supraclinoid internal carotid artery
stenosis at MRA and CTA

150. b) Catheter Angiography :
-Cerebral angiography remains necessary for
preoperative evaluation for the
revascularization of moyamoya disease
-There is usually development of extensive tiny
basal perforator collateral vessels the
moyamoya vessels) which have been
described as having a puff of smoke
appearance

151. -The multitude of secondary collateral pathways
(basal moyamoya perforator collateral
vessels, transdural supply from the middle
meningeal arteries to the convexity and
through the ophthalmic artery to the ACA
branches) can often be evaluated only with
digital subtraction angiography due to their
small size

152. MRA

153. Typical features of moyamoya disease, including severe stenosis
of the bilateral ICA (arrows) and basal collateral networks

154. Sequencing of the right carotid anteroposterior angiograms from initial (A) to
early (B), mid (C), and late (D) arterial filling, it shows steno-occlusion of
the anterior and middle cerebral arteries, fine vascular networks (arrows)
from the lenticulostriate arteries anastomose with medullary arteries,
which eventually reconstitute the middle cerebral artery