2. Vascular malformations involving the brain are divided
into
• arteriovenous malformations (AVM)
• developmental venous anomalies (DVA)
• cavernous malformations
• capillary telangiectasia.
3.
4.
5.
6.
7.
8. Angiography
• Selective : evaluation of AVM and entire cerebral
circulation
• Super selective : Microcatheters advanced into distal
aspect of arterial feeders to study anatomical
structure
9. Angiography
• Demonstrating the nidus
• Multiple arterial feeders
• Thrombosed dural sinus
• Flow reversal in sinus and cortical vein
10.
11.
12. • Arterial territories supplying the AVM
• Feeding pedicles
• High flow arteriopathy(stenose,ectasia,aneyrysm)
• Venous drainage(territories,deep,superficial)
• Individual draining veins
• High flow venous angiopathy (dural sinuses,venous
stenoses,occlusions )
• Venous drainage of normal brain parenchyma
Goals selective angiography
13. Nidus
• Fistulous-Large calibre direct
AV connection
• Plexifom-conglomerulate of
multipe small vascular
channels supplied by one or
more arterial feeders and
draining veins
14. Dural arteriovenous fistula
• Dural arteriovenous fistulas (AVF) are pathologic
abnormal vascular connections between dural
arteries with the venous sinuses or cortical veins
27. CT
• NECT: usually normal
• CECT: Normal /small tortous dural feeders
Enlarged dural sinuses
Enlarged superior opthalmic vein in CCF
Enlarged cortical draining veins
Curvilinear subcortical calcifications
28.
29.
30. Curvilinear subcortical calcifications can be seen at CT
in patients with long-standing cortical venous reflux,
possibly due to chronic venous congestion
31. MRI
• TIWI and T2WI- Flow voids and thrombosed sinus
• T2 & Flair-Hyperintensities due to venous
congestion/ischemia
• T1C+ diffuse dural enhancement
• MRV- Occluded sinus and collateral flow
• 3D PC MRA with low velocity encoding- identify
feeding arteries,fistula and flow reversal in draining
veins
39. -dAVF second most common site
-Abnormal communication between carotid artery &
cavernous sinus
-Shunt between the meningeal branches of internal or
external carotid and dural veins near the cavernous
sinus
Carotid Cavernous Fistula (CCF)
40.
41. CT & MRI
CT:
• – Marked dilation & enhancement of cavernous sinus
• – May see prominent SOV
MRI:
• – Abnormal flow voids in cavernous sinus
• – Enlargement of cavernous sinus
42.
43.
44. AVM
• Brain arteriovenous malformations (AVMs) are
abnormal vascular connections within the brain that
are congenital
Diagnostic criteria:
• Presence of nidus
• early venous drainage
45. High and Low flow malformations
High flow
• arteriovenous malformation (AVM)
• parenchymal AVM
• dural arteriovenous fistula (DAVF)
• mixed AVM
Low flow
• capillary telangiectasia
• cavernous haemangioma
• venous malformations
• developmental venous anomaly (DVA) (venous angiomas)
• vein of Galen malformation (can be high flow as well)
49. MRI
• Variable
• Punctate appearance on T2 due to single void
• Large arteries and veins are characteristic
• Intracerebral hematoma with high signal on T1
• Surrounding halo –hyposignal on T2 indicating
hemosidrren
• Post contrast not facilitate detactability like CECT
50.
51.
52. VEIN OF GALEN MALFORMATION
• Arteriovenous fistula involving a neurysmal dilatation
of median prosencephalic vein (MPV)
• Most common extracardiac cause of high-output
congestive heart failure in newborns
• < 1% of cerebral vascular malformations
53.
54.
55.
56.
57. Venous angiomas
• aberrant venous drainage of one or both cerebral
hemispheres.
• They are shown on MRI as a slightly curvilinear
structure traversing cerebral substance, representing
a single draining vein into which numerous cerebral
veins converge.
• They are often incidental findings, but may be
associated with (parenchyma) haemorrhage or focal
brain damage
58.
59.
60.
61. Telangiectasia
• Shown on MRI as small lesion
• Hypointense on T1
• T1 C+ (GAD) : may demonstrate ill defined focal
enhancement
• Hyperintense on T2
62.
63. cavernous hemangioma
• Slow flow lesions
• Accounts for 10-15%
• No intervening brain
• No mass effect on imaging
• CT usually normal if small
lesion or in absence of
calciication and hemorrgage
• Characteristic feature is
hypointense rim because of
hemosiderin
Spetzler-Martin grade 1 temporal brain AVM in a 15-year-old boy who presented
with sudden onset of headaches followed by seizures.
Axial CT scan reveals
A small hyperattenuating lesion in the right temporal lobe, compatible with a small intraparenchymal
hematoma.(b) Lateral right internal carotid angiogram Demonstrates a small(<3-cm) brain AVM supplied mainly by the temporal branches of the right MCA, with superficial drainage into the right vein of Labbe.
