Vascular malformations

Question 1

Syndromes associated with multiple AVMs

Answer 1

HHT (hereditary hemorrhagic telangiectasia)

CAMA (cerebrofacial arteriovenous metameric syndrome)

Question 2

Grading system for AVMs

Answer 2

Spetzler-Martin (higher grade, more risk of bleeding: over 2-4% risk of bleeding per year for AVMs)

Size (small <3, med 3-6, large>6 cm)
Location (non-eloquent, eloquent)
Venous drainage (superficial, deep)

Question 3

Factors associated with increased risk of bleeding in AVMs

Answer 3

Location (periventricular, basal ganglia, thalami, post fossa)
Feeding artery or nidus aneurysm
Central venous outflow obstruction/stenosis
Deep venous drainage

Question 4

Grading system for dural AVFs

Answer 4

Cognard Classification System - primary prognostic features is presence/degree of cortical venous drainage

Type I - No cortical venous drainage
Type IIA - Reflux into dural sinus, not cortical veins
Type IIB - Reflux into cortical veins (10-20% bleeding)
Type III - Direct cortical drainage - HIGH RISK OF BLEED
Type IV - Direct cortical drainage + venous ectasia - HIGH RISK OF BLEED
Type V - Spinal venous drainage

Question 5

Most common location for dural AVF

Answer 5

Transverse sinus (at/near skull base)

Question 6

Imaging findings in dural AVF

Answer 6

• multiple arterial feeders
• tortuous, engorged pial veins (“pseudophelbitic pattern”)
• thrombosed sinuses
• flow reversal in sinuses and cortical veins - MAJOR RISK FOR HEMORRHAGE DUE TO HIGH PRESSURES

Question 7

Difference between direct versus indirect CCF

Answer 7

Direct - hole in the cavernous segment of the ICA with direct connection to cavernous sinus
Indirect - dural AVF in the wall of the cavernous sinus (dural ICA or ECA branches shunt to cavernous sinus)

Question 8

Most common imaging finding of CCF

Answer 8

• reflux into superior ophthalmic vein (dilated), exoophthalmous
• extra vessels in the cavernous sinus region

Question 9

Clinical and imaging features of Vein of Galen Malformation

Answer 9

Occurs in neonates/infants
HIGH OUTPUT CARDIAC FAILURE
AVF from the choroidal arteries to median prosencephalic vein (MPV)
Subtypes: Choroidal (many feeding vessels) versus mural (few feeding vessels)
Falcine sinus in 50%

Question 10

Risk of bleeding of cavernoma

Answer 10

0.25-0.7% per year (much less than dAVF and AVM which are 2-4% per year); up to 5% if previous bleed

Question 11

Imaging appearance of capillary telangiectasia

Answer 11

Faint, paint-brush like area of high T2/low T2* signal with minimal enhancement (incidental!!)

Question 12

Sinus pericranii imaging findings

Answer 12

Communication between the extra-cranial venous system (i.e. scalp varies) and dural venous sinuses through single or multiple bony defects; need to be treated due to risk of hemorrhage

Question 13

Which vascular lesions can be occult by vascular imaging

Answer 13

Cavernoma

Question 14

Imaging appearance of cavernoma

Answer 14

Lobulated high T1/T2 signal, popcorn like, peripheral rim of hemosiderin; look for ass. DVA

Question 15

DO NOT TOUCH VASCULAR LESIONS

Answer 15

1) DVA

2) Capillary telangiectasia