L19: Interventional Neuroradiology

Question 1

What are some of the endovascular and percutaneous treatments offered by interventional neuroradiology?

Answer 1

• treatment of strokes – embolectomy (remove clot)
• stenting the carotid/neck artery
• repairing aneurysms of the head and neck (dilated arteries)
• blocking vascular malformations
• treating painful vertebral body fractures – vertebroplasty

Question 2

What is carotid atherosclerosis?

Answer 2

build-up of fatty deposits forming plaque along the inner layer of the arteries, which narrows the arteries and decreases/blocks blood flow to the brain

Question 3

What are the options for treatment of carotid atherosclerosis?

Answer 3

• medical optimization
• carotid endarterectomy (open surgery)
• carotid angioplasty or stenting

Question 4

In what situations might carotid stenting be preferred over endarterectomy?

Answer 4

• previous neck surgery or radiation
• very deep (retropharyngeal) carotid or large body habitus
• high perioperative risk for general anesthetic
• less than age 70

Question 5

What is an intracranial aneurysm?

Answer 5

expanding of arteries due to weakened area in the wall of the vessel in the brain

Question 6

What are the two methods for endovascular intracranial aneurysm repair?

Answer 6

• aneurysm coiling
• flow diversion

Question 7

What is aneurysm coiling?

Answer 7

insertion of small metal coils into the aneurysm to stop blood flowing into the aneurysm and reduce the risk of a bleed or re-bleed

Question 8

What is flow diversion?

Answer 8

use of catheter to place a stent (soft, flexible mesh tube) into the blood vessel where there is an aneurysm

Question 9

What is a vertebroplasty?

Answer 9

treating fractures with cement to stabilize the fragments and improve recurrent pain

Question 10

What is CT perfusion?

Answer 10

scan that uses contrast to assess blood flow/perfusion to affected territory (ie. head)

Question 11

What can CT perfusion help determine?

Answer 11

can discriminate core infarct (small localized area of dead tissue resulting from failure of blood supply) from ischemic penumbra (reversibly injured brain tissue around the ischemic core)

• total ischemic territory: time to peak enhancement (Tmax) > 6 seconds
• core infarct: cerebral blood flow (CBF) < 30%

Question 12

CT Perfusion

What is the mismatch ratio?

Answer 12

relative proportion of potentially salvageable brain

• (volume of Tmax > 6 s) / (volume of CBF < 30%)

Question 13

CT Perfusion

What is the hypoperfusion index?

Answer 13

predictor of collateral flow

• (volume of Tmax > 10 s) / (volume of Tmax < 6 s)
• good collaterals if HIR < 0.4