Vascular Mod 2

Question 1

Circle of Willis components

Answer 1

1) anterior communicating artery
2) anterior cerebral arteries
3) supraclinoid segment of ICA (terminal ICA)
4) posterior communicating arteries
5) posterior cerebral arteries

Question 2

Collateral pathways to the ophthalmic artery

Answer 2

1) supratrochlear with superficial temporal

2) dorsal nasal with facial

Question 3

MCA segments

Answer 3

M1, M2, M3

Question 4

Anatomic variants of COW

Answer 4

1) intact 50%
2) PCA from ICA 25%
3) absent ACA (A1 segment) 25%
4) absent posterior communicating 20%
5) hypoplastic PCA (P1 segment) 15%
6) absent anterior communicating 0.3%

Question 5

TCD insonation window and corresponding arteries

Answer 5

Temporal

1) MCA
2) ACA
3) PCA
4) Terminal ICA

Orbital

1) OA
2) ICA siphon

Occipital

1) vertebral
2) basilar

Question 6

MCA TCD settings

Answer 6

1) Flow towards probe
2) Depth 30-60 mm
3) Velocity 41-76 cm/s

Question 7

MCA/ACA bifurcation TCD findings

Answer 7

1) bidirectional flow

2) depth 46-86 mm

Question 8

ACA TCD settings

Answer 8

1) flow away from probe
2) Depth 60-70 mm
3) Velocity 41-76 cm/s

Question 9

Terminal ICA TCD settings

Answer 9

1) Flow towards probe
2) depth 55-66 mm
3) Velocity 46-66 cm/s
4) inferior angle

Question 10

PCA (p1 segment) TCD settings

Answer 10

1) Flow towards probe
2) depth 60-70 mm
3) Velocity 33-64 cm/s
4) posterior/inferior angle

Question 11

Basilar TCD settings

Answer 11

1) Flow away from probe
2) Depth 80-120 mm
3) Velocity 30-57 cm/s

Question 12

Vertebral TCD settings

Answer 12

1) Flow away from probe
2) Depth 60-70 mm
3) Velocity 27-55 cm/s

Question 13

Ophthalmic artery TCD settings

Answer 13

1) Flow towards probe
2) Depth 40-50 mm
3) Velocity 18-26 cm/s
4) Normal high resistance

Question 14

Carotid siphon TCD settings

Answer 14

Supraclinoid = away from probe
Genu = bidirectional
Parasellar = towards probe

Depth 60-80 mm

Question 15

Normal and vasospasm velocity in MCA

Answer 15

< 120 cm/s = normal
120-200 cm/s = moderate angiographic spasm
> 200 cm/s = severe vasospasm

Question 16

Difference between vasospasm and atherosclerotic stenosis

Answer 16

1) vasospasm not as focal
2) vasospasm involve multiple vessels
3) vasospasm velocity are dynamic with time

Question 17

TCD settings

Answer 17

1) PW
2) large sample volume (5-13 mm)
3) 2MHz or lower