How to do TCD chapter alex

Question 1

Where is ICA bifurcation

Answer 1

at 65mm (60-70)

Question 2

How far can you follow A1

Answer 2

start 65 follow to 75-80

Question 3

How do you find P1/P2

Answer 3

You go to ACA/MCA at 63
Angle posteriorly 10-30 degrees
Flow gap between ICA and pCA signals
P1 toward probe, P2 away between 55 - 75
Store pCA signals w/ highest velocity

Question 4

Depth for transorbital insonation?

Answer 4

50-52. Distal oA signal at 52
Inc 60-65 to find carotid siphon
Store signal at 63 - carotid siphon genu (C3)X

Question 5

How to insonate from transforaminal approach

Answer 5

1 cm south of midline, set depth to 75 point at bridge of nose to find distal vertebral and basilar.

Question 6

What depth for b mode imaging

Answer 6

16 cm so you cam get across whole skull, then reduce depth to 8-10 to measure ipsilateral anterior circulation

Question 7

Which side is the posterior circulation on compared with anterior with TCDI

Answer 7

Posterior on the right, anterior on the left

Question 8

Effect of diffuse or elongated stenosis on velocity?

Answer 8

Not necessarily increased, may even be decreased or normal