Unit 8: Normal Doppler

Question 1

What is the ICA/CCA ratio?

Answer 1

Highest PSV ICA divided by PSA mid CCA

Question 2

You shopuld avoid using the doppler on a curve, but if you must…what should you do?

Answer 2

Set center of angle cursor parallel to walls.

Question 3

How should you place the doppler around a calcific shadow?

Answer 3

Steer SV under calcified plaque from each end.

Question 4

What should you listen to post shadow?

Answer 4

High velocities and post-stenotic turbulence.

Make a comparison of each end of the shadow; look for big changes proximal to distal.

Question 5

What are the characteristics of an ICA doppler?

Answer 5

• Low resistance
• Diastolic flow above zero unless in bulb.
• End diastolix velocity higher than ECA

Question 6

What are the characteristic of an ECA doppler?

Answer 6

• High resistance
• Diastolic flow near or below zero
• End diastolic velocity lower than ICA

Question 7

What are the characteristic of an CCA doppler?

Answer 7

• Combination of ICA and ECA
• End diastolic velocity between ICA and ECA

Question 8

What are the differences between an ECA and ICA waveform?

Answer 8

ECA waveform: Often shows a notch in the downslope/

ICA waveform: Constant forward flow above baseline.

Question 9

How do you preform a temporal tap?

Answer 9

1. Find STA pulse in front of ear.
2. Tap STA in front of ear and check for taps in waveform.
3. Check opposite vessel and compare affect of tapping on each.

Question 10

Why is the temporal tap useful even though it is not 100% accurate?

Answer 10

It is helpful if you don’t see any ECA branches in color or ECA has a similar wave shape to ICA.

Question 11

How is the CCA psv proximally?

Answer 11

May be higher

Question 12

what are the differences in the ICA psv?

Answer 12

• Low in bulb then higher in mid ICA
• Highest in bulb near ECA, reverses in bulb area farthest from ECA

Question 13

How is the ECA psv?

Answer 13

Typically higher than ICA

Question 14

What are the characterisitcs of a vertebral waveform?

Answer 14

A normal vertebral waveform is like the ICA, low resistance.

Question 15

How is the SCA velocities compared to the carotid arteries?

Answer 15

Normall triphasic with higher psv than carotid arteries.