Unit 12: Abnormal Carotid B-mode measurements

Question 1

Why do we care about % stenosis?

Answer 1

Stenosis %= higher risk.

Question 2

Where can you find the tightest stenosis?

Answer 2

• Tighest stenosis is highest % stenosis
• Tighest stenosis has the smallest lumen.
• Tightest stenosis typically has highest velocity

Question 3

What are the two ways to estimate stenosis on ultrasound?

Answer 3

1. Doppler velocity criteria
2. B-mode.

Question 4

What are some other iaging modalities also used to measure stenosis?

Answer 4

• Angiography
• CTA
• MRA

Question 5

How should you scan to find the smallest lumen to measure a stenosis?

Answer 5

Move proximally and distally in transverse.

Question 6

If calcification is obscurring the tighest point what should you do?

Answer 6

DOCUMENT.

Question 7

How should you get the full effect of plaque and an accurate measurement?

Answer 7

Take images in multiple planes.

• Trans
• Long AP
• Long LAT
• Oblique

Question 8

How do you measure the Duplex % Stenosis?

Answer 8

1-A/B X 100

Question 9

How do you measure a Angio (NASCET) % Stenosis?

Answer 9

1-A/C X 100

Question 10

What does the Arteriogram measurement measure?

Answer 10

It measures the tighest residual lumen at stenosis in ICA and compare to the distal normal ICA where walls are parallel.

Question 11

What does the Duplex image measurement measure?

Answer 11

It measures the smallest residual lumen at the stenosis and compares it to the true lumen at the stenosis because we can see the wall beyond the plaque.

Question 12

What does the NASCET measure?

Answer 12

It measures the smallest residual lumen at the stenosis and compares it to the lumen at a point distal to the stenosis where the walls are parallel

Question 13

How do you measure a stenosis?

Answer 13

• Carefully identify the true lumen.
• Use color
• Measure transverse diameters through center of vessel
• Measure long view perpendicular to flow.

Question 14

How should you measure a stenosis in order to report the average?

Answer 14

Measure in long and transverse.

Question 15

Where should you measure in transverse?

Answer 15

Find the tighest lumen to measure.

Question 16

Why do you want to be careful with color when measuring?

Answer 16

To avoid bleeding over plaque or underestimating the true lumen.

Question 17

When should you not measure?

Answer 17

On a poor image.

Question 18

T/F:

A plaque shelf cannot be measured accurately.

Answer 18

True.

Question 19

What is the first tool used to grade a stenosis?

Answer 19

Doppler velocity.

• PSV
• ICA/CCA ratio
• EDV

Question 20

When should an explanation be sought upon results?

Answer 20

If velocity and image disagree.

Question 21

What does IMT mean?

Answer 21

Intima media thickness.

Question 22

What is the IMT?

Answer 22

It is the double line normally seen in CCA when artery is horizontal on screen.

Question 23

What is the first echogenic line ?

Answer 23

It is the lumina-intima interface.

Question 24

What is the second echogenic line called?

Answer 24

It is the media-adventia interface.

Question 25

What is the thickness of the echo (IMT) used for?

Answer 25

It is used to predict atherosclerosis or classify patients with cardiovascular disease.

Question 26

Where is the IMT measured?

Answer 26

DIstal CCA is used for this measurement.

Question 27

T/F:

CIMT decreases linearly with age.

Answer 27

False.

It increases linearly with age.

Question 28

How do you find the mean CIMT?

Answer 28

(.009 x Age)+.116

Question 29

CIMT’s >75th percentile suggest what?

Answer 29

Increased risk of cardiovascular disease.

Question 30

An increased IMT’s is commonly associated with what?

Answer 30

• MI
• Stroke
• Death from heart disease.

Question 31

What is plaque defined as?

Answer 31

>1.5 mm