Vascular Imaging Flashcards Preview

735: Orthotics and Prosthetics > Vascular Imaging > Flashcards

Flashcards in Vascular Imaging Deck (19)
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1
Q

What is an ankle brachial index (ABI)?

A

a non-invasive measure of peripheral tissue perfusion used to rule out arterial disease

2
Q

How is an ABI performed?

A

In supine: Obtain brachial and ankle (highest of either the anterior tibialis or posterior tibialis arteries) systolic blood pressures

Then calculate the ratio of the BP of the LE compared with UE

3
Q

What is considered a significant difference between systolic BPs on an ABI?

A

more than 10 mmHg difference in R to L sides

4
Q

ABI = ____SBP/_____SBP

A

ankle

brachial

5
Q

ABI Interpretation:

__-__ = Vessel Calcification
__-__ = Normal
__-__ = Mild arterial insufficiency
__-__ = Moderate arterial insufficency, intermittent claudication
Less than __ = Severe arterial insufficiency and resting pain
Less than __ = Ischemic or gangrenous extremity and resting pain

A
  1. 1 -1.3
  2. 1 - 0.90
  3. 9-0.70
  4. 70-0.50
  5. 5
  6. 3
6
Q

Describe why the ABI may be misleading in patients with diabetes mellitus. What SBP should be used instead of the ankle BP in these patients?

A

Because they can have artificially elevated ankle pressures which underestimates the severity of the disease

Toe pressures

7
Q

What is the gold Standard for vascular evaluation?

A

Continuous Wave Doppler

8
Q

How is a continuous wave Doppler performed?

A

Cuffs are placed at the levels of the proximal & distal thigh, calf & ankle

9
Q

What is considered a significant finding on a continuous wave Doppler?

A

20 mmHg or greater reduction between segments of leg or between same levels of opposite leg

10
Q

What are the advantages of duplex scans?

A
  • Provides accurate localization & quantification of lesions
  • Differentiates stenosis from occlusions
  • Provides precise answers about specific arterial segments
  • Measures flow velocities in bypass grafts
  • Can follow known lesions for evidence of progression
  • Can monitor vascular reconstructions for development of stenosis
11
Q

What are the disadvantages of duplex scans?

A
  • time consuming

- expertise needed

12
Q

What does transcutaneous O2 mapping do?

A

provides a measure of tissue hypoxia by looking at O2 tension of skin (mmHg) and can then provide a predictor of wound healing success or failure

13
Q

What does a laser Doppler measure?

A

skin perfusion during and after bypass procedures

14
Q

What is the advantage of performing a Magnetic Resonance Angiography (MRA)?

A

Measures LE ischemia in patients with a contraindication to standard contrast Angiography

15
Q

What is Computed Tomography Angiography used to detect?

A

clots in veins or narrowing/obstructions in arteries

16
Q

When is contrast angiography indicated?

A

In patients without contraindications to contrast medium who are about to undergo revascularization

17
Q

What can be defined as the time it takes for toe surface color to return to normal after removal of pressure?

A

capillary refill test

18
Q

What is normal capillary refill?

A

3 seconds or less

19
Q

What special test can help detect venous insufficiency but is not very sensitive or specific?

A

Homan’s sign