Week 5 - Lesson 2 (Part 1) Flashcards
Stenosis
The narrowing of the arterial lumen, causing a hemodynamically significant change in flow
What can a significant stenosis cause?
Collateralization
- if its progressive
Total occlusion
The complete blocking of flow within an arterial lumen
When does collateralization occur?
If occlusion is not a sudden occurrence as with an emboli lodging in a small lumen
Where does plaque commonly form?
At the common carotid bifurcation
- involves distal CCA, Prox ECA/bulb, Prox ICA
How can plaque be characterized? (5)
- Homogenous
- Soft
- Heterogenous
- Ulcerated
- Calcified
What needs to be evaluated with plaque? (6)
- Extent
- Location
- Surface contour
- Texture
- Assess degree of luminal stenosis
- Evaluate in both transverse and sagittal projections
What is the best way to evaluate and characterize plaque?
Gray scale US
What is considered abnormal intima thickness?
> 0.9mm
Homogenous plaque
Generally uniform echo pattern and smooth surface
- 80-85% of patients
What does calcified plaque produce?
Posterior acoustic shadowing
How does calcified plaque appear on US?
Very echogenic
Does calcified plaque occur in symptomatic or asymptomatic patients?
Asymptomatic
Heterogenous plaque (2)
- Complex echo pattern
- contains one or more sonolucent areas - Cauliflower calcification appearance
Ulcerated plaque (4)
- Focal depression or break in plaque surface
- Irregular border contour
- Emboli twinkle artifact
- Hard plaque in the proximal ICA