Vascular Mod 5

Question 1

Velocity ratio calculation

Answer 1

Velocity in stenosis / velocity before stenosis

Normal < 2

Question 2

Spectral waveform at different level of stenosis

Answer 2

Normal = triphasic no broadening
1-19% = triphasic, minimal SB, PSV increase < 30%
20-49% = Triphasic, prominent SB, PSV increase 30-100%
50-99% = Monophasic, extensive SB, PSV > 100%, distal waveform monophasic/dampened
Occluded = no flow

Question 3

Post-intervention follow up scans

Answer 3

q3 months for 1 year
< 50% stenosis: q6-12 months
50-75% stenosis: q3-6 months

Question 4

In stent stenosis criteria

Answer 4

> 50%
VR > 2-2.5
PSV > 180

> 70%
VR > 3.5
PSV > 300