Grading | Percentage of arterial stenosis in lower limb | Doppler ultrasound finding | Number of patients N = 36 |
Normal | - | Normal triphasic flow | 9 |
Grade 1 | 1% to 19% stenosis | Normal triphasic flow | 12 |
Grade 2 | 20% to 49% stenosis | Triphasic waveform with an increase in peak systolic velocity ≥30% with respect to the proximal recording site | 9 |
Grade 3 | 50% to 99% stenosis: | Monophasic waveform with an increase in peak systolic velocity ≥100% and marked spectral broadening. Distal waveform is abnormal | 4 |
Grade 4 | 100% stenosis: |
| 2 |