Table 3.
Stenosis range N method | ICA PSV | ICA/CCA PSV ratio | ICA EDV | Plaque |
---|---|---|---|---|
Normal | < 125 cm/s | < 2.0 | < 40 cm/s | None |
< 50% | < 125 cm/s | < 2.0 | < 40 cm/s | < 50% diameter reduction |
50–69% | 125–230 cm/s | 2.0–4.0 | 40–100 cm/s | > 50% diameter reduction |
70-near occlusion | > 230 cm/s | > 4.0 | > 100 cm/s | > 50% diameter reduction |
Near occlusion | May be low or undetectable | Variable | Variable | Significant, detectable lumen |
Occlusion | Undetectable | Not applicable | Not applicable | Significant, no detectable lumen |
EDV = end diastolic velocity; ICA/CCA = internal carotid artery/common carotid artery; PSV = peak systolic velocity