| Primary Parameters | Additional Parameters | |||
|---|---|---|---|---|
| Degree of Stenosis (%): | ICA PSV (cm/sec) | Plaque Estimate (%)* | ICA/CCA PSV Ratio | ICA EDV (cm/sec) |
| Normal | <125 | None | <2.0 | <40 |
| <50 | <125 | <50 | <2.0 | <40 |
| 50–69 | 125-230 | ≥50 | 2.0-4.0 | 40-100 |
| ≥70 but less than near occlusion | >230 | ≥50 | >4.0 | >100 |
| Near occlusion | High, low, or undetectable | Visible | Variable | Variable |
| Total occlusion | Undetectable | Visible, no detectable lumen | Not applicable | Not applicable |
* Plaque estimate (diameter reduction) with gray-scale and color Doppler US.
Grant EG, Benson CB, Moneta GL, Alexandrov AV, Baker JD, Bluth EL, et al: Carotid artery stenosis grayscale and Doppler ultrasound diagnosis-Society of Radiologists (SRU) in Ultrasound Consensus criteria