RadEssentialReading-room reference
Carotid stenosis: SRU Doppler & NASCET
SRU consensus Doppler criteria for ICA stenosis (NASCET-equivalent percentages). ICA PSV and plaque estimate are the primary parameters.
| Stenosis | ICA PSV | Plaque estimate | ICA/CCA PSV ratio | ICA EDV |
|---|---|---|---|---|
| Normal | <125 cm/s | None | <2.0 | <40 cm/s |
| <50% | <125 cm/s | <50% | <2.0 | <40 cm/s |
| 50–69% | 125–230 cm/s | ≥50% | 2.0–4.0 | 40–100 cm/s |
| ≥70% (not near occlusion) | >230 cm/s | ≥50% | >4.0 | >100 cm/s |
| Near occlusion | High, low, or undetectable | Visible | Variable | Variable |
| Total occlusion | Undetectable | Visible, no lumen | N/A | N/A |
NASCET on CTA/DSA
% stenosis = (1 − narrowest ICA lumen ÷ normal distal cervical ICA diameter) × 100
Calculate
NASCET–
In near occlusion, the distal ICA is collapsed and NASCET underestimates severity; report as near occlusion rather than a percentage.
Sources
- Grant EG, Benson CB, Moneta GL, et al. Carotid artery stenosis: gray-scale and Doppler US diagnosis — Society of Radiologists in Ultrasound Consensus Conference. Radiology. 2003;229:340–346.PubMed ↗
- North American Symptomatic Carotid Endarterectomy Trial Collaborators. Beneficial effect of carotid endarterectomy in symptomatic patients with high-grade carotid stenosis. N Engl J Med. 1991;325:445–453.PubMed ↗
Radessential summarizes published classification systems for practicing radiologists. Summaries are condensed; confirm details against the cited source before relying on them for patient care.