NASCET Calculator — Carotid Stenosis % tool (NASCET Method)

NASCET Carotid Stenosis Calculator

Calculate percent carotid stenosis using the NASCET method: percent stenosis = (1 − (narrowest diameter / distal normal ICA diameter)) × 100. Enter measurements in millimetres (mm) or centimetres (cm).

1. Narrowest luminal diameter at stenosis

Enter the smallest residual lumen diameter measured at the stenosis (linear diameter).

2. Diameter of the normal distal cervical ICA (reference)

Measure an unaffected segment of the distal ICA just beyond the bulb to use as the reference diameter.

Optional: Patient symptomatic status

Symptomatic Asymptomatic Unknown

This is for contextual classification only (calculator does not give treatment advice).