Table 1:

Velocity grading criteria based on the NASCET angiographic method13,14

StenosisICA PSV (cm/s)ICA EDV (cm/s)CCA/ICA PSV Ratio
0–29<100<40<3.2
30–49110–130<40<3.2
50–59>130<40<3.2
60–69>13040–1103.2 to <4.0
70–79>210120–140≤4.0
80–95>210>140≤4.0
96–99String flowString flowString flow
100OccludedOccludedOccluded

  • Note:—CCA indicates common carotid artery; EDV, end diastolic velocity.