Have velocity measurements or velocity ratios been validated for carotid artery disease stenosis greater than 50%?

• A. Yes
• B. No
• C. Only in select research studies
• D. Not studied at all

Answer: (B)

Velocity-based criteria in carotid duplex are most well-validated for higher-grade stenosis, but there isn’t a universally accepted validation for measurements or velocity ratios when stenosis is greater than 50%. In practice, robust, standardized thresholds are established for more severe disease, yet the accuracy and reliability of using velocity alone—or even ICA/CCA velocity ratios—to quantify stenosis above 50% are not consistently validated across broad patient populations. This means that when the stenosis could be over 50%, velocity data alone are not considered fully validated for precise grading, and additional imaging confirmation (such as CTA or MRA) is typically used to make a definitive assessment.