1. What is Carotid Stenosis?

Carotid stenosis refers to the narrowing of the carotid arteries, typically caused by atherosclerosis. It's a major risk factor for stroke. The degree of stenosis is a key factor in determining treatment options.

2. How Does the Calculator Work?

The calculator uses the NASCET method formula:

Where:

• Min Diameter — Narrowest diameter of the stenosis (mm)
• Normal Diameter — Diameter of the normal artery beyond the bulb (mm)

Explanation: This formula calculates the percentage reduction in arterial diameter compared to the normal vessel diameter.

3. Importance of Stenosis Measurement

Details: Accurate stenosis measurement is crucial for clinical decision making. Treatment thresholds are typically at 50% and 70% stenosis for symptomatic patients.

4. Using the Calculator

Tips: Enter both diameters in millimeters. The minimum diameter must be less than or equal to the normal diameter. Measurements are typically obtained from ultrasound, CTA, or MRA.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between NASCET and ECST methods?
A: NASCET uses the normal distal carotid diameter as reference, while ECST uses the estimated original diameter at stenosis site.

Q2: What percentage is considered significant stenosis?
A: Generally ≥50% for symptomatic patients, ≥60-70% for asymptomatic patients may warrant intervention.

Q3: How is this measured clinically?
A: Typically via Doppler ultrasound, CT angiography (CTA), or MR angiography (MRA).

Q4: Are there limitations to diameter measurement?
A: Yes, eccentric plaques may require additional views. Other methods include area stenosis measurement.

Q5: What other factors affect treatment decisions?
A: Symptom status, plaque characteristics, surgical risk, and patient comorbidities all influence management.