Qué hace esta calculadora
Converts measured residual lumen and reference diameters into NASCET and ECST percentage estimates.
Enter the narrowest lumen, distal normal ICA, and estimated original bulb diameter.
Antes del cálculo
- Confirm the narrowest residual lumen and use the reference diameter required by the selected method.
- Assess near-occlusion and occlusion morphologically before relying on a percentage calculation.
Alcance clínico
Use the calculator for extracranial internal carotid artery stenosis when the narrowest residual lumen and the method-specific reference diameter can be measured reliably on CTA or MRA.
Aplicabilidad y exclusiones
- Near-occlusion and complete occlusion must be recognized morphologically; a simple percentage can be misleading.
- NASCET and ECST use different reference diameters, so their percentages are not interchangeable.
Método y lógica de cálculo
NASCET compares the narrowest lumen with the normal distal ICA. ECST compares it with the estimated original diameter at the stenosis. Always state the method with the percentage.
NASCET stenosis = (1 - narrowest lumen / distal normal ICA) × 100ECST stenosis = (1 - narrowest lumen / estimated original bulb) × 100Tabla de interpretación
| NASCET result | Common descriptor |
|---|---|
| <50% | Mild |
| 50-69% | Moderate |
| 70-99% | Severe; exclude near-occlusion |
| No patent lumen | Occlusion; assess directly, not by formula |
Errores frecuentes
- Mixing the NASCET distal normal ICA denominator with the ECST estimated original bulb denominator.
- Reporting a percentage without naming the method or calculating near-occlusion as routine stenosis.
The formulas quantify diameter reduction; they do not adjudicate near-occlusion, occlusion, or treatment eligibility.
Ejemplo práctico
Caso: Fictional example: narrowest lumen 1.5 mm, distal normal ICA 5.0 mm, estimated original bulb 6.0 mm.
Cálculo: NASCET = 70%; ECST = 75%.
Interpretación: Report both only when both reference measurements are defensible, label each method, and separately assess near-occlusion.
Cómo usar esta calculadora
- Completa los campos visibles de imagen y medición. Los datos obligatorios están indicados en la herramienta.
- Revisa la categoría, la puntuación, las mediciones y cualquier recomendación o advertencia calculada.
- Copia el texto para el informe solo después de comprobar el resultado con la exploración completa y la guía de referencia.
Preguntas sobre esta calculadora
Why are NASCET and ECST percentages different?
They use different reference diameters: distal normal ICA versus estimated original bulb diameter.
Can near-occlusion be calculated reliably as a percentage?
Often no. Distal collapse changes the reference diameter, so morphological criteria and guideline-specific reporting are required.
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