Tests for Veins - Duplex Ultrasound Report
O - Means that the vein is open, the flow of blood is normal and there is no backward flow (no reflux of blood) - Therefore the VALVES ARE WORKING.
X - Means that the vein is open but the blood is being allowed to flow the wrong way through the vein (reflux of blood) - Therefore the VALVES ARE NOT WORKING.
