Veins, the blood vessels that carry blood back to the heart, work against the force of gravity. The calf muscles and a system of one-way valves in the veins help maintain the flow of blood toward the heart. A variety of tests can assist in the diagnosis of venous disease:
- Pulse volume recording (PVR), with segmental blood pressure impedence – measures venous blood flow and capacity using cuffs that are placed around the leg to monitor blood as it pulses through the blood vessels by recording changes in the volume of air within the cuff
- Photoplethysmography (PPG) – uses infrared light to assess blood flow near the surface of the skin. Light waves create a picture of what is taking place in the veins.
- Venous duplex study – an imaging (ultrasound) test of your major leg or arm veins to determine whether blockage or thrombus (clot) is present. Slight compressions are done on the areas being imaged, and the blood flow is sampled at designated locations.
- Vein mapping – the process of locating, marking and measuring veins in the arms or legs before bypass surgery or hemodialysis access