Venous Doppler, also known as venous ultrasound, uses sound waves to create images of your blood vessels and the blood within them. Vein doctors use venous Doppler to determine the cause of varicose veins and to search for blood clots, narrowing of blood vessels, tumors and other abnormalities within the veins. Venous surgeons also use venous Doppler to plan treatment of the affected veins.
Venous ultrasound looks at blood flow in the large arteries and veins in the arms and legs. It works by emitting sound waves and using the sound waves that bounce back to create an image. Venous Doppler is a special type of imaging technology, in that it captures images in real-time, showing structure and movement of blood vessels and blood flow.
Ultrasounds utilized the same principles involved with sonar, used by bats, ships and fishermen. When a sound wave hits something, the sound wave bounces and echoes back. Ultrasound measures these echo waves to determine how far away the object is, and provides information about the object’s size and shape. Measuring the echo waves can also establish the object’s consistency to determine if it is solid or filled with liquid. Vein doctors use traditional ultrasound to create images of arteries and veins.
A Doppler is different from standard ultrasounds, however, in that it can take pictures of the blood flowing inside the veins. It does this through the Doppler effect, which is the change in frequency of sound waves as the blood and the transducer move closer or away from each other.
What to Expect during Venous Doppler
There are usually no special preparations for having a venous Doppler. Be sure to tell your vein doctor about your medical history and supply a list of all your medications. Wear comfortable clothing that allows you to expose the testing area; you may need to wear a gown in some cases.
You will sit comfortably on an examination table as the ultrasound technician or clinician applies paste over the veins to be examined. The health care professional will apply a gel to a hand-held transducer that directs high-frequency sound waves to your veins. They may apply blood pressure cuffs to your arms or legs. Sometimes the practitioner will press on a vein to be sure it does not have a clot. You may feel pressure.
The transducer captures the returning sound waves, and sends information about those waves to a computer that converts data into images displayed on a monitor. The computer creates the images based on the loudness, pitch, and time it takes for the ultrasound signal to return from the blood vessel to the transducer. The computer program takes into account the type of body structure being imaged and the composition of tissue through which the sound travels.
Because it uses sound waves rather than ionizing radiation, venous Doppler is safer than x-rays. There are no known harmful effects from this type of imaging. Venous Doppler is quick and painless.