Doppler Ultrasound Exam:
Venous
What is a
Venous Doppler Ultrasound Exam?
A venous Doppler ultrasound is a diagnostic test used to check the
circulation in the large veins in the legs (or sometimes the arms).
This exam shows any blockage in the veins by a blood clot or “thrombus”
formation.
Normal Circulation
The veins return blood to the heart. There are two sets of veins
in the legs:
- Deep veins – which are underneath the leg muscles.
- Superficial veins – which are right underneath the surface
of the skin.
The veins in the leg deflate
easily; blood flows under low pressure and against gravity. Two
things help the blood pump more efficiently:
- The calf “muscle pump.” As you walk, calf muscle
movement pushes blood upward.
- Venous valves – the one-way valves in the veins that
prevent blood from flowing back into your feet.
Thrombophlebitis
Superficial thrombophlebitis is a clot that has formed in the veins
near the surface of your skin. Clotting can occur after injury or
in old varicose veins. Superficial thrombophlebitis usually responds
very well to local treatment.
Venous thrombosis (sometimes
called phlebitis) is a blood clot in a deep vein, resulting in partial
or complete blockage of blood flow in that vein. The symptoms of
this deep vein thrombosis (sometimes called DVT) can be vague. Pain,
swelling and redness are usually found.
Unlike superficial thrombophlebitis, a DVT is a serious health concern,
because it’s possible that the clot could break off and travel
to your lungs. It is then referred to as a pulmonary embolus. The
risk of pulmonary embolus is decreased if you recognize the symptoms
of a DVT quickly and get it treated right away.
Risk Factors
No one understands completely why some people are more likely than
others to develop a DVT. Some situations increase the chance of
clots forming in the deep veins:
- Surgery or injury
- Long-term bedrest or immobility
- Pregnancy
- Obesity
- A history of venous thrombosis
Diagnosis
If your doctor thinks you might have a venous disorder, he or she
may order a diagnostic exam to determine what type of a problem
you have and how bad it might be.
Getting Ready
for the Exam
You will come to the Vascular Lab for a venous Doppler/ultrasound
duplex exam. This test involves no needles, catheters or dye. Ultrasound
is used to listen to the flow of the blood through your veins. Please
allow 30 to 45 minutes for the exam. Often, the examination can
be completed in less time.
What Will I Feel
During the Exam?
Don’t worry – because there are no needles or anything
else inserted into your body, the test is completely painless and
has no side effects. You will be lying on a stretcher, and your
clothing will be removed from the waist down. The technician will
ask you several questions about why your physician ordered the exam.
The recordings are received by running a small, smooth probe over
various parts of your legs or arms. This will show if there is blockage
in the large veins.
The doctor who ordered the test for you will receive the results
within two to three days and tell you the results. If the technician
thinks that there is a possibility of a DVT, he or she will notify
your physician while you are still in the office.
Washington University physicians are the medical staff of Barnes-Jewish Hospital and St. Louis Children's Hospital
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