How It Is Done continued...
Testing may be done before and after
exercise, if you are healthy enough.
Veins in the arms and legs
For this test, you will
be asked to lie down and breathe normally. You must lie very still. Any changes
in blood flow that occur as a response to your breathing patterns are
The test may be repeated while the examiner presses on the
veins close to the surface of your skin to help detect a clot in the vein
(called a compression maneuver). The examiner may do this with your legs or
arms in different positions to ensure that the blood supply is not blocked in
these positions. The examiner may also squeeze your calf or forearm to help
blood move more quickly through the veins (called an augmentation maneuver).
This is done to evaluate blood flow toward your heart.
legs are being tested, you may also be asked to try to breathe out strongly
with your nose pinched and your mouth closed (called a
Valsalva maneuver). This maneuver usually causes a
sudden change in blood flow through the veins.
Arteries in the neck
You will be asked to lie down
with a pillow underneath your head for support. The test is performed on both
sides of your neck, and then the results are compared to standard values to
determine the amount of blockage or narrowing of the arteries.
For a transcranial
ultrasound, the transducer is passed lightly over the skin at the base or side
of your skull.
The transducer is moved back and
forth on your belly until the doctor finds the blood vessel that needs to be
studied. After the doctor has found the blood vessel, it may take some time to
check the blood flow.
How It Feels
There is normally no discomfort involved
with having a Doppler ultrasound test. The gel may feel cold when it is put on
your skin unless it is first warmed to body temperature. If your blood pressure
is taken during the test, you will feel pressure when the blood pressure cuff