Carotid Ultrasound
(Carotid Doppler)
View other tests
What is the
test?
Ultrasound uses sound waves instead of radiation
to generate snapshots or moving pictures of structures
inside the body. This imaging technique works
in a manner similar to radar and sonar, developed
in World War II to detect airplanes, missiles,
and submarines that were otherwise invisible.
After coating your skin with a lubricant to reduce
friction, a radiologist or ultrasound technician
places an ultrasound transducer, which looks
like a microphone, on your skin and may rub it
back and forth to get the right view. The transducer
sends sound waves into your body and picks up
the echoes of the sound waves as they bounce
off internal organs and tissue. A computer transforms
these echoes into an image that is displayed
on a monitor.
Doppler ultrasound is a variation of this technique
that not only shows internal structures but also
examines the flow of blood through blood vessels.
Using the Doppler effect—the change in
the frequency of sound or light waves as they
bounce off a moving object—this kind of
ultrasound produces an image of blood in motion.
A Carotid ultrasound shows the amount of blood
flow in the carotid arteries, the major blood
vessels to the brain located on either side of
your neck. With this imaging technique, your
doctor can see if there is any narrowing of your
carotid arteries because of cholesterol deposits
or some other problem. This test is often used
to evaluate people who have had a stroke or who
might be at high risk for one because of reduced
blood flow in the carotid arteries.
Back to top >
How
do I prepare for the test?
No preparation is necessary.
Back to top >
What
happens when the test is performed?
After squirting some clear jelly onto one side
of your neck to help the ultrasound sensor slide
around easily, a technician places the sensor
against your skin. An image then appears on a
video screen (see Figure 14). As the technician
moves the sensor back and forth on your neck,
different views of the carotid artery appear
on the screen. As the equipment measures the
blood flow through the artery, you hear a noise
that sounds like your heartbeat. The other side
of your neck is checked in the same way. This
test usually takes 15–30 minutes.
Back to top >
What
risks are there from the test?
There are no risks.
Back to top >
Must
I do anything special after the test is over?
No.
Back to top >
How
long is it before the result of the test is
known?
The technician records the test on videotape
for review by a radiologist. The radiologist
then makes measurements from the video picture
and submits a report to your doctor. Your doctor
should have the results within a few days.
Back to top >
View
other test |
HOME
MY
CART
