Hi dgoochb,
Carotid Duplex Scans
http://www.healthyhearts.com/carotidduplex.htm
"The two carotid arteries are the main blood vessels that supply blood
to the brain. They originate from the main arteries of the body (the
aorta and brachiocephalic artery) in the chest and travel up through
the neck and into the skull. Atherosclerosis of the right or left
carotid artery is the most common cause of a stroke.
A carotid duplex scan is a technique to take a picture of these
arteries using sound waves (ultrasound). A soundwave transducer is
placed gently on the neck. The walls and interior of the artery are
visualized and the velocity of blood flow through the artery is
measured. From this data, the presence and severity of narrowing due
to atheroscleosis can be determined.
No patient preparation is required. No needles or injections are
involved. The test generally takes about 30 minutes to perform."
=================================================
Understanding Your Test or Procedure
http://www.library.umc.edu/pe-db/pe-spec-tests.html
MRI scan
Stands for "magnetic resonance imaging." MRI scan uses large magnets
to take pictures of the brain. MRI is not as good as CT for seeing
blood right away, but is better than CT for seeing ischemic
(low-blood-flow) strokes and for seeing strokes in the lower part of
the brain called the brainstem. There is no pain involved in having an
MRI scan, but the patient must fit in a long tube, and the MRI machine
often makes a loud, pounding noise. Patients who are afraid of closed
spaces may require sedation before having an MRI. Those who are too
heavy or whose shoulders are too broad cannot undergo MRI. It is best
for the patient to close his or her eyes during an MRI scan in order
not to suffer from the "closed in" feeling.
MRA
Stands for "magnetic resonance arteriography" (or "angiography"). To
the patient, MRA is the same as MRI. The only difference is that the
technician changes the dials and buttons on the MRI machine so that
pictures are taken of the brain arteries rather than the brain itself.
Carotid duplex
Also called carotid "ultrasound" or "Doppler." In this painless test,
a technician rubs jelly and a probe over the patient's neck, using
sound waves to take pictures of the two carotid arteries. The carotid
arteries are the pulses in the neck. They are the two main arteries
that supply blood to the front and top of the brain.
=================================================
Examining the Carotid Artery.
http://www.umm.edu/patiented/articles/how_strokes_transient_ischemic_attacks_diagnosed_000045_5.htm
"The physician usually first examines the carotid artery to determine
if it is severely narrowed. If it is, the patient is in danger of a
major stroke. (The thickness of carotid artery is also proving to be a
valuable indicator for long-term risks for stroke, as well as heart
disease and mortality rates in general.)
The physician may use a number of approaches to determine the
thickness of the artery:
An important clue to a blocked carotid artery is a bruit. This is a
whooshing sound caused by blood flow turbulence in the narrowed
artery. A physician may be able to hear a bruit using a stethoscope.
Occasionally, even a patient can hear the sound. The presence of a
bruit, however, is not necessarily a sign of an impending stroke, nor
does the absence of a bruit indicate an unblocked artery.
Carotid ultrasound is a very valuable tool for measuring the width of
the artery. At this time, ultrasound is most useful in people between
the ages of 40 and 60 years. It should be noted that severely blocked
carotid arteries may distort some measurements, so other tests may be
required to confirm the results."
(See Diagram/Image)
"Carotid duplex is an ultrasound procedure performed to assess blood
flow through the carotid artery to the brain. High-frequency sound
waves are directed from a hand-held transducer probe to the area.
These waves "echo" off the arterial structures and produce a
2-dimensional image on a monitor, which will make obstructions or
narrowing of the arteries visible.
Measuring blood pressure to the eye may also be important in
identifying problems in the carotid artery. If blood flow to the eye
is reduced, then it is likely that the carotid artery is severely
narrowed.
Other Imaging Techniques. Other imaging techniques may be useful for
identifying small clots or other indicators of risk in the brain.
Transcranial duplex sonography is an ultrasound technique that can
identify tiny clots in the brain that do not produce symptoms but
place patients at higher risk for TIAs or stroke. In one study, the
use of this technique to identify blockage in large arteries in the
brain was very helpful in predicting the outlook for patients who had
experienced an ischemic stroke. It may eventually prove to be useful
in identifying unruptured aneurysms.
Magnetic resonance imaging (MRI) scan is an accurate way of evaluating
the blood vessels and the brain's circulation. This technique can even
identify silent brain injuries in elderly patients with neurologic
impairment but no symptoms of stroke, but it is very expensive and not
routinely used."
=================================================
Diagnostic Testing
http://www.cedars-sinai.edu/2431.html
Duplex Scans
"Duplex scans are a sensitive form of ultrasound done of the neck when
narrowing of the carotid arteries due to plaque buildup is suspected.
It is often the first test used when you are being evaluated for
surgery to reopen a blocked artery (carotid endarterectomy). In
carotid artery ultrasound scanning, high-pitched sound waves are
bounced off the blood vessels and tissues of the neck to create an
image of the arteries. Duplex scanning, which is a newer technique
than traditional carotid artery ultrasound and now used more often, is
able to measure blood flow at many points in the blood vessel at one
time. It is used more often than older carotid ultrasound methods.
During duplex scanning, an instrument is moved over both sides of the
neck. The resulting two-dimensional picture shows clearly the amount
of blockage in the artery. This method also shows color pictures that
indicate how fast blood is flowing in any point in the blood vessel.
Although carotid ultrasonography is quicker, safer, less painful and
less expensive than carotid arteriography, it may not always be as
accurate in determining the amount of blockage of blood flow as some
other tests. However, carotid ultrasonography is often the first test
used and can be used to decide if further tests are needed. Using
similar technology, transcranial Doppler imaging is an ultrasound of
the head."
Keyword search:
carotid artery tests
carotid artery
carotid duplex scan MRI/MRA
carotid artery scan
carotid artery scan procedures
Best regards,
tlspiegel |
