|
Several types of imaging tests are used to obtain information
about the condition of the vascular system. These tests
are non-invasive and usually pain-free. Tests offered
include:
Carotid ultrasound
Doppler ultrasound
Duplex ultrasound imaging
Magnetic resonance angiography (MRA)
Pulse volume recording using plethysmogram
Segmental pressure measurement
Carotid Ultrasound
Ultrasound imaging uses reflected sound waves to produce
pictures of the inside of the body. The images are captured
in real-time and can show the structure and movement
of the body's internal organs, as well as blood flowing
through blood vessels. A carotid ultrasound is an ultrasound
of the body's two carotid arteries, which are located
on each side of the neck and carry blood from the heart
to the brain, provide detailed pictures of these blood
vessels.
In an ultrasound examination, a hand-held instrument
(transducer) both sends the sound waves and records
the echoing waves. When the transducer is pressed against
the skin, it directs a stream of inaudible, high-frequency
sound waves into the body. As the sound waves bounce
off of internal organs, fluids and tissues, the sensitive
microphone in the transducer records tiny changes in
the sound's pitch and direction. These signature waves
are instantly measured and displayed by a computer,
which in turn creates a real-time picture on the monitor.
These live images are usually recorded on videotape,
and one or more frames of the moving pictures typically
are captured as still images.
Doppler Ultrasound
A Doppler ultrasound examines blood flow through the
major arteries and veins in the arms, legs and neck
by using reflected sound waves. The ultrasound will
indicate blocked or reduced blood flow through narrowing
in the major arteries of the neck and is instrumental
in the prevention of strokes and other diseases of the
heart and vascular system. The Doppler ultrasound also
can be used to reveal blood clots in the leg that may
block blood flow to the lungs.
As in a carotid ultrasound, the procedure involves
a transducer that is passed lightly over the skin. For
doppler ultrasound, the transducer is passed above a
blood vessel. The sound waves bounce off solid objects,
including blood cells, which causes a change in pitch
of the reflected sound waves. If there is no blood flow,
the pitch does not change.
Duplex Ultrasound Imaging
Duplex ultrasound imaging is used to take high-resolution images of the carotid arteries in order to determine the potential for narrowing or blockage of these blood vessels, limiting blood flow to the brain. The ultrasound radiologist uses a combination of Doppler analysis and real-time ultrasound imaging to view images on a monitor during the examination. Photographs also can be taken and examined later for further study. The images are created by converting echoes of soundwaves from the ultrasound machine into electronic signals. For this reason, the patient may hear some unusual noises during the exam. Duplex ultrasound imaging is pain-free and non-invasive and usually can be completed in less than 30 minutes.
Magnetic Resonance Angiography (MRA)
Magnetic resonance angiography is a common diagnostic procedure that uses harmless magnetic fields and pulses of radio waves to produce two-dimensional or three-dimensional images of the blood vessels. This process is used to examine the arteries for potential bulges or aneurysms, tears, narrowing, hardening, inflammation or blockages. The patient lies on a table that slides into a donut-shaped machine that processes the magnetic fields and radio waves into images. Unlike a computed tomography (CT) scan, an MRA doesn’t involve exposure to X-rays. The MRA procedure typically lasts between 30 to 90 minutes.
Pulse Volume Recording Using Plethysmogram
Pulse volume recording, also known as plethysmography, is a painless, non-invasive test that measures blood flow within the arteries in order to help locate blockages. Pulse volume recording usually is performed on the arms and legs to help diagnose conditions of the peripheral vascular system. It also may be used to diagnose thoracic outlet syndrome or spasms of the finger arteries, a condition known as Raynaud's disease.
It is done by placing 3 or 4 blood pressure cuffs on the area to be examined, for example, the patient's thighs, calves or ankles. These cuffs are connected to a pulse volume recorder, and each pulse appears as a waveform on a chart. The shape of these waveforms helps the physician diagnose possible blockages. These measurements are compared to each other, or in some cases, will be taken before and after exercise and compared. The pulse volume recording typically lasts 30 minutes.
Segmental Pressure Measurement
Segmental pressure measurement is a simple test that
is used to diagnose vascular diseases in the arteries
of the arms and fingers. Like the pulse volume recording
test, segmental pressure measurement involves applying
pressure to certain points along the arms and fingers
to measure blood flow. The information then is analyzed
to determine a need for further treatment.
If you would like to make an appointment or need assistance
to find an appropriate physician, please call us at
(888) LUHS-888.
Related Links
Vascular treatments
|
