What are they for?
Several types of imaging tests are used to obtain information about the condition of the vascular system. These can diagnose a range of conditions, including carotid artery disease, peripheral artery disease and abdominal aortic anyeurisms.
How are they done?
A doppler ultrasound examines blood flow through the major arteries and veins in the arms, legs and neck by using reflected sound waves. The test is a noninvasive way to determine where you might have blocked or reduced blood flow. A hand-held instrument (transducer) emits sound waves and records the echoing waves. When the transducer is pressed against your skin, it sends a stream of high-frequency sound waves into the body. As the sound waves bounce off internal organs, fluids and tissues, the microphone in the transducer records tiny changes in the sound's pitch. A computer then translates the sound waves into a real-time picture on a monitor.
A carotid ultrasound specifically looks at the body's two carotid arteries, which are located along the neck and carry blood from the heart to the brain.
Duplex ultrasound imaging takes high-resolution pictures of the carotid arteries to determine the potential for narrowing or blocking of the blood vessels, which could limit blood flow to the brain. During the exam, an ultrasound radiologist uses a combination of Doppler analysis and real-time ultrasound imaging to project images on a monitor.
Magnetic resonance angiography
Magnetic resonance angiography (MRA) uses harmless magnetic fields and pulses of radio waves to produce two-dimensional or three-dimensional images of the blood vessels. The screening is used to check the arteries for potential bulges or aneurysms, tears, narrowing, hardening, inflammation or blockages. Unlike a computed tomography (CT) scan, an MRA doesn’t involve exposure to X-rays.
Pulse volume recording
Pulse volume recording, also known as plethysmography, is a painless, noninvasive test that measures blood flow within the arteries to help locate blockages. Pulse volume recording usually is performed on the arms and legs. It is done by placing three or four blood pressure cuffs on the area to be examined. 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 with each other, or in some cases, measurements taken before and after exercise will be compared.
Segmental pressure measurement
The 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 specific points along the arms and fingers to measure blood flow. The information then is analyzed to determine a need for further treatment.
The Loyola difference
Loyola is a nationally recognized leader in cardiac care. U.S. News & World Report ranked us as a top 20 hospital for cardiology and heart surgery in 2011, making this our ninth year in the top 50.