Ultrasound is an essential diagnostic tool because of its safety, convenience and effectiveness. It produces images of the body's internal structures through the use of high-frequency sound waves, the echoes of which are used to create moving and still images. All images appear in "real" time as soon as the machine is turned on, and the transducer (a handheld device that sends and receives sound waves) placed on the body; there is no wait, as there is for X-rays and other imaging procedures, for images to be developed.
Carotid ultrasound is used to examine the two carotid arteries, which are located on either side of the neck. The carotid arteries divide into internal and external; the internal ones supply blood to the brain, and the external ones supply blood to the face, neck and scalp.
Candidates for Carotid Ultrasound
Carotid ultrasound is typically performed to look for artery-clogging plaque, which can lead to strokes or other serious complications. A candidate for carotid ultrasound has recently had a stroke or mini-stroke; has a carotid bruit, which is an abnormal sound in the artery that is heard under stethoscopic examination; is suspected of having a blood clot in an artery; is suspected of having a split in the wall of the artery; has recently had carotid endarterectomy to clear a blockage; or has recently had a stent inserted. Carotid ultrasound is also used as a preventive screening test for anyone at high risk for having a stroke.
When Should You Have Your Carotid Arteries Checked?
Studies indicate the carotid artery disease typically occurs after coronary artery disease. Therefore, adults diagnosed with that precursor may want to schedule a carotid artery ultrasound. The risk factors for carotid artery disease are similar to those associated with other cardiovascular conditions, so individuals with those risk factors may be interested in ultrasound imaging as a preventive measure. We commonly perform this test on patients who have been diagnosed with carotid artery disease to monitor the effectiveness of medical or surgical intervention. If you have questions about this screening or its appropriateness for your health needs, please feel free to contact us. We are happy to discuss your situation and provide you with the information you need to make an educated decision about your health care.
How Do I Prepare for a Carotid Ultrasound?
There is little to do to prepare for your carotid ultrasound. Because the screening is performed on the neck area, you should wear a comfortable, loose shirt that does not close around the neck. Turtlenecks should be avoided. Also, wear a shirt that can be washed easily in case it picks up some of the ultrasound gel. Because you will lie down for your test, we recommend wearing comfortable clothing in which you can move easily on and off the table.
You may be advised to avoid smoking and caffeine for some time before your carotid ultrasound. Chemicals like caffeine and nicotine can shrink the blood vessels, which could impair the accuracy of your test results. Dr. Ken Stevens encourages patients not to smoke or drink caffeine for two or more hours before their test, along with being well hydrated.
Are There Any Risks/side Effects From a Caortid Ultrasound?
Ultrasound technology does not use ionized radiation, as is common in x-rays. This imaging test works by sending inaudible sound waves through the skin and tissue of the body. The sound waves bounce off of structures. In the case of the carotid artery ultrasound, the sound waves bounce off of the arterial walls, circulating blood, and plaque that may have formed in the artery. Ultrasound imaging is extremely safe and has no known side effects.
How Long Does a Carotid Ultrasound Take?
This ultrasound examination is usually completed within about 30 minutes. Patients may be advised to allow for up to an hour for their entire appointment. Carotid ultrasounds are relatively quick and easy to tolerate. Unless the ultrasound is performed on an area that is tender, the screening should be painless. After positioning the patient on the exam table, the sonographer applies the ultrasound gel and then moves the transducer back and forth, delivering sound waves to view the artery in question. During the ultrasound, you may be asked to rotate or tilt your head so the sonographer can capture the most accurate views from various angles. When your test is complete, you can immediately resume your normal activities.
The Carotid Ultrasound Procedure
The ultrasound procedure begins with the patient's lying down on an examination table. A water-based gel is applied to both sides of the neck. The gel allows consistent contact between the body and the transducer by eliminating any air pockets that could get in the way. The transducer is held firmly against the skin, and slowly moved back and forth; the images then appear on the computer screen.
How Accurate is Carotid Artery Ultrasound?
Doctors have relied on ultrasound imaging for many years. This screening, which does not require radiation exposure, provides an immediate view of the body at work. Ultrasound waves “bounce” off of organs and vascular structures as they move. In the veins and carotid arteries, this enables Dr Stevens to see how blood is moving through the vessels and to spot any obstacles that are preventing optimal circulation. In the instance of carotid artery ultrasound, the screening is very accurate in its depiction of the vein in real-time, even identifying the presence of arterial plaque.
What is a Normal Carotid Ultrasound Result?
A normal carotid ultrasound result means that no evidence of stenosis (narrowing) was seen on the image. The absence of stenosis indicates that circulation is moving as it should through the carotid artery to the brain and parts of the face. When narrowing is seen in the artery, the result is typically reported in percentage terms. The percentage result defines the degree of stenosis that showed on the image. Dr. Stevens then determines the best course of medical care based on the percentage result of the carotid artery ultrasound analyzed alongside other risk factors for stroke or other cardiovascular events.