Carotid ultrasound is a non-surgical and painless test that is used to determine the amount of blockage of your carotid arteries. This is done by using ultrasound to create an image of the inside of the arteries.
This narrowing of the arteries is called “stenosis,” and is considered to be a big risk factor for strokes. There are two such arteries, one on either side of the neck. These arteries carry blood to the brain, and if this blood flow is interrupted, it can result in a stroke.
An ultrasound imaging of your carotid arteries is one of a number of tests that can be done to determine the extent of blockage or stenosis. There are several types of ultrasounds used. If you need this screening procedure, you should discuss with your doctor which version is appropriate for you.
Types of Carotid Ultrasound
There are two main types of tests that are used to image the carotid arteries.
- Doppler ultrasound: This test actually creates images of the blow flow though the arteries.
- Standard ultrasound: This test creates an image of the actual structure of the inside of the arteries.
Why are these tests performed?
The doctor may order a carotid ultrasound because he or she suspects there may be blockages or other types of damage to the artery wall that can prevent blood from getting to the brain, causing what is called an ischemic stroke, which is life threatening.
The problem may be a blood clot, or something called an artery dissection which is a damaging split in the artery wall. This condition can impede blood flow, or seriously weaken the artery wall, possibly leading to a stroke.
Another problem can be a narrowing of the artery because of plaque buildup involving bad cholesterol levels, which is called stenosis. This can be indicated by something called a bruit, which is a sound the doctor hears when using a stethoscope to externally examine your carotid arteries.
These abnormal sounds can indicate stenosis, so the doctor uses the carotid ultrasound to further determine just what is happening inside the arteries. There are other things that might cause the doctor to suspect artery disease such as:
- High blood pressure
- Advanced age
- Bad cholesterol levels
- Birth defects that affect the carotid arteries
- TIA’s (transient ischemic attacks)
- Tumors (very rare)
Who would perform the test?
This test is performed by a medical professional called a radiological technician. This is a person trained in both the procedure and preparation for medical imaging scans. The test will sometimes be performed by a doctor called a radiologist. These physicians are experts on performing and analyzing the results of medical imaging scans.
The radiologist will analyze the carotid ultrasound results and give your doctor a diagnosis based on the imaging scans of your carotid arteries.
How carotid ultrasound works
The equipment operated by the radiological technician generates high frequency sound waves that are projected into your body by a hand-held instrument called a transducer. When these sound waves strike your tissue and are reflected back to the transducer, it creates an image of the shape and structure of the tissues being scanned.
The biggest advantage of carotid ultrasound is that it is non-invasive, meaning that no piercing or cutting of the skin surface is necessary, and that the scanning technology uses sound waves which are much safer than other imaging technologies that use ionizing radiation which can damage tissue.
How is this test performed?
This test is usually performed in a hospital or sometimes in an outpatient clinic. It takes about an hour and usually involves the following steps:
1) You dress in a standard patient exam gown sometimes called a Johnny. You can also wear your own clothing as long as the neck area is open and there is no jewelery around your neck.
2) You lie on the exam table, on your back, and the radiological technician applies a gel to your neck that helps the equipment make proper contact with your skin.
3) The tech will then place something called an ultrasound transducer on your skin. This is a hand held instrument that sends the sound waves into your body. As the tech moves it around on your neck it produces an image of your carotid artery and surrounding area. This process is completely painless.
4) When the ultrasound is finished the gel gets wiped off. You will have to wait a few minutes until the tech or radiologist makes sure that the scan is complete, and then they will send you home.
5) Your doctor will then contact you with the results of your scan and the diagnosis he has been given by the radiologist.
The carotid ultrasound is a very valuable test because it allows your doctor to see exactly how much plaque buildup there is in your carotid arteries and then create a treatment protocol based on this precise information. This test could warn you in time to prevent a stroke or other serious medical problem, which makes it one of the most effective tests for prevention there is.