A carotid ultrasound is a test that uses ultrasound (high-frequency sound waves) to create images of the carotid arteries – the main arteries in the neck. There are two carotid arteries, one located on each side of the neck. These arteries carry oxygenated blood from the heart to the brain and the eyes.
A carotid ultrasound looks at the structure of the carotid arteries and the blood flow through them. The ultrasound is used to detect any abnormalities in the arteries that could increase your risk of stroke.
A carotid ultrasound is used to check for any narrowing(also known as stenosis) or blockages in the carotid arteries. The carotid arteries can become narrow or blocked by a build up of plaque (consisting of substances found in the blood such as fat, cholesterol and calcium). A build-up of plaque can reduce or block the blood flow to your brain, eyes, face and neck.
Carotid ultrasounds may also be recommended if you have any health conditions that could increase the risk of you having a stroke, such as:
· High blood pressure.
· High cholesterol.
· Coronary artery disease.
· Previously experiencing a stroke.
· Recently experiencing a transient ischemic attack (TIA). This is a condition with similar symptoms to a stroke. However, the symptoms only last for a short time.
A carotid ultrasound may also be recommended for other reasons, such as:
· If you have a family history of strokes.
· If abnormal sounds (known as bruit) are detected in your carotid arteries. These sounds can be detected using a stethoscope.
· To evaluate blood flow.
· To locate tumours and blood clots.
· To evaluate the location of a stent and examine how effectively it is working.
· To assess the success of previous surgery on the carotid artery.
Identifying any issues with your arteries allows your doctor to create a treatment plan (for example, medication, a surgical procedure or life style changes) to remove or reduce the plaque and decrease the likelihood of you experiencing a stroke. The type of treatment that is recommended will depend on how narrow your arteries are and how much your blood flow is restricted.
A carotid ultrasound is a painless, non-invasive procedure. A small device (called an ultrasound probe) emits high-frequency sound waves. The sound waves bounce off different parts of the artery, creating echoes.
The probe detects these echoes and turns them into a moving image that is displayed on a monitor. The person doing your ultrasound is able to see real-time moving images of your arteries and the blood flowing through them. The images can be recorded to be analysed at a later date.
Because carotid ultrasounds are non-invasive, no preparation is required prior to the scan. You can eat and drink as normal before the scan takes place. On the day of the scan, it is recommended that you remove any jewellery or other items that cover your neck. Depending on the clothes you are wearing, you may be asked to remove an item of clothing or change into a medical gown.
At the start of the scan, you will be asked to lie down on your back with your head in a specific position. You will then have a special gel applied to your neck and the ultrasound probe will be slowly moved up and down one side of your neck. The process will then be repeated on the other side of the neck to allow the doctor to assess both of your carotid arteries.
The carotid ultrasound scan can take between 30-45 minutes, but in many cases, your scan will be much quicker than this.
Carotid ultrasounds are completely non-invasive. There are usually no side effects associated with the scan and it is extremely low risk. However, a very small number of people experience irritation or an allergic reaction to the gel. If you feel any discomfort during the scan, ensure you tell the person doing your scan.
You may also hear a carotid ultrasound scan being called a carotid duplex or a carotid doppler. If you hear either of these terms, do not worry it is the same type of scan.
In some cases, your doctor may recommend that you need an echocardiogram test alongside a carotid ultrasound. Also known as an echo or a heart echo scan, this is a type of cardiac ultrasound that examines the structure and function of the heart and the attached blood vessels.
Having both an echo and a carotid ultrasound allows your doctor to examine the vessels and arteries in more detail to look at the function of the heart and the blood flow in the arteries from the heart to the brain. This can help reduce any cardiovascular risk and the risk of stroke.