Carotid ultrasound uses sound waves to produce pictures of the carotid arteries in the neck which carry blood from the heart to the brain. A Doppler ultrasound study – a technique that evaluates blood flow through a blood vessel – is usually part of this exam. It’s most frequently used to screen patients for blockage or narrowing of the carotid arteries, a condition called stenosis which may increase the risk of stroke.
Little or no special preparation is required for this procedure. Leave jewelry at home and wear loose, comfortable clothing. A loose-fitting, open necked shirt or blouse is ideal.
What is Carotid Ultrasound Imaging?
Ultrasound is safe and painless, and produces pictures of the inside of the body using sound waves. Ultrasound imaging, also called ultrasound scanning or sonography, involves the use of a small transducer (probe) and ultrasound gel placed directly on the skin. High-frequency sound waves are transmitted from the probe through the gel into the body. The transducer collects the sounds that bounce back and a computer then uses those sound waves to create an image. Ultrasound examinations do not use ionizing radiation (as used in x-rays), thus there is no radiation exposure to the patient. Because ultrasound images are captured in real-time, they can show the structure and movement of the body’s internal organs, as well as blood flowing through blood vessels.
Ultrasound imaging is a noninvasive medical test that helps physicians diagnose and treat medical conditions.
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, provides detailed pictures of these blood vessels and information about the blood flowing through them.
A Doppler ultrasound study is usually an integral part of a carotid ultrasound examination.
Doppler ultrasound, also called color Doppler ultrasonography, is a special ultrasound technique that allows the physician to see and evaluate blood flow through arteries and veins in the abdomen, arms, legs, neck and/or brain (in infants and children) or within various body organs such as the liver or kidneys.
What are some common uses of the procedure?
The carotid ultrasound is most frequently performed to detect narrowing, or stenosis, of the carotid artery, a condition that substantially increases the risk of stroke.
The major goal of carotid ultrasound is to screen patients for blockage or narrowing of their carotid arteries, which if present may increase their risk of having a stroke. If a significant narrowing is detected, a comprehensive treatment may be initiated.
It may also be performed if a patient has high blood pressure or a carotid bruit (pronounced brU-E)—an abnormal sound in the neck that is heard with the stethoscope. In some cases, it is also performed in preparation for coronary artery bypass surgery. Other risk factors calling for a carotid ultrasound are:
- diabetes
- elevated blood cholesterol
- a family history of stroke or heart disease
A carotid ultrasound is also performed to:
- locate a hematoma, a collection of clotted blood that may slow and eventually stop blood flow.
- check the state of the carotid artery after surgery to restore normal blood flow.
- verify the position of a metal stent placed to maintain carotid blood flow.
Doppler ultrasound images can help the physician to see and evaluate:
- blockages to blood flow (such as clots)
- narrowing of vessels
- tumors and congenital vascular malformations
- reduced or absent blood flow to various organs
- greater than normal blood flow to different areas, which is sometimes seen in infections
In children, Doppler ultrasound is used to:
- evaluate blood flow.
- predict a higher risk of stroke in children with sickle cell disease.
- detect abnormalities in the blood vessels, lymph nodes and lymphatic vessels.
How should I prepare?
You should wear comfortable, loose-fitting clothing for your ultrasound exam. You may need to remove all clothing and jewelry in the area to be examined.
A loose-fitting, open necked shirt or blouse is ideal.
Ultrasound examinations are very sensitive to motion, and an active or crying child can prolong the examination process. To ensure a smooth experience, it often helps to explain the procedure to the child prior to the exam. Bringing books, small toys, music or games can help to distract the child and make the time pass quickly. The ultrasound exam room may have a television. Feel free to ask for your child’s favorite channel.
No other preparation is required.