WHAT IS CAROTID ULTRASOUND?
Carotid ultrasound is a painless imaging test that uses high-frequency sound waves to create pictures of the inside of your carotid arteries.
The carotid arteries are a pair of blood vessels located on both sides of your neck that delivers blood to your brain and head. It is the main supplier of oxygen-rich blood to the brain. If this supply is blocked, serious complications will develop including stroke and even death.
REASON FOR CAROTID ULTRASOUND
Carotid ultrasound is most frequently used to screen patients for blocking or narrowing of carotid arteries, otherwise called stenosis. The blockage or narrowing of the carotid arteries may increase the risk of stroke.
It is common to observe a narrowing of the carotid arteries resulting from a buildup of plaque (made up of fat, cholesterol, calcium, and other substances that circulate in the bloodstream.). This medical condition may lead to transient ischemic attack (TIA).
TIA is a temporary shortage of blood flow to your brain. Your doctor will recommend carotid ultrasound if you have the following medical conditions:
- Stenosis of the carotid arteries
- Transient ischemic attack (TIA)
- High blood pressure
- Abnormal sound in carotid arteries, detected by your doctor using a stethoscope
- High cholesterol in the blood
- Coronary artery disease
- Heart disease
- Family history of stroke or heart disease
Other reasons and eligibility for carotid ultrasound include:
- To evaluate blood flow through the artery after surgery to remove plaques (carotid endarterectomy).
- To evaluate the position of the metal stent placed to maintain carotid blood flow
- To locate a hematoma, a collection of blood clots that may slow and eventually stop the flow of blood.
Doppler ultrasound images can help the doctor to view and evaluate:
- Narrowing of the vessels
- Blockages of blood flow, such as clots
- Tumors and congenital vascular malfunctions
- Increased blood flow (may be a sign of infection)
- Reduced or blocked blood flow to various organs, such as the ovary or testes.
In children, Doppler ultrasound is used for the following:
- To evaluate blood flow
- To detect abnormalities in the blood vessels, lymph nodes, and lymphatic vessels
- To predict a higher risk of stroke in those with sickle cell disease.
In nearly 50 years of experience, carotid ultrasound has proved to be a risk-free procedure. Standard diagnostic ultrasound has no known harmful effects on the beneficiaries. Ultrasound is safe and painless. It’s a non-invasive procedure and attracts no needle, injection, or incision. You don’t need an anesthetic.
Ultrasound scanners consist of a computer console, video display screen, and attached transducer. The transducer is a small hand-held device that looks like a microphone.
Some exams may use different transducer during a single exam. The transducer sends out inaudible, high-frequency sound waves into the body and listens for returning echoes.
The sonographer applies a small amount of gel on the area to be examined and places the transducer there. The gel allows sound waves to travel back and forth between the transducer and examined area. The ultrasound image is immediately visible on a video display screen (resembles a computer monitor).
The computer creates the image based on the loudness (amplitude), pitch (frequency), and time it takes for the ultrasound signal to return to the transducer. It also takes into consideration what type of body structure and/or tissue the sound is traveling through.
HOW TO PREPARE FOR CAROTID ULTRASOUND
- Call the day before the exam to confirm the time and location of the exam.
- Don’t smoke or drink caffeine over 3 hours to the test
- Wear comfortable, loose-fitting clothing. Neck less shirt or blouse is ideal.
- You don’t need jewelry, so you may leave that at home
- You may be asked to remove your clothing or jewelry during the examination
A CAROTID ULTRASOUND TECHNIQUE
The whole procedure takes about 30 – 45 minutes to complete.
Before the Procedure
- You are asked to change into a hospital gown
- You may be asked to remove your jewelry (the neckless and the long earrings)
- You will be asked to lie on your back on the exam table
During the Procedure
- The sonographer may position your head to better access the side of your neck.
- The sonographer will apply a warm gel to your skin above the site of each carotid artery.
- The sonographer will place the transducer firmly against your body, moving it back and forth over the area of interest until the desired images are captured.
- The sonographer may rotate your head for best exposure, as the transducer is swept over the entire length of the neck on both sides to obtain views of the artery from different perspectives
- The clear ultrasound gel will be wiped off your skin, once the imaging is complete.
After the Procedure
- Any un-wiped gel will be dry quickly (ultrasound gel doesn’t usually stain or discolor clothing)
- You may be asked to dress up and wait while the ultrasound images are reviewed.
- You should be able to resume your normal activities immediately.
RESULT OF CAROTID ULTRASOUND
At the end of the test:
- A neurologist will analyze the images and send a signed report to your doctor. Sometimes the neurologist may share the result with you before sending it to your doctor.
- Your doctor will discuss the result with you, on getting it.
- Your doctor may give you a follow-up appointment to enable further examination.
Reason for Follow-up Examinations
- Potential abnormality needs further evaluation
- To see if there has been any change in an abnormality over time. Your doctor may order another test.
- It’s the best way to see if treatment is working or if an abnormality is stable or has changed.
Your doctor may recommend a repeat test if he/she is not satisfied.
BENEFITS OF CAROTID ULTRASOUND
- Carotid ultrasound has no risk and no known side effects
- Most ultrasound scanning is noninvasive( no needle, no injection, no incision)
- It is not painful, is safe, and doesn’t use radiation
- Ultrasound is widely available, easy-t-use and less expensive than other imaging methods.
- It gives a clear picture of soft tissues.
LIMITATIONS OF CAROTID ULTRASOUND
- An occasional patient is difficult to examine due to the size or contour of the neck
- It may be impossible if a patient has a dressing covering a wound or surgical scar in the neck
- Calcium deposits in the wall of the carotid artery may make evaluation difficult.
- The entire length of the vessel can’t be visualized because the last portion of the carotid artery passes through the bone at the base of the skull.
- Patients may undergo a CT or MKI test.
- A small amount of soft plaque that produces low-level echoes may go undetected.
WHO SPECIALIZES IN CAROTID ULTRASOUND
Carotid ultrasound is performed by a radiologist or sonographer or a trained technologist. Sometimes an experienced medical doctor can carry out a carotid ultrasound.
Carotid ultrasounds are often done at the request of a medical practitioner, and reports (results) are also addressed to him for perusal. The images from the test will be reviewed by a board-certified cardiologist. The result may also be sent to your family doctor.
DURATION FOR RESULTS
It may take 3-4 days before you know the results of your test.
Carotid ultrasound does not have a universal fixed cost. Different countries and hospitals cost it differently. The cost for the test in the U.S ranges between $300 to $1500.
- How do I prepare for a carotid ultrasound?
You may be asked not to smoke or drink caffeine for at least two hours before the test. Smoking and caffeine use can shrink your blood vessels and affect the accuracy of the test.
Wear comfortable clothing with an open neck. Avoid turtlenecks or silk clothing which could be strained by the ultrasound gel.
- How are the results of a carotid ultrasound reviewed?
The wings from the test will be reviewed by a board-certified cardiologist. The results of the test will be sent to the doctor that ordered the test for you.
The test results will also be sent to your family doctor. It may take 3 to 4 days before you know the results of your test.
- Why would you need a carotid ultrasound?
A carotid ultrasound is performed to test for narrowed carotid arteries which increase the risk of stroke. Carotid arteries are usually narrowed by a building of plague-made up of fat, cholesterol, calcium, and other substances that circulate in the bloodstream.
- How serious is a TIA?
A TIA usually lasts only a few minutes and doesn’t cause permanent damage. Often called a ministroke, a transient ischemic attack may be a warning.
About 1 in 3 people who have a transient ischemic attack will eventually have a stroke with about half occurring within a year after the transient ischemic attack.
- How do you know if your carotid artery is blocked?
Carotid ultrasound (also called sonography) is the most common test for diagnosing carotid artery disease. It’s a painless, harmless test that uses sound waves to create pictures of the inside of your carotid arteries. The test can show whether plaque has narrowed your carotid arteries and how narrowed they are.