Carotid Artery Duplex Scan
What Is a Carotid Artery Duplex Scan, and Why Am I Having It?
The carotid artery duplex scan is a noninvasive diagnostic tool done to assess the blood flow through the arteries that come from the heart through the neck and supply oxygen rich blood to the brain. It uses high pitched sound waves that are sent through a hand held device called a transducer. The transducer acts as both a sender and receiver of sound waves. As the sound waves are sent into the neck, they "hit" the carotid artery and are reflected or received back as a two dimensional picture of the carotid artery walls and then are transmitted to a video screen for viewing.
We will be able to identify where in the artery a sticky material called "plaque" might be located and whether it is causing or soon to cause a problem. Another component of the exam is called Doppler. This will measure the direction and velocity of the moving blood through the carotid artery. You will hear a "whooshing" sound on and off throughout the exam. The absence, faintness or extreme harshness of these sounds may indicate severe narrowing or obstruction of blood flow.
The test may be done to look for a cause of an abnormal sound heard in the neck with a stethoscope called a "bruit" which may indicate a disturbance in blood flow to the brain. Or you may have told your doctor that you've been having dizzy spells, periods where you feel confused or possibly a visual disturbance in one eye, and or a brief loss of your ability to move or speak. These symptoms usually occur when the carotid arteries become blocked. Also your doctor might want a periodic evaluation of a procedure performed on the obstructed carotid artery to open it up called an angioplasty or an endarterectomy.
What do I do in preparation for the test, how long does it take and when can I expect the results?
There is no preparation required for a carotid duplex exam.
Please allow up to 1 hour to complete your bilateral carotid exam. It will be done by a trained nurse or vascular technologist. The exam should cause no discomfort. You will be asked to remove any jewelry that may interfere with the exam. You may be asked to remove your shirt/blouse and if so a gown will be provided. You will lie flat on your back on an exam table. The procedure will be explained by the technologist. Your blood pressure will be taken in both arms. You will be asked to extend your neck back and look to the opposite side of the carotid artery being scanned. An ultra sonic gel will be applied to the neck.
The hand held transducer is placed on the right common carotid artery at the base of the neck and followed up to visualize the right external and right internal carotid arteries. Blood flow will be heard as a "whooshing" sound and samples of the blood's speed and direction will be taken at various locations throughout the vessel. Your right vertebral and subclavian arteries will also be examined. Once the right side is completed, the same procedure will be done to examine the left. When finished, the technologist will provide a towel to wipe the gel from your neck and assist you in getting up.
Your carotid exam will be reviewed by the cardiologist. A completed report will be sent to the referring physician within 5-7 business days, who will discuss the results with you. In the event of a significant unexpected finding, your physician will be notified by the interpreting cardiologist in an expeditious manner.
