Carotid Doppler Ultrasound

Carotid Doppler Ultrasound Preparation - click for PDFCarotid Doppler Image

For patient safety, patients exceeding the posted weight restrictions will not be done at London X-Ray Associates. The weight limit for all Ultrasound exams is 350 lbs.


Ultrasound uses sound, not x-rays, to produce images. A probe placed on the surface of the body sends a thin high-frequency sound beam (above the range that humans can hear) into the body. The sound bounces off of structures within the body and back to the probe. A computer is able to construct images based on the time required for these echoes to return. Doppler ultrasound allows us to determine the direction and speed of blood flow. Carotid Doppler ultrasound takes from 60-90 minutes.

Common Reasons for a Carotid Doppler

Some of the more common reasons why your doctor would order a carotid Doppler ultrasound include:

Who should not have a Carotid Doppler ultrasound?

Ultrasound is an extremely safe procedure and there are very few conditions that would prevent it from being performed. Since a probe must be placed in contact with the skin, ultrasound may not be possible in those with open sores or large open wounds over the area of interest. Patients that cannot lie flat on their backs for extended periods may be uncomfortable during a Carotid Doppler.

How do I prepare for the test?

There is no preparation for a Carotid Doppler ultrasound. If you wear a low neck or button up shirt or blouse, changing into a gown will not be necessary.

Who performs the examination?

An ultrasound technologist (a person trained to take ultrasound images) performs the examination. At London X-ray Associates, all of our technologists have met and maintain registration standards with the international governing body, American Registry of Diagnostic Medical Sonographers.

What happens during the examination?

After registering with the receptionist you may be asked to change into a gown, removing your shirt or blouse. You will be taken to the examination room, which contains an ultrasound machine and an examination table. You will be asked to lie on your back. Your chin must be raised from the throat area.

The technologist will ask you not to talk and avoid swallowing to decrease motion of the throat vessels. The technologist will apply gel to your skin to improve contact with the probe. The technologist will move the probe to various positions from your collarbone to your jawbone, both right and left sides, taking ultrasound pictures. When doppler is being used, you will hear a sound from the ultrasound machine. Several measurements will be taken and charted.

What can I expect after the examination?

Carotid Doppler ultrasound has no after-effects and you should be able to return to activities of daily living.

What are the risks of the procedure?

Ultrasound is an extremely safe procedure that does not expose the body to x-rays. Ultrasound transmits very small quantities of sound energy into the body but this produces no known harmful effects when standard techniques are used.

Who interprets the results and how do I get them?

The results are interpreted by one of our radiologists (a doctor trained to interpret x-rays and other medical images) and the results are sent to the doctor who ordered the ultrasound by courier or fax.

Arrangements to discuss the results of the ultrasound can be made with the doctor who ordered the test.

Are childcare (baby sitting) services available while I have my exam?

No childcare services are available. Please prearrange the following:
Adult supervision in the waiting room must be provided at all times for children while you, the caregiver, are having your exam completed. London X-Ray Associates staff will not be able to provide any childcare needs. We ask that all children be supervised by an adult, other than the patient, while at London X-Ray Associates.
Thank you.