What to Expect During a Carotid Ultrasound
For most carotid ultrasounds, you are positioned lying face-up on an examination table that can be tilted or moved.
A clear water-based gel is applied to the area of the body being studied to help the transducer make secure contact with the body and eliminate air pockets between the transducer and the skin. The sonographer (ultrasound technologist) or radiologist then presses the transducer firmly against the skin and sweeps it over the area of interest.
Doppler ultrasound is performed using the same transducer.
The sonographer or radiologist is often able to review the ultrasound images in real-time as they are acquired and you can be released immediately. There may be an occasion, however, where you are asked to dress and wait while the ultrasound images are reviewed.
This ultrasound examination is usually completed within 30 minutes.
Most ultrasound examinations are painless, fast and easy.
There is usually no discomfort from pressure as the transducer is pressed against the area being examined. However, if scanning is performed over an area of tenderness, you may feel pressure or minor pain from the transducer.
It may be necessary to tilt or rotate your head for the best exposure, as the transducer is swept over the entire length of your neck on both sides to obtain views of the artery from different perspectives. It also helps to keep your arm and shoulder down. Your head will be supported to keep it still.
If a Doppler ultrasound study is performed, you may actually hear pulse-like sounds that change in pitch as the blood flow is monitored and measured.
Once the imaging is complete, the gel will be wiped off your skin.
After an ultrasound exam, you should be able to resume your normal activities within a few hours.
Limitations of Carotid Ultrasound
Carotid ultrasound may be difficult or impossible if a patient has a dressing covering a wound or surgical scar in the neck.
An occasional patient is difficult to examine because of the size or contour of the neck.
Calcium deposits in the wall of the carotid artery may make it difficult to evaluate the vessel.
A small amount of soft plaque that produces low-level echoes may go undetected.
Ultrasound cannot visualize the entire length of the vessel because the last portion of the carotid artery travels though the bone at the base of the skull. For a complete assessment, patients may need to undergo a CT or MRI of the carotid.