Carotid Doppler Ultrasound
Developed in World War II to detect airplanes, missiles and submarines that were otherwise invisible, the Carotid Doppler Ultrasound uses sound waves to measure the flow of blood through the large carotid arteries that supply blood to the brain. This technology helps physicians monitor the carotid arteries in the neck on a viewing screen. The blood flow through these arteries is evaluated with Doppler and Color Doppler. Color Doppler involves the use of standard ultrasound methods to produce a picture of a blood vessel. In addition, a computer converts the Doppler sounds into colors (typically red and blue) that are overlaid on the image of the blood vessel. These colors represent the speed and direction of blood flow through the vessel.
Carotid Doppler studies are used to demonstrate blocked or reduced blood flow in the arteries of the neck that could cause a stroke. This test helps doctors determine stroke risk and help determine preventive measures, It is also used to evaluate symptoms of dizziness, vision changes and loss of balance that may be caused by impeded or restricted blood flow through these vessels. If you have had a TIA (mini-stroke) your doctor may order a Carotid Doppler to evaluate your carotid arteries.
What To Expect
This is a non-invasive procedure and no special preparations is necessary. The room is usually darkened for the exam. A gel is applied to the neck area to provide good contact for the handheld transducer. The transducer is placed on the neck and sound is sent into the body and is reflected off arteries and returned to the transducer. The echoes are converted electronically into images of the arteries that can be seen on a monitor. These images are recorded on paper or film. With Doppler and Color Doppler the sound waves reflected from the blood cells are converted to audible sounds that can be heard during the exam. Color is used to represent the blood flow in the artery and the speed and direction of the flow are assessed by the physician. This procedure takes approximately 45 minutes.
This test takes an average of 15 - 30 minutes for most people, though it can vary for some. Once the test is completed you will be free to resume normal activities with no restrictions.
When Will the Results of a Carotid Doppler Be Ready?
The completed test is recorded on a videotape by the ultrasound technician. The tape is reviewed by your diagnostic radiologist who measures the blood flow and determines the amount and location of any narrowing of the carotid arteries. Your radiologist will send a report to your doctor. The results should be available within a few days at most.
What are the Next Steps After Carotid Doppler?
Your doctor will review the written report provided by the radiologist. Further treatment recommendations will be based on the results of this test along with other factors as determined by your individual condition. One procedure that may be recommended is a carotid endarterectomy. This surgical procedure is done to open up constricted arteries and increase blood flow to the brain. There are other treatments that may also be recommended.