What Is the Carotid Doppler Test?

A carotid Doppler test is a vascular ultrasound performed to evaluate blood flow through the carotid arteries, which are the main arteries that supply blood to the brain, according to Johns Hopkins Medicine. The test is usually performed if a doctor suspects carotid artery blockage or narrowing.

A carotid Doppler test is generally an outpatient procedure, states Johns Hopkins Medicine. During the test, the patient must lie on his back with his neck bent back slightly. A technician applies a gel to the skin, presses a device called a transducer against the neck, and moves it around the area of the carotid artery. The technician then repeats the process on the other side of the neck. Carotid Doppler tests do not expose patients to radiation, and they usually do not cause any discomfort.

Patients who have carotid artery blockage or narrowing sometimes experience symptoms such as dizziness, confusion, drowsiness or headache that prompt a doctor to perform a carotid Doppler test, states Johns Hopkins Medicine. Other symptoms that may indicate problems with blood flow in the carotid arteries include momentary blindness in one eye or temporary problems speaking or moving. Carotid Doppler is sometimes performed as part of an evaluation prior to major cardiac surgery.