Carotid Angiography

What is a carotid angiography?

Carotid angiography is a diagnostic imaging tool that uses dye, or contrast, and a special X-ray machine to study the health of veins, arteries and blood flow.

Carotid angiography is the best test available to identify and measure blockages in the carotid arteries of the neck. The test may also show whether surgery to reopen a blocked blood vessel is the best medical option, as well as determine the patient’s risk for a future stroke.

How is a carotid angiogram done?

During the test, the patient lies down and receives a mild sedative if needed to help them stay relaxed while the procedure is completed.

A nurse or physician cleans the patient’s arm or leg, and numbs the area with a local anesthetic. Once numbed, a physician inserts a thin, flexible tube, known as a catheter, into an artery. Using an X-ray for guidance, the physician threads the catheter through the artery and vein and up to the carotid artery in the neck.

Once the catheter is in place, the physician injects a special dye, which is made with iodine, through the catheter. The dye outlines blood vessels and X-ray images capture the degree of narrowing and condition of plaque in those vessels. If the plaque is rough, clots are more likely to form in the blood vessel.

How long does the procedure take?

The procedure takes from one to three hours, so patients who are undergoing the test as an outpatient should anticipate spending much of the day at Cedars-Sinai for intake and recovery.

Will the patient experience discomfort?

Patients may feel some discomfort with the initial injection of anesthetic, but the numbing agent should relieve any discomfort associated with the placement of the catheter.

Some patients experience a burning or flushing sensation in the face and head, a brief headache or nausea during the injection of the dye. However, this discomfort should pass quickly.

What should be done in advance of the test?

If the test is being done on someone who is not admitted to the hospital (outpatient), they will be asked not to eat or drink anything after midnight the evening before the test. An adult friend or family member will need to drive the patient to and from Cedars-Sinai on the day of the procedure. Patients are encouraged to wear easy-to-remove clothing, because they will be required to change into a hospital gown for the procedure.

Anyone undergoing carotid angiography should alert their physician to any medications or allergies before the test. In particular, patients should tell the medical team about:

  • History of bleeding problems
  • Past allergic reaction to X-ray contrast or any iodine-based substance
  • Current or suspected pregnancy

What should the patient expect after the test?

When the test is over, the physician will remove the IV and catheter and apply pressure to the insertion site for 10 to 20 minutes to help stop bleeding. The patient will remain in the exam room for four to six hours for monitoring. During that time, fluids are provided to prevent dehydration and to flush the contrast dye from the body.

If the procedure is being done on an outpatient basis, the patient will be allowed to go home once any bleeding has stopped and their vital signs are normal. The physician will provide follow-up instructions, which may include:

  • Eat normally
  • Continue to drink extra fluids for one or two days
  • Avoid strenuous physical activities such as climbing, driving and walking for at least 12 hours

For an appointment, a second opinion or more information, please call 1-800-CEDARS-1 (1-800-233-2771) or email us at