An abnormal result means the artery may be narrowed or something is changing the blood flow in the carotid arteries. This is a sign of atherosclerosis (the build up and plaqueing of cholesterol to the walls of the arteries) or other blood vessel conditions. In general, the more narrowed the artery is, the higher your risk for stroke. Depending on the results, your doctor may want you to: - Consider surgery - Have additional tests (such as cerebral angiography, CT angiography, and magnetic resonance angiography) - Follow a healthy diet and lifestyle to prevent atherosclerosis - Repeat the test again in the future. Risks There are no specific risks related to having this procedure.