If you have had warning signs of a stroke (such as a “mini-stroke”) or of carotid artery disease, your physician will use several tools to make a diagnosis to determine whether the arteries in your neck that deliver blood to your brain have become narrowed, putting you at risk for a stroke.
Your treating physician will take a personal and family medical history, perform a physical exam and order tests, as indicated. To learn how emergency personnel diagnose a stroke in process, please see the SecondsCount article on Diagnosing a Stroke.
Your Medical History
Your doctor will first take your medical history, noting risk factors such as high blood pressure, diabetes or a family history of carotid artery disease. At this time, your physician will also make note of any previous signs of carotid artery disease, such as strokesor “mini-strokes,” which are events that have the symptoms of a stroke but typically resolve within 24 hours. You may also hear a “mini-stroke” called a transient ischemic attack (TIA).
The Physical Exam
Your physician will then give you a physical exam. As part of this exam, your doctor may hold a stethoscope over the carotid arteries on each side of your neck and ask you to hold your breath. If your doctor hears a whooshing sound, called a bruit, you may have narrowing of the carotid arteries. This test predicts narrowing of the arteries better than it does impending stroke, and is used as a starting point for diagnosis, rather than as confirmation of a diagnosis. In order to confirm the diagnosis, you will be recommended to undergo one or more of the imaging tests below that can identify decreased blood flow through the carotid arteries.
Diagnostic Tests for Carotid Artery Disease
Carotid artery disease is confirmed by diagnostic tests that can gather images of blood flow through the carotid arteries. These images can reveal narrowing in the arteries.
A carotid ultrasound uses harmless sound waves to create pictures of the inside of your carotid arteries. As part of this test, a Doppler ultrasound can be used to assess the quality of blood flow through the carotid arteries. Together, these tests can identify narrowing in the carotid arteries. This effective test poses no radiation risks and is painless. Learn more about ultrasound here.
Computed Tomography (CT) Angiography
During a CT scan, the patient lies on a table inside a tube. This tube takes detailed x-rays of portions of the human body at different angles to form three-dimensional images. A CT scan can give your physician extensive information about where you may have narrowing in the carotid arteries. For the test, you may also be administered contrast dye, a substance that makes it easier to see the blood vessels. A CT scan uses radiation to form images, so the benefits and risks are weighed before this type of scan is performed. Click here to learn more about computed tomography (CT) angiography here.
Magnetic Resonance Angiography (MRA)
You may have heard of magnetic resonance imaging, or MRI. Magnetic resonance angiography (MRA) is an MRI that produces images of blood vessels in the body. MRA, which is similar to a CT scan but uses no radiation, involves having a patient lie on a moveable table that slides into a tube. The machine contains a large magnet that creates a magnetic field. Pulses of radio waves are then sent and received, and a computer interprets these signals and converts them to images. The images show "slices" or sections of the body. This test can add additional information to that obtained from a vascular ultrasound or CT scan. This test does not use radiation. To learn more about magnetic resonance imaging, click here.
For this test, your physician will administer contrast dye, usually through a thin, flexible tube called a catheter that is inserted into an artery in the leg, The catheter is then passed up to the head and neck arteries. X-rays then capture images of the dye traveling through the carotid arteries in the neck. The images will indicate places where narrowing may be occurring in arteries and preventing enough oxygen-rich blood from reaching the brain.
If a diagnosis of carotid artery disease is made, your next step will be treatment. The type of treatment will vary depending on the severity of the narrowing in the carotid arteries leading to the brain. For some patients, lifestyle changes and medication will be enough. Other patients will require a minimally invasive procedure called carotid angioplasty and stenting to reopen the artery and prop it open or a surgery called carotid endarterectomy to clear the artery by removing the blockage.
It is important to remember that a stroke is a medical emergency. Go to the SecondsCount Stroke Center to learn about stroke symptoms and how a stroke is diagnosed under emergency circumstances.