Magnetic Resonance Angiography (MRA) of the Carotids

What You Need to Know

Magnetic resonance angiography (MRA) of the carotids is a non-invasive, painless diagnostic imaging procedure that uses radio waves and a strong magnetic field to create detailed images of the two carotid arteries. These arteries, located on either side of your neck, carry oxygenated blood from your heart to your brain.

How Does an MRA Work?

MRA scanning involves the use of radio waves that temporarily realign hydrogen atoms in the body without causing any chemical changes. As the hydrogen atoms return to their normal positions, they emit varying amounts of energy depending on the type of tissue they
are present in. The MRA scanner captures these energy variations and creates detailed images based on this information.

Uses of Magnetic Resonance Angiography of the Carotids

An MRA of the carotids may be ordered by your doctor to help diagnose carotid artery disease (CAD) or plaque formation in the carotid arteries. Plaque buildup can limit blood flow to the brain, increasing the risk of a stroke.

Signs and Symptoms of Carotid Artery Disease

Carotid artery disease often progresses slowly and may not cause symptoms until the plaque buildup significantly restricts blood flow. Symptoms of a sudden shortage of oxygenated blood to the brain include:

Severe headache

Numbness or altered sensation

Loss of vision

Dizziness

Trouble speaking

Preparing for MRA of the Carotids

Preparation for an MRA of the carotids includes the following steps:

Inform your doctor about any health conditions, previous surgeries, implants or metal in your body, pregnancy status, and any allergies.

Leave all jewellery at home. Wear loose-fitting, comfortable clothing without metal fasteners.

Follow any dietary restrictions provided by your doctor.

Continue taking your regular medications unless advised otherwise.

The MRA Procedure

Here’s what to expect during the MRA of the carotids:

1. Preparation: You will be placed comfortably on a movable scanning table. Bolsters or straps may be used to help you remain still.

2. Equipment: A device containing coils that send and receive radio waves will be placed around your head and neck.

3. Comfort: You may be offered earplugs to muffle the noise from the MRI machine or have the option to listen to music through headphones.

4. Contrast Dye: An IV line will be placed in your arm to inject contrast material if needed.

5. Scanning: The table will move into the magnet of the MRI machine. The technologist will operate the scanner from another room, taking multiple pictures of your neck that each last several minutes. You will need to remain as still as possible to obtain clear images. A microphone in the MRI machine allows you to communicate with the
technologist.

6. Duration: The entire procedure typically takes 45-60 minutes.

After the MRA of the Carotids

You can return to your routine activities and normal diet immediately after the procedure. If sedation was provided, you may need to wait until its effects wear off before resuming normal activities. A radiologist will analyse the images and send a report to your doctor, who will share the results with you.

Risks of MRA of the Carotids

The strong magnetic field does not cause harmful effects, but implanted devices can distort images.

There is a possibility of an allergic reaction to the contrast dye, which is usually mild and manageable with medication.

Benefits of MRA of the Carotids

Produces highly detailed images of the blood vessels in the brain and associated
cranial structures.

Detects abnormalities that may be obscured by bone in other imaging studies.

Virtually no side effects, as there is no exposure to harmful radiation.

By understanding the MRA of the carotids, you can better prepare for the procedure and know what to expect, ensuring a smoother experience and clearer results.