What is Magnetic Resonance Angiography (MRA) of the Carotids?
Magnetic resonance angiography or 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 2 carotid arteries present on either side of your neck which carry oxygenated blood from your heart to your brain.
How does an MRA Work?
MRA scanning involves the use of radio waves that temporarily realigns hydrogen atoms in the body without causing any chemical changes. As the hydrogen atoms return to their normal position, they emit varying amounts of energy depending on the type of tissue they are present in. The MRA scanner captures the energy variation 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, which may limit the flow of blood to the brain resulting in a stroke.
Signs and Symptoms of Carotid Artery Disease
The plaque buildup within your carotid arteries, which is the characteristic feature of carotid artery disease, usually occurs slowly without causing any symptoms until the plaque becomes large enough to cause a temporary shortage of oxygenated blood to the brain resulting in a sudden onset of symptoms such as severe headache, numbness or altered sensation, loss of vision, dizziness, or trouble speaking.
Preparation for MRA of the Carotids
- Inform your doctor regarding any health conditions, previous surgeries, implants or metal placed within your body, the likelihood of pregnancy, and any allergies.
- Leave all jewelry at home. Wear loose-fitting comfortable clothing that does not contain any metal fasteners.
- Follow the dietary restrictions given by your doctor.
- Continue to take your regular medications unless otherwise specified.
Procedure for MRA of the Carotids
The procedure for magnetic resonance angiography of the carotids involves the following basic steps:
- You will be placed comfortably on a movable scanning table.
- Bolsters or straps may be used to help you remain still.
- A device containing coils that send and receive radio waves is placed around your head and neck region.
- You may be offered earplugs to muffle the noises made by the MRI machine or you can choose to listen to music through headphones during the procedure.
- An IV line will be placed into your arm to inject the contrast material as needed.
- The scanning table will be moved into the magnet of the MRI machine.
- The technologist will perform the examination from another room taking multiple pictures of the neck that each last several minutes.
- You will be required to remain as still as possible to obtain the clearest images.
- A microphone in the MRI machine allows you to talk to the technologist.
- The entire procedure will be completed in 45 -60 minutes.
What happens after MRA of the Carotids?
You can return to your routine activities and resume your normal diet immediately after the procedure. If sedation was provided to help you relax, you may have to wait until the effects of sedation wear off before returning to your routine activities. A radiologist or trained doctor will analyse the images and send the report to your doctor, who will share the results with you.
Risks of MRA of the Carotids
- The strong magnetic field produced by the MRA does not cause any harmful effects; however, implanted devices can distort images.
- You may have an allergic reaction to contrast dye. These reactions are usually mild and can be easily controlled with medication.
Benefits of MRA of the Carotids
- Produces highly detailed images of the blood vessels of 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