Magnetic Resonance Angiography (MRA)

What is an MRA?

Magnetic resonance angiography (MRA) is an imaging test that shows your blood vessels and blood flow. An MRA is a type of MRI that focuses on your blood vessels (arteries and veins) specifically.

An MRA can detect narrowing, widening or blockages in your blood vessels in a noninvasive way. This is unlike typical angiography, which involves inserting a catheter (tube) into a blood vessel to reach an artery.

Your healthcare provider can use MRA testing to diagnose a vascular problem, like a narrow artery. They can also use the information from an MRA to monitor changes in blood vessels and plan surgery.

They can use a magnetic resonance angiogram to look at your:

• Aorta
• Arteries of your whole body, if you have vasculitis or atherosclerosis
• Cerebral (brain) blood vessels
• Carotid (neck) arteries
• Coronary (heart) arteries
• Peripheral arteries (carry blood to your arms, hands, legs and feet)
• Pulmonary (lung) arteries
• Renal (kidney) arteries

Your provider can use an MRA test to diagnose multiple conditions, including:

• Aortic dissection
• Aneurysms
• Arteriovenous malformation
• Artery stenosis (narrowing)
• Atherosclerosis
• Congenital heart disease
• Deep vein thrombosis (DVT)
• Pulmonary embolism (PE)

A brain MRA can detect the following issues:

• Brain aneurysms
• Evidence of a stroke
• Vascular malformations

Healthcare providers may also use a brain MRA to evaluate secondary headaches.

Types

Different types of magnetic resonance angiography include:

• Contrast-enhanced MRA. This involves contrast dye. Contrast can make your blood vessels easier to see, which can help with reaching a diagnosis.
• Non-enhanced MRA. This means you don’t receive contrast dye. You may get this type of MRA if you have a health condition that makes the contrast unsafe for you.
• Two-dimensional MRA. The images are 2D. Healthcare providers typically use 2D MRA when they’re looking at long sections of a blood vessel.
• Three-dimensional MRA. The images are 3D. Providers typically use 3D MRA when they’re looking at a compact cluster of arteries, like the circle of Willis.

How does an MRA test work?

Magnetic resonance angiography uses a strong magnetic field and radio waves to create images. Your provider can see these images on a computer. Unlike an X-ray, an MRA doesn’t use radiation. It gets information from the energy your body gives off in a magnetic field.

How do I prepare for an MRA?

Your healthcare provider will ask certain questions and go over your health history before a magnetic resonance angiogram, including if:

• You have any metal in your body that could be a hazard during an MRA (or MRI). This could be a medical device or a foreign object from an accident.
• You get uncomfortable in tight spaces (claustrophobia). Your provider may suggest taking a sedative before the scan to help you relax. Or you may be able to get an “open” MRI.
• You’re pregnant or breastfeeding.
• You have any health conditions, allergies or past surgeries. If you have kidney or liver disease, you may not be able to receive contrast for the scan.

Follow your provider’s instructions for eating, drinking and taking medicine before your MRA test.

If you’re going to take a sedative before the scan, you’ll need someone to drive you home after.

What can I expect during an MRA?

In general, during an MRA, you can expect the following:

1. You’ll lie on a table that slides into and out of the MRI machine.
2. The healthcare provider will put headphones or earplugs on you to soften the machine’s loud noises.
3. They’ll remind you to lie still during the scan. Moving can cause distorted images. They may have you hold your breath for periods of time.
4. The provider will give you a small ball to hold and squeeze if you need to contact the MRI operator. They can talk with and see you from an adjoining room.
5. They’ll press a button to slide the table you’re on into the scanner. It’s a large, round device with a hole in the middle.
6. They’ll start the MRI machine and begin scanning.
7. The provider may inject a contrast agent (dye) into your IV. This may give you a metallic taste in your mouth for a short time.
8. They’ll take more images.
9. They’ll press a button to move the table you’re on out of the machine.
10. They’ll take out your IV.

An MRA usually takes 20 to 60 minutes to complete.

What are the risks of this test?

MRA is safe and noninvasive, overall. It doesn’t use radiation. An MRA doesn’t put anything into your body other than a contrast dye. If you’re at risk of problems from the dye — like if you have kidney failure — you can have the scan without it.

Some people can have side effects from the contrast dye, like a headache, upset stomach or an allergic reaction. This is rare.

What should I expect after an MRA?

If you took a sedative to relax, you’ll need someone to drive you home. If you didn’t take a sedative, you can drive yourself and go back to work or other activities right away.

When should I know the results of the test?

It will most likely take a few days for a radiologist to review your MRA scan and send the results to your healthcare provider. Contact your provider if you don’t hear back after a week.

What type of results do you get and what do the results mean?

Your healthcare provider will tell you if you have an issue in your blood vessels or another area they were examining. Based on your symptoms, they may have been looking for a certain condition. An MRA can confirm a condition and show how severe it is.

If you read the report, you may see the term “unremarkable.” This means the test was normal — they didn’t find anything concerning.