Magnetic resonance angiogram (MRA)

A magnetic resonance angiogram (MRA) is a noninvasive imaging exam that examines your blood vessels and blood flow. Like an MRI, it uses radio waves, a powerful magnet, and a computer to create three-dimensional (3D) images of structures inside your body. However, an MRA is specifically for finding problems in your arteries and veins such as blood clots or blockages. Unlike other types of imaging, like X-rays or CT scans, MRAs don’t use ionizing radiation.

An MRA works like an MRI, which uses a magnetic field to force hydrogen atoms in your body to align. When radio waves pass through your body, they knock the atoms out of alignment. When the atoms realign, they release energy that’s detected by a sensor. The sensor sends data to a computer that creates detailed, magnified images of blood flowing through your blood vessels. Sometimes we inject a contrast material into your bloodstream so that blood vessels show up more clearly and we can locate blockages.

An MRA is one type of angiography, which is a way to diagnose heart and blood vessel diseases. A traditional angiogram requires a needle puncture in your skin so we can guide a catheter (thin, flexible tube) through your blood vessels to the area that needs examination. Because an MRA is noninvasive, there’s no needle puncture or catheter.

In some cases, we use computed tomography angiography (CTA) instead of MRA to examine your blood vessels. CTA requires a contrast agent and uses ionizing radiation. However, CTA is usually faster than MRA and may be appropriate for people who can’t have an MRI. Your health-care provider will explain which type of angiogram is right for your needs.

We can use an MRA to examine narrowed or blocked blood vessels in any part of your body, including your head, neck, heart, limbs, chest, and abdomen. It can help us diagnose a wide range of vascular conditions and monitor the effectiveness of treatment.

We may use an MRA to evaluate:

• Aneurysms (weak, bulging area of an artery)
• Aortic dissection (tear in the aorta, which pumps blood from your heart to the rest of your body)
• Aortic stenosis (narrowed aorta)
• Atherosclerosis (plaque build-up in arteries)
• Carotid artery disease (narrowed blood vessels in the neck that supply blood to the brain)
• Arteriovenous malformations (irregular connections between veins and arteries)
• Coronary artery disease (plaque build-up in the blood vessels that supply blood to the heart)
• Deep vein thrombosis (blood clot in a deep vein, usually in the legs)
• Pulmonary embolism (blood clot in lungs)
• Renovascular hypertension (narrowed arteries that supply blood to the kidneys)

In some cases, we use an MRA to plan or guide treatments such as:

• Angioplasty and stenting: procedure to open blocked or narrowed arteries
• Coronary artery bypass graft: treatment for coronary artery disease
• Embolization: procedure to close or block blood vessels
• Stenting: implanted tube to hold blood vessels open

An MRA is a painless and noninvasive exam. An MRI technologist performs the scan. A radiologist reviews and interprets the results. The test usually takes place at a hospital or imaging facility. You can eat, drink, and take your medications normally before the scan unless your health-care provider instructs you otherwise.

Tell your technologist if you have any of the following health conditions or situations:

• Kidney disease
• Liver disease
• Pregnant or breastfeeding
• Claustrophobia (fear of enclosed spaces)

During an MRA, here’s what you can expect:

1. You remove clothing, jewelry, and any metal items and put on a gown.
2. You lie down on a padded table attached to the MRI machine, which is usually an enclosed, tube-shaped structure (some machines are open).
3. The technologist may attach a coil to the area of your body being scanned. This tells the machine where to take pictures.
4. If you need an MRA with contrast, the technologist or a nurse injects the material into a vein in your arm.
5. When the scan begins, the table moves inside the MRI machine.
6. The technologist will be in another room but can talk to you through an intercom.
7. You may hear noises such as knocking or humming as the machine takes pictures. We provide ear protection before the exam.
8. When the scan is complete, the table moves out of the machine. The scan can take up to an hour.

An MRA is an outpatient exam, so you go home the same day (unless you’re hospitalized). There’s typically no recovery time. You can drive, exercise, work, and return to other activities right away.

Some people who have an MRA with contrast experience temporary side effects such as soreness at the injection site, a mild allergic skin reaction, nausea, or headache. Tell your care team if you notice any of these issues. Drinking plenty of fluids helps flush the contrast material out of your body faster.

An MRA is a safe exam, especially because it doesn’t use ionizing radiation. However, tell your health-care provider if you have an implanted medical device. The magnetic field used during the exam can interfere with the following types of devices and cause complications:

• Artificial joint (prosthesis)
• Clips or coils for aneurysms or other vascular conditions
• Cochlear implant
• Neurostimulator
• Pacemaker or defibrillator

An MRA is an outpatient exam, so you go home the same day (unless you’re hospitalized). There’s typically no recovery time. You can drive, exercise, work, and return to other activities right away.

Some people who have an MRA with contrast experience temporary side effects such as soreness at the injection site, a mild allergic skin reaction, nausea, or headache. Tell your care team if you notice any of these issues. Drinking plenty of fluids helps flush the contrast material out of your body faster.

At Penn Medicine, you can rest assured that our board-certified radiologists have the expertise necessary to evaluate even the most complex vascular diseases using MRA and other advanced imaging techniques. When you turn to us for diagnosis and treatment, you’ll find:

• Less invasive tests: We use the most up-to-date imaging techniques to provide rapid, accurate diagnosis, without the risks or discomfort associated with more invasive procedures such as cardiac catheterization or catheter angiography.
• Customized care: Many of our imaging locations offer MRI systems that can accommodate people who are larger or claustrophobic. We’re also among the only providers in the region to offer MRI and MRA for people with pacemakers and defibrillators.
• Focus on quality: Our MRI technology uses some of the strongest magnets available to produce faster, clearer images.