Magnetic Resonance Angiogram

Magnetic resonance imaging (MRI) is a painless test that produces images of the inside of the body without using X-rays. During an MRI, strong magnets and radio waves work together in a magnetic field to form detailed images. MRI images may provide more details about a medical condition than X-rays, CT scans, and ultrasounds can provide.

A magnetic resonance angiogram (MRA) is an MRI done on your blood vessels. During an MRA, dye (contrast material or contrast dye) is injected into your body to make the images even clearer. An MRA provides images of blood vessels and blood flow. It can be used to help diagnose and treat heart disorders, stroke, and blood vessel diseases.

Tell a health care provider about:

• Any surgeries you have had.
• Any bleeding problems you have.
• Any allergies you have. This is especially important if you have had a previous allergic reaction to contrast dye or iodine.
• Any metal you may have in your body. The magnets used in an MRA can cause metal objects in your body to move. Metal can also make it hard to get high-quality images. Objects that may contain metal include:
  • Any joint replacement (prosthesis), such as an artificial knee or hip.
  • An implanted defibrillator, pacemaker, or neurostimulator.
  • A metallic ear implant (cochlear implant).
  • An artificial heart valve or vascular stents, filters, or coils.
  • A metallic object in the eye socket.
  • Metal splinters or bullet fragments.
  • A port for delivering insulin or chemotherapy.
• Any medical conditions you have, especially if you have kidney problems.
• All medicines you are taking, including vitamins, herbs, eye drops, creams, and over-the-counter medicines.
• Any tattoos you have. Some red dyes contain iron, which can cause problems with testing.
• Whether you are pregnant, may be pregnant, or are breastfeeding.
• Any fear of cramped spaces (claustrophobia). If this is a problem, it usually can be relieved with medicines.

What are the risks?

• If you have metal in your body, it may be affected by the magnets used during the test. If you have a metallic implant close to the area being tested, it may be hard to get high-quality images.
• If you are pregnant, you should avoid MRI tests, including MRAs, during the first 3 months of pregnancy. An MRI may have effects on an unborn baby.
• If you are breastfeeding, you may need to stop temporarily. Your breast milk may contain contrast material until the material naturally leaves your body.
• Other possible problems include:
  • Pain or irritation at the IV insertion site.
  • Allergic reaction to the contrast dye.
  • A rare reaction called nephrogenic systemic fibrosis that causes damage to skin and other organs.

What happens before the procedure?

• You will be asked to leave all jewelry at home.
• You may be asked to wear a gown.
• If you are breastfeeding, follow instructions from your health care provider about pumping before your test and stopping breastfeeding temporarily.
• You will be asked to remove all metal, including:
  • Any watches or other metal objects, like hair pins.
  • Hearing aids or dentures.
  • Mobile phone.
  • Underwire bra.
  • Makeup. Certain kinds of makeup contain small amounts of metal.

Dental braces and fillings are normally not a problem.

What happens during the procedure?

• You may be given earplugs or headphones to listen to music. The machine can be noisy.
• An IV will be inserted into one of your veins.
• Contrast material will be injected into your IV.
• You will lie down on a platform, similar to a long table.
• The platform will slide into a long tunnel that has magnets inside of it. When you are inside the tunnel, you will still be able to talk to your health care provider.
• You will be asked to lie very still while images are taken. Your health care provider will tell you when you can move. You may have to wait a few minutes to make sure that the images produced during the test are clear.
• When all images are produced, the platform will slide out of the tunnel.

The procedure may vary among health care providers and hospitals.

What can I expect after the procedure?

• If you are breastfeeding, do not breastfeed your child until your health care provider says that this is safe.
• It is up to you to get your test results. Ask your health care provider, or the department that is doing the test, when your results will be ready.

Follow these instructions at home:

Activity

• If you were given a sedative during the procedure, it can affect you for several hours. Do not drive or operate machinery until your health care provider says that it is safe.
• Return to your normal activities as told by your health care provider. Ask your health care provider what activities are safe for you.

General instructions

• Check your IV insertion area every day for signs of infection. Check for:
  • Redness, swelling, or pain.
  • Fluid or blood.
  • Warmth.
  • Pus or a bad smell.
• The contrast material will leave your body through your urine within a day. You may be told to drink plenty of fluids to help flush the contrast material out of your system.
• Keep all follow-up visits. This is important.

Contact a health care provider if:

• You have any symptoms of allergy to the contrast dye. These include:
  • Shortness of breath.
  • Rash or itchy, red, swollen areas of skin (hives).
  • A racing heartbeat.
• You have redness, swelling, warmth, pus, or pain around the IV insertion site.

Summary

• Magnetic resonance imaging (MRI) is a painless test that uses strong magnets and radio waves working together in a magnetic field to form very detailed and sharp images.
• An MRA provides images of blood vessels and blood flow.
• Before your MRA, be sure to tell your health care provider about any metal you may have in your body, any allergies, if you have kidney problems, or if you are pregnant or breastfeeding.
• Be sure to tell your health care provider if you have any fear of cramped spaces (claustrophobia).
• You may be told to drink plenty of fluids to help flush the contrast material out of your system.