Magnetic Resonance Angiogram (MRA)
A magnetic resonance angiogram (MRA) is a type of
magnetic resonance imaging (MRI) scan that uses a
magnetic field and pulses of radio wave energy to provide pictures of blood
vessels inside the body. In many cases MRA can provide information that can't
be obtained from an
computed tomography (CT) scan.
find problems with the blood vessels that may be causing reduced blood flow.
With MRA, both the blood flow and the condition of the blood vessel walls can
be seen. The test is often used to look at the blood vessels that go to the
brain, kidneys, and legs. Information from an MRA can be saved and stored on a
computer for further study. Photographs of selected views can also be made. See
a picture of an
During MRA, the area of the body
being studied is placed inside an MRI machine.
Contrast material is often used during MRA to make
blood vessels show up more clearly.
Why It Is Done
A magnetic resonance angiogram (MRA)
is done to look for:
- A bulge (aneurysm),
clot, or the buildup of fat and calcium deposits (stenosis caused by plaque) in
the blood vessels leading to the brain.
- An aneurysm or tear (dissection) in the
aorta, which carries blood from the heart to the rest
of the body.
- Narrowing (stenosis) of the blood vessels leading to
the lungs, kidneys, or legs.
How To Prepare
Before a magnetic resonance angiogram
(MRA), tell your doctor and the MRI technologist if you:
- Are allergic to any medicines. The contrast
material used for MRA does not contain iodine. If you know that you are
allergic to the contrast material used for MRA, tell your doctor before having
- Are or might be pregnant.
- Have any metal implanted in your body. This information helps your doctor know if the test is safe for you. Tell your doctor if you have:
- Heart and blood vessel devices such as a coronary artery stent, pacemaker, ICD (implantable cardioverter-defibrillator), or metal heart
- Metal pins, clips, or metal parts in your body, including artificial limbs and dental work or braces.
- Any other implanted medical device, such as a
medicine infusion pump.
- Cosmetic metal implants, such as in your ears.
- Have an
intrauterine device (IUD) in place. An IUD may prevent
you from having the MRA test done.
- Become very nervous in small
spaces. You need to lie very still inside the MRI machine, so you may need to
have the test done with open MRI equipment. It is not as confining as standard
MRI machines. You may need medicine to help you relax. Some blood vessels may
not be seen clearly with an open MRI scanner.
- Have any other health
conditions, such as kidney problems or
sickle cell anemia, that may prevent you from having
an MRA using contrast material.
- Wear any medicine patches. The MRI may cause a burn at the patch