Magnetic Resonance Angiography

You’ve probably heard about the test called MRI. An MRI uses radio waves, a magnetic
field, and a computer create a scan of your body to look for health problems.

Magnetic resonance angiography (MRA) is a type of MRI. It looks just at the body’s
blood vessels. A regular angiogram requires inserting a thin tube (catheter) into your
body. MRA is a less invasive and less painful test.

During MRA, you lie flat inside an MRI scanner. This is a large, tunnel-like tube. In
some cases, contrast dye may be added to your bloodstream. This is done to make your
blood vessels easier to see. The contrast is put into your vein with an IV (intravenous)
needle.

If
your healthcare provider thinks that you may have a narrowing or blockage of blood
vessels somewhere in your body, he or she may advise MRA. Other conditions that your
healthcare provider can look for during this test include:

  • An
    aneurysm or weakness in the wall of an artery
  • A
    narrowing of the aorta (aortic coarctation)
  • Bleeding in and along the wall of the aorta (aortic dissection)
  • To find
    the cause of a stroke
  • Signs
    of heart disease
  • Narrowing or blockage of the vessels in the arms or legs
  • Renal
    (kidney) artery stenosis, a narrowing of the blood vessels in the kidneys that can
    lead to high blood pressure and even kidney failure

If a
dye is needed to make the blood vessels easier to see during the test, you may have a
bit of discomfort because of the insertion of the IV.

You
might also have some anxiety when placed inside the MRI scanner. This is a small, narrow
space. If you think you might be claustrophobic, be sure to tell your healthcare
provider before the scan. You may be given a mild sedative to make it easier to be in
the MRI scanner.

Some
risks of MRA include:

  • You may
    have be injured if you have metal objects in pockets or clothing or metal implants
    (such as a pacemaker or bullet fragment) in your body. Before you have the test, you
    will be asked a series of detailed questions about any metal you may have in your
    body.  
  • If you
    have a problem with your kidneys, you are at risk of a severe reaction from the MRA
    contrast dye. This reaction can affect your skin, joints, liver, and lungs. If you
    have a history of kidney disease, your healthcare provider may decide that an MRA is
    not safe for you.

Pregnant women may have additional risks in the MRI scanner. Make sure to tell your
healthcare provider if you are or might be pregnant.

You
may be at risk for other complications. This depends on your specific medical condition.
Be sure to discuss any concerns with your healthcare provider before the test.

 

Tell your healthcare provider or
the technician doing your test if you:

  • Have ever had an imaging test (MRA, MRI, or CT) with
    contrast dye
  • Are allergic to contrast dye, iodine, shellfish, or any
    medicines
  • Have a serious health problem such as diabetes or kidney
    disease
  • Are pregnant, may be pregnant, or are breastfeeding
  • Have any implanted device or metal clips or pins in your
    body

Before your test:

  • Remove
    your watch and any jewelry, coins, and other metal objects from your clothes and
    body. Don’t forget to remove earrings, ankle bracelets, and other jewelry. This
    includes pierced jewelry.
  • Tell
    your healthcare provider if you have any metal screws, surgical staples, bullet
    fragments, or other metal in your body. This includes a heart pacemaker, intrauterine
    device (IUD), implanted neurostimulator, or insulin or chemotherapy port.
  • You may
    want to ask for a blanket or a pillow to be more comfortable on the MRI scanner
    table.
  • Ear
    plugs can be helpful. The machine can be loud as it does the scan.

MRA
may be done on an outpatient basis or during a hospital stay. Generally, it follows this
process:

  1. You will remove any clothing, jewelry, or other objects that may interfere with the scan and put on a gown.
  2. If you need a contrast dye to make blood vessels easier to see, this will be given through an IV.
  3. You will be positioned on an exam table directly outside the MRI scanner.
  4. The table will slide into position, placing you inside the MRI scanner.
  5. You will need to lie still during the scanning process. Any movements can blur the images and cause the results to be less accurate.
  6. The MRI scanner typically makes a lot of noise, including loud humming noises, so don’t be alarmed.
  7. The full scan may take an hour or longer. This will depend on the type and number of blood vessels that your healthcare provider wishes to examine.

The
scan typically causes no side effects or complications. If it is done on an outpatient
basis, you are generally free to leave after the scan. Your healthcare provider will
likely schedule a follow-up appointment to review the results of the test.

Your
healthcare provider will examine the images from the MRA. If no blockages or problems
are found, you have what’s called a normal test result. An abnormal result means that
the healthcare provider noted a problem in one or more of the blood vessels in your
body. This may mean that you have hardening of the arteries (atherosclerosis) or another
blood vessel problem. Your healthcare provider will likely advise other tests or
treatments based on the results of the MRA.

Before you agree to the test or the procedure make sure you know:

  • The name of the test or procedure
  • The reason you are having the test or procedure
  • What results to expect and what they mean
  • The risks and benefits of the test or procedure
  • What the possible side effects or complications are
  • When and where you are to have the test or procedure
  • Who will do the test or procedure and what that person’s qualifications are
  • What would happen if you did not have the test or procedure
  • Any alternative tests or procedures to think about
  • When and how will you get the results
  • Who to call after the test or procedure if you have questions or problems
  • How much will you have to pay for the test or procedure