Magnetic resonance angiography – Definition
MRA is a study of the blood vessels using magnetic resonance imaging (MRI). Using a large magnet, radio waves, and a computer, an MRA makes two-dimensional and three-dimensional pictures.
Magnetic resonance angiography – Reasons for Test
This test is done to:
- Identify diseased, narrowed, enlarged, and blocked blood vessels
- Locate internal bleeding
Magnetic resonance angiography – What to Expect
Prior to Test
If your doctor prescribes a sedative:
- Arrange for a ride home.
- Do not eat or drink for at least four hours before the exam.
- Take the sedative 1-2 hours before the exam, or as directed.
At the MRI center:
- You will be asked about the following:
- Medical and surgical history
- Pregnancy
- Allergies
- Whether you have any metal objects in your body
- You will be asked if you have something in your body that would interfere with the MRA, such as:
- Pacemaker or implantable defibrillator
- Neurostimulator
- Ear implant
- Metal fragments in your eyes or in any other part of your body—Tell your doctor if your work involves metal filings or particles.
- Implanted port device, such as an insulin pump
- Metal plate, pins, screws, or surgical staples
- Metal clips from aneurysm repair
- Retained bullets
- Any other large metal objects in your body (Tooth fillings and braces are usually fine.)
- You will remove any metal objects (eg, jewelry, hearing aids, glasses) and change into a gown.
- An x-ray may be taken to check for any metal objects in your body.
You may be:
- Given ear plugs or headphones to wear (The MRI machine makes a loud banging noise.)
- Given an injection of a contrast dye into your vein
- Allowed to have a family member or friend with you during the test
Magnetic resonance angiography – Description of the Test
If contrast is used, a small IV needle will be inserted into your hand or arm before you are moved into the MRI machine. The contrast will be injected during one set of images. It helps to make some organs and vessels easier to see on the pictures. You might have an allergic reaction to the dye, but this is rare
You will lie on a special table. This table will be moved inside the opening of the MRI machine. Most MRIs will consist of 2-6 sets of images. Each one will take between 2-15 minutes. You will need to lie still while the images are being taken. You may need to hold your breath briefly. The technician will be in another room. You will be able to talk to her through an intercom.
After Test
- You will be asked to wait at the facility while the images are examined. The technician may need more images.
- If you took a sedative, do not drive or operate machinery until it wears off.
- If you are breastfeeding and receive contrast dye, you and your doctor should discuss when you should restart breastfeeding. Information available has not found any ill effects to the baby if a breastfeeding mother has had contrast dye.
- Be sure to follow your doctor’s instructions.
Magnetic resonance angiography – How Long Will It Take?
40-90 minutes
Magnetic resonance angiography – Will It Hurt?
The test is painless. However, you may notice the following:
- Loud knocking or tapping noises from the machine
- Brief stinging when the IV needle is inserted (if contrast is used)
Magnetic resonance angiography – Results
Your doctor will discuss the findings with you and any treatment you may need.
Magnetic resonance angiography – Call Your Doctor
After the test, call your doctor if any of the following occurs:
- Worsening of symptoms
- Allergic or abnormal symptoms (if contrast material was used)
In case of an emergency, call for medical help right away.
