Magnetic Resonance Angiography (MRA)

Magnetic Resonance Angiography (MRA) uses a powerful magnetic field, radio waves and a computer to evaluate blood vessels and help identify abnormalities or diagnose atherosclerotic (plaque) disease.

An MRA examination does not use ionizing radiation and may require an injection of a contrast material called gadolinium, which is less likely to cause an allergic reaction than iodinated contrast material.

What is MRA?

Magnetic Resonance Angiography (MRA) is a test that helps physicians diagnose and treat medical conditions and diseases of the blood vessels. Angiography examinations produce pictures of major blood vessels throughout the body.
 
In Magnetic Resonance Angiography (MRA), a powerful magnetic field, radio frequency waves and a computer produce detailed images of the major arteries within the body. It does not use ionizing radiation (x-rays).
 
MRA may be performed with or without contrast material. If needed, the contrast material is usually administered through a small intravenous (IV) catheter placed in a vein in your arm.

What are some common uses of the examination?

MRA is used to examine blood vessels in key areas of the body, including the:
 
  • Brain and neck
  • Heart and chest
  • Abdomen (such as the kidneys and liver)
  • Pelvis
  • Legs and feet
  • Arms and hands
 
Physicians use the procedure to:
 
  • identify abnormalities such as aneurysms, in the aorta, both in the chest and abdomen, or in other arteries.
  • detect atherosclerotic (plaque) disease in the carotid artery of the neck, which may limit blood flow to the brain and cause a stroke.
  • identify a small aneurysm or arteriovenous malformation (abnormal communications between blood vessels) inside the brain or other parts of the body.
  • detect atherosclerotic disease that has narrowed the arteries to the legs and help prepare for endovascular intervention or surgery.
  • detect disease in the arteries to the kidneys or visualize blood flow to help prepare for a kidney transplant.
  • guide interventional radiologists and surgeons making repairs to diseased blood vessels, such as implanting stents or evaluating a stent after implantation.
  • evaluate arteries feeding a tumour prior to surgery or other procedures such as chemoembolization or selective internal radiation therapy.
  • identify dissection or splitting in the aorta in the chest or abdomen or its major branches.
  • evaluate obstructions of vessels.
  • screen individuals for arterial disease, especially patients with a family history of arterial disease or disorders.     
  • On arrival, you will be asked to complete a safety questionnaire. One of our MRI Radiographers will then check through your safety questionnaire with you, and will explain the scan and answer any questions you may have.
     
    You will be asked to change into a gown and to remove any metal, for example:  jewellery, eyeglasses, watches, wigs, dentures, and hearing aids. An MRI specialist, the Radiographer, will take you into the scanning room where you will lie on the scanner table. 
     
    Devices that contain coils capable of sending and receiving radio waves may be placed around or adjacent to the area of the body being studied. 
     
    During the scan you may slowly move through the scanner. The scanner can be quite loud due to the way it works with powerful magnets. You will hear repetitive clicking, tapping and other loud noises. We will ask you, as a precaution, to wear hearing protection and for some scans you may be able to listen to the radio. During the scan you will be asked to lie very still to produce clear images. The Radiographer operating the scanner can both see and hear you clearly throughout the scan and will speak to you through an intercom connected to the headphones.
     
    The procedure is painless. You don't feel the magnetic field or radio waves, and there are no moving parts around you. Some patients find it uncomfortable to remain still during MR imaging. Others experience a sense of being closed-in (claustrophobia). Therefore, you may want to ask your physician for a prescription for a mild sedative prior to your scheduled examination, but fewer than one in 20 require medication.
     
    In some cases, a contrast dye called gadolinium, may be injected through an intravenous line into a vein in your hand or arm. The contrast is not always needed but can enhance the appearance of certain details. The contrast used during MRI scans is less likely to cause an allergic reaction than the dye used for CT scans.
     
    If you have not been sedated, no recovery period is necessary. You may resume your usual activities and normal diet immediately after the exam. On very rare occasions, patients experience hives, itchy eyes or other reactions to the contrast dye (if it was used). If you experience allergic symptoms, notify the Radiographer. A Radiologist or other physician will be available for immediate assistance.